ipn, tstime : add opt in rate limiting for netmap updates on the IPN bus

updates tailscale/corp#24553

Adds opt-in rate limiting to limit netmap updates to, at most, one every
3 seconds when the client includes the NotifyRateLimitNetmaps option
in the ipn bus watcher opts.   This should mitigate issues with excessive
memory and CPU usage in clients on large, busy tailnets.

Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>

.github/workflows/codeql-analysis.yml

@@ -49,13 +49,13 @@ jobs:
 
     # Install a more recent Go that understands modern go.mod content.
     - name: Install Go
-      uses: actions/setup-go@0a12ed9d6a96ab950c8f026ed9f722fe0da7ef32 # v5.0.2
+      uses: actions/setup-go@41dfa10bad2bb2ae585af6ee5bb4d7d973ad74ed # v5.1.0
       with:
         go-version-file: go.mod
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@6db8d6351fd0be61f9ed8ebd12ccd35dcec51fea # v3.26.11
+      uses: github/codeql-action/init@4f3212b61783c3c68e8309a0f18a699764811cda # v3.27.1
       with:
         languages: ${{ matrix.language }}
         # If you wish to specify custom queries, you can do so here or in a config file.
@@ -66,7 +66,7 @@ jobs:
     # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
     # If this step fails, then you should remove it and run the build manually (see below)
     - name: Autobuild
-      uses: github/codeql-action/autobuild@6db8d6351fd0be61f9ed8ebd12ccd35dcec51fea # v3.26.11
+      uses: github/codeql-action/autobuild@4f3212b61783c3c68e8309a0f18a699764811cda # v3.27.1
 
     # ℹ️ Command-line programs to run using the OS shell.
     # 📚 https://git.io/JvXDl
@@ -80,4 +80,4 @@ jobs:
     #   make release
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@6db8d6351fd0be61f9ed8ebd12ccd35dcec51fea # v3.26.11
+      uses: github/codeql-action/analyze@4f3212b61783c3c68e8309a0f18a699764811cda # v3.27.1

.github/workflows/golangci-lint.yml

@@ -25,7 +25,7 @@ jobs:
     steps:
       - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
 
-      - uses: actions/setup-go@0a12ed9d6a96ab950c8f026ed9f722fe0da7ef32 # v5.0.2
+      - uses: actions/setup-go@41dfa10bad2bb2ae585af6ee5bb4d7d973ad74ed # v5.1.0
         with:
           go-version-file: go.mod
           cache: false

.github/workflows/test.yml

@@ -80,7 +80,7 @@ jobs:
     - name: checkout
       uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
     - name: Restore Cache
-      uses: actions/cache@2cdf405574d6ef1f33a1d12acccd3ae82f47b3f2 # v4.1.0
+      uses: actions/cache@6849a6489940f00c2f30c0fb92c6274307ccb58a # v4.1.2
       with:
         # Note: unlike the other setups, this is only grabbing the mod download
         # cache, rather than the whole mod directory, as the download cache
@@ -153,13 +153,13 @@ jobs:
       uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
 
     - name: Install Go
-      uses: actions/setup-go@0a12ed9d6a96ab950c8f026ed9f722fe0da7ef32 # v5.0.2
+      uses: actions/setup-go@41dfa10bad2bb2ae585af6ee5bb4d7d973ad74ed # v5.1.0
       with:
         go-version-file: go.mod
         cache: false
 
     - name: Restore Cache
-      uses: actions/cache@2cdf405574d6ef1f33a1d12acccd3ae82f47b3f2 # v4.1.0
+      uses: actions/cache@6849a6489940f00c2f30c0fb92c6274307ccb58a # v4.1.2
       with:
         # Note: unlike the other setups, this is only grabbing the mod download
         # cache, rather than the whole mod directory, as the download cache
@@ -260,7 +260,7 @@ jobs:
     - name: checkout
       uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
     - name: Restore Cache
-      uses: actions/cache@2cdf405574d6ef1f33a1d12acccd3ae82f47b3f2 # v4.1.0
+      uses: actions/cache@6849a6489940f00c2f30c0fb92c6274307ccb58a # v4.1.2
       with:
         # Note: unlike the other setups, this is only grabbing the mod download
         # cache, rather than the whole mod directory, as the download cache
@@ -319,7 +319,7 @@ jobs:
     - name: checkout
       uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
     - name: Restore Cache
-      uses: actions/cache@2cdf405574d6ef1f33a1d12acccd3ae82f47b3f2 # v4.1.0
+      uses: actions/cache@6849a6489940f00c2f30c0fb92c6274307ccb58a # v4.1.2
       with:
         # Note: unlike the other setups, this is only grabbing the mod download
         # cache, rather than the whole mod directory, as the download cache
@@ -367,7 +367,7 @@ jobs:
     - name: checkout
       uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
     - name: Restore Cache
-      uses: actions/cache@2cdf405574d6ef1f33a1d12acccd3ae82f47b3f2 # v4.1.0
+      uses: actions/cache@6849a6489940f00c2f30c0fb92c6274307ccb58a # v4.1.2
       with:
         # Note: unlike the other setups, this is only grabbing the mod download
         # cache, rather than the whole mod directory, as the download cache
@@ -461,7 +461,7 @@ jobs:
       run: |
         echo "artifacts_path=$(realpath .)" >> $GITHUB_ENV
     - name: upload crash
-      uses: actions/upload-artifact@50769540e7f4bd5e21e526ee35c689e35e0d6874 # v4.4.0
+      uses: actions/upload-artifact@b4b15b8c7c6ac21ea08fcf65892d2ee8f75cf882 # v4.4.3
       if: steps.run.outcome != 'success' && steps.build.outcome == 'success'
       with:
         name: artifacts

build_docker.sh

@@ -17,12 +17,20 @@ eval "$(./build_dist.sh shellvars)"
 DEFAULT_TARGET="client"
 DEFAULT_TAGS="v${VERSION_SHORT},v${VERSION_MINOR}"
 DEFAULT_BASE="tailscale/alpine-base:3.18"
+# Set a few pre-defined OCI annotations. The source annotation is used by tools such as Renovate that scan the linked
+# Github repo to find release notes for any new image tags. Note that for official Tailscale images the default
+# annotations defined here will be overriden by release scripts that call this script.
+# https://github.com/opencontainers/image-spec/blob/main/annotations.md#pre-defined-annotation-keys
+DEFAULT_ANNOTATIONS="org.opencontainers.image.source=https://github.com/tailscale/tailscale/blob/main/build_docker.sh,org.opencontainers.image.vendor=Tailscale"
 
 PUSH="${PUSH:-false}"
 TARGET="${TARGET:-${DEFAULT_TARGET}}"
 TAGS="${TAGS:-${DEFAULT_TAGS}}"
 BASE="${BASE:-${DEFAULT_BASE}}"
 PLATFORM="${PLATFORM:-}" # default to all platforms
+# OCI annotations that will be added to the image.
+# https://github.com/opencontainers/image-spec/blob/main/annotations.md
+ANNOTATIONS="${ANNOTATIONS:-${DEFAULT_ANNOTATIONS}}"
 
 case "$TARGET" in
   client)
@@ -43,6 +51,7 @@ case "$TARGET" in
       --repos="${REPOS}" \
       --push="${PUSH}" \
       --target="${PLATFORM}" \
+      --annotations="${ANNOTATIONS}" \
       /usr/local/bin/containerboot
     ;;
   operator)
@@ -60,6 +69,7 @@ case "$TARGET" in
       --repos="${REPOS}" \
       --push="${PUSH}" \
       --target="${PLATFORM}" \
+      --annotations="${ANNOTATIONS}" \
       /usr/local/bin/operator
     ;;
   k8s-nameserver)
@@ -77,6 +87,7 @@ case "$TARGET" in
       --repos="${REPOS}" \
       --push="${PUSH}" \
       --target="${PLATFORM}" \
+      --annotations="${ANNOTATIONS}" \
       /usr/local/bin/k8s-nameserver
     ;;
   *)

client/tailscale/localclient.go

@@ -1327,6 +1327,17 @@ func (lc *LocalClient) SetServeConfig(ctx context.Context, config *ipn.ServeConf
 	return nil
 }
 
+// DisconnectControl shuts down all connections to control, thus making control consider this node inactive. This can be
+// run on HA subnet router or app connector replicas before shutting them down to ensure peers get told to switch over
+// to another replica whilst there is still some grace period for the existing connections to terminate.
+func (lc *LocalClient) DisconnectControl(ctx context.Context) error {
+	_, _, err := lc.sendWithHeaders(ctx, "POST", "/localapi/v0/disconnect-control", 200, nil, nil)
+	if err != nil {
+		return fmt.Errorf("error disconnecting control: %w", err)
+	}
+	return nil
+}
+
 // NetworkLockDisable shuts down network-lock across the tailnet.
 func (lc *LocalClient) NetworkLockDisable(ctx context.Context, secret []byte) error {
 	if _, err := lc.send(ctx, "POST", "/localapi/v0/tka/disable", 200, bytes.NewReader(secret)); err != nil {

cmd/containerboot/main.go

@@ -102,7 +102,6 @@ import (
 	"net/netip"
 	"os"
 	"os/signal"
-	"path"
 	"path/filepath"
 	"slices"
 	"strings"
@@ -731,7 +730,6 @@ func tailscaledConfigFilePath() string {
 		}
 		cv, err := kubeutils.CapVerFromFileName(e.Name())
 		if err != nil {
-			log.Printf("skipping file %q in tailscaled config directory %q: %v", e.Name(), dir, err)
 			continue
 		}
 		if cv > maxCompatVer && cv <= tailcfg.CurrentCapabilityVersion {
@@ -739,8 +737,9 @@ func tailscaledConfigFilePath() string {
 		}
 	}
 	if maxCompatVer == -1 {
-		log.Fatalf("no tailscaled config file found in %q for current capability version %q", dir, tailcfg.CurrentCapabilityVersion)
+		log.Fatalf("no tailscaled config file found in %q for current capability version %d", dir, tailcfg.CurrentCapabilityVersion)
 	}
-	log.Printf("Using tailscaled config file %q for capability version %q", maxCompatVer, tailcfg.CurrentCapabilityVersion)
-	return path.Join(dir, kubeutils.TailscaledConfigFileName(maxCompatVer))
+	filePath := filepath.Join(dir, kubeutils.TailscaledConfigFileName(maxCompatVer))
+	log.Printf("Using tailscaled config file %q to match current capability version %d", filePath, tailcfg.CurrentCapabilityVersion)
+	return filePath
 }

cmd/derper/depaware.txt

@@ -116,7 +116,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         tailscale.com/net/tlsdial/blockblame                         from tailscale.com/net/tlsdial
         tailscale.com/net/tsaddr                                     from tailscale.com/ipn+
      💣 tailscale.com/net/tshttpproxy                                from tailscale.com/derp/derphttp+
-        tailscale.com/net/wsconn                                     from tailscale.com/cmd/derper+
+        tailscale.com/net/wsconn                                     from tailscale.com/cmd/derper
         tailscale.com/paths                                          from tailscale.com/client/tailscale
      💣 tailscale.com/safesocket                                     from tailscale.com/client/tailscale
         tailscale.com/syncs                                          from tailscale.com/cmd/derper+
@@ -140,6 +140,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         tailscale.com/types/persist                                  from tailscale.com/ipn
         tailscale.com/types/preftype                                 from tailscale.com/ipn
         tailscale.com/types/ptr                                      from tailscale.com/hostinfo+
+        tailscale.com/types/result                                   from tailscale.com/util/lineiter
         tailscale.com/types/structs                                  from tailscale.com/ipn+
         tailscale.com/types/tkatype                                  from tailscale.com/client/tailscale+
         tailscale.com/types/views                                    from tailscale.com/ipn+
@@ -154,7 +155,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         tailscale.com/util/fastuuid                                  from tailscale.com/tsweb
      💣 tailscale.com/util/hashx                                     from tailscale.com/util/deephash
         tailscale.com/util/httpm                                     from tailscale.com/client/tailscale
-        tailscale.com/util/lineread                                  from tailscale.com/hostinfo+
+        tailscale.com/util/lineiter                                  from tailscale.com/hostinfo+
    L    tailscale.com/util/linuxfw                                   from tailscale.com/net/netns
         tailscale.com/util/mak                                       from tailscale.com/health+
         tailscale.com/util/multierr                                  from tailscale.com/health+
@@ -263,6 +264,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         hash/fnv                                                     from google.golang.org/protobuf/internal/detrand
         hash/maphash                                                 from go4.org/mem
         html                                                         from net/http/pprof+
+        html/template                                                from tailscale.com/cmd/derper
         io                                                           from bufio+
         io/fs                                                        from crypto/x509+
         io/ioutil                                                    from github.com/mitchellh/go-ps+
@@ -307,6 +309,8 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         sync/atomic                                                  from context+
         syscall                                                      from crypto/rand+
         text/tabwriter                                               from runtime/pprof
+        text/template                                                from html/template
+        text/template/parse                                          from html/template+
         time                                                         from compress/gzip+
         unicode                                                      from bytes+
         unicode/utf16                                                from crypto/x509+

cmd/derper/derper.go

@@ -19,6 +19,7 @@ import (
 	"expvar"
 	"flag"
 	"fmt"
+	"html/template"
 	"io"
 	"log"
 	"math"
@@ -212,25 +213,16 @@ func main() {
 		tsweb.AddBrowserHeaders(w)
 		w.Header().Set("Content-Type", "text/html; charset=utf-8")
 		w.WriteHeader(200)
-		io.WriteString(w, `<html><body>
-<h1>DERP</h1>
-<p>
-  This is a <a href="https://tailscale.com/">Tailscale</a> DERP server.
-</p>
-<p>
-  Documentation:
-</p>
-<ul>
-  <li><a href="https://tailscale.com/kb/1232/derp-servers">About DERP</a></li>
-  <li><a href="https://pkg.go.dev/tailscale.com/derp">Protocol & Go docs</a></li>
-  <li><a href="https://github.com/tailscale/tailscale/tree/main/cmd/derper#derp">How to run a DERP server</a></li>
-</ul>
-`)
-		if !*runDERP {
-			io.WriteString(w, `<p>Status: <b>disabled</b></p>`)
-		}
-		if tsweb.AllowDebugAccess(r) {
-			io.WriteString(w, "<p>Debug info at <a href='/debug/'>/debug/</a>.</p>\n")
+		err := homePageTemplate.Execute(w, templateData{
+			ShowAbuseInfo: validProdHostname.MatchString(*hostname),
+			Disabled:      !*runDERP,
+			AllowDebug:    tsweb.AllowDebugAccess(r),
+		})
+		if err != nil {
+			if r.Context().Err() == nil {
+				log.Printf("homePageTemplate.Execute: %v", err)
+			}
+			return
 		}
 	}))
 	mux.Handle("/robots.txt", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -468,3 +460,52 @@ func init() {
 		return 0
 	}))
 }
+
+type templateData struct {
+	ShowAbuseInfo bool
+	Disabled      bool
+	AllowDebug    bool
+}
+
+// homePageTemplate renders the home page using [templateData].
+var homePageTemplate = template.Must(template.New("home").Parse(`<html><body>
+<h1>DERP</h1>
+<p>
+  This is a <a href="https://tailscale.com/">Tailscale</a> DERP server.
+</p>
+
+<p>
+  It provides STUN, interactive connectivity establishment, and relaying of end-to-end encrypted traffic
+  for Tailscale clients.
+</p>
+
+{{if .ShowAbuseInfo }}
+<p>
+  If you suspect abuse, please contact <a href="mailto:security@tailscale.com">security@tailscale.com</a>.
+</p>
+{{end}}
+
+<p>
+  Documentation:
+</p>
+
+<ul>
+{{if .ShowAbuseInfo }}
+  <li><a href="https://tailscale.com/security-policies">Tailscale Security Policies</a></li>
+  <li><a href="https://tailscale.com/tailscale-aup">Tailscale Acceptable Use Policies</a></li>
+{{end}}
+  <li><a href="https://tailscale.com/kb/1232/derp-servers">About DERP</a></li>
+  <li><a href="https://pkg.go.dev/tailscale.com/derp">Protocol & Go docs</a></li>
+  <li><a href="https://github.com/tailscale/tailscale/tree/main/cmd/derper#derp">How to run a DERP server</a></li>
+</ul>
+
+{{if .Disabled}}
+<p>Status: <b>disabled</b></p>
+{{end}}
+
+{{if .AllowDebug}}
+<p>Debug info at <a href='/debug/'>/debug/</a>.</p>
+{{end}}
+</body>
+</html>
+`))

cmd/derper/derper_test.go

@@ -4,7 +4,9 @@
 package main
 
 import (
+	"bytes"
 	"context"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -110,3 +112,30 @@ func TestDeps(t *testing.T) {
 		},
 	}.Check(t)
 }
+
+func TestTemplate(t *testing.T) {
+	buf := &bytes.Buffer{}
+	err := homePageTemplate.Execute(buf, templateData{
+		ShowAbuseInfo: true,
+		Disabled:      true,
+		AllowDebug:    true,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	str := buf.String()
+	if !strings.Contains(str, "If you suspect abuse") {
+		t.Error("Output is missing abuse mailto")
+	}
+	if !strings.Contains(str, "Tailscale Security Policies") {
+		t.Error("Output is missing Tailscale Security Policies link")
+	}
+	if !strings.Contains(str, "Status:") {
+		t.Error("Output is missing disabled status")
+	}
+	if !strings.Contains(str, "Debug info") {
+		t.Error("Output is missing debug info")
+	}
+	fmt.Println(buf.String())
+}

cmd/k8s-operator/connector.go

@@ -13,7 +13,8 @@ import (
 	"sync"
 	"time"
 
-	"github.com/pkg/errors"
+	"errors"
+
 	"go.uber.org/zap"
 	xslices "golang.org/x/exp/slices"
 	corev1 "k8s.io/api/core/v1"
@@ -58,6 +59,7 @@ type ConnectorReconciler struct {
 
 	subnetRouters set.Slice[types.UID] // for subnet routers gauge
 	exitNodes     set.Slice[types.UID] // for exit nodes gauge
+	appConnectors set.Slice[types.UID] // for app connectors gauge
 }
 
 var (
@@ -67,6 +69,8 @@ var (
 	gaugeConnectorSubnetRouterResources = clientmetric.NewGauge(kubetypes.MetricConnectorWithSubnetRouterCount)
 	// gaugeConnectorExitNodeResources tracks the number of Connectors currently managed by this operator instance that are exit nodes.
 	gaugeConnectorExitNodeResources = clientmetric.NewGauge(kubetypes.MetricConnectorWithExitNodeCount)
+	// gaugeConnectorAppConnectorResources tracks the number of Connectors currently managed by this operator instance that are app connectors.
+	gaugeConnectorAppConnectorResources = clientmetric.NewGauge(kubetypes.MetricConnectorWithAppConnectorCount)
 )
 
 func (a *ConnectorReconciler) Reconcile(ctx context.Context, req reconcile.Request) (res reconcile.Result, err error) {
@@ -108,13 +112,12 @@ func (a *ConnectorReconciler) Reconcile(ctx context.Context, req reconcile.Reque
 	oldCnStatus := cn.Status.DeepCopy()
 	setStatus := func(cn *tsapi.Connector, _ tsapi.ConditionType, status metav1.ConditionStatus, reason, message string) (reconcile.Result, error) {
 		tsoperator.SetConnectorCondition(cn, tsapi.ConnectorReady, status, reason, message, cn.Generation, a.clock, logger)
+		var updateErr error
 		if !apiequality.Semantic.DeepEqual(oldCnStatus, cn.Status) {
 			// An error encountered here should get returned by the Reconcile function.
-			if updateErr := a.Client.Status().Update(ctx, cn); updateErr != nil {
-				err = errors.Wrap(err, updateErr.Error())
-			}
+			updateErr = a.Client.Status().Update(ctx, cn)
 		}
-		return res, err
+		return res, errors.Join(err, updateErr)
 	}
 
 	if !slices.Contains(cn.Finalizers, FinalizerName) {
@@ -150,6 +153,9 @@ func (a *ConnectorReconciler) Reconcile(ctx context.Context, req reconcile.Reque
 		cn.Status.SubnetRoutes = cn.Spec.SubnetRouter.AdvertiseRoutes.Stringify()
 		return setStatus(cn, tsapi.ConnectorReady, metav1.ConditionTrue, reasonConnectorCreated, reasonConnectorCreated)
 	}
+	if cn.Spec.AppConnector != nil {
+		cn.Status.IsAppConnector = true
+	}
 	cn.Status.SubnetRoutes = ""
 	return setStatus(cn, tsapi.ConnectorReady, metav1.ConditionTrue, reasonConnectorCreated, reasonConnectorCreated)
 }
@@ -189,23 +195,37 @@ func (a *ConnectorReconciler) maybeProvisionConnector(ctx context.Context, logge
 		sts.Connector.routes = cn.Spec.SubnetRouter.AdvertiseRoutes.Stringify()
 	}
 
+	if cn.Spec.AppConnector != nil {
+		sts.Connector.isAppConnector = true
+		if len(cn.Spec.AppConnector.Routes) != 0 {
+			sts.Connector.routes = cn.Spec.AppConnector.Routes.Stringify()
+		}
+	}
+
 	a.mu.Lock()
-	if sts.Connector.isExitNode {
+	if cn.Spec.ExitNode {
 		a.exitNodes.Add(cn.UID)
 	} else {
 		a.exitNodes.Remove(cn.UID)
 	}
-	if sts.Connector.routes != "" {
+	if cn.Spec.SubnetRouter != nil {
 		a.subnetRouters.Add(cn.GetUID())
 	} else {
 		a.subnetRouters.Remove(cn.GetUID())
 	}
+	if cn.Spec.AppConnector != nil {
+		a.appConnectors.Add(cn.GetUID())
+	} else {
+		a.appConnectors.Remove(cn.GetUID())
+	}
 	a.mu.Unlock()
 	gaugeConnectorSubnetRouterResources.Set(int64(a.subnetRouters.Len()))
 	gaugeConnectorExitNodeResources.Set(int64(a.exitNodes.Len()))
+	gaugeConnectorAppConnectorResources.Set(int64(a.appConnectors.Len()))
 	var connectors set.Slice[types.UID]
 	connectors.AddSlice(a.exitNodes.Slice())
 	connectors.AddSlice(a.subnetRouters.Slice())
+	connectors.AddSlice(a.appConnectors.Slice())
 	gaugeConnectorResources.Set(int64(connectors.Len()))
 
 	_, err := a.ssr.Provision(ctx, logger, sts)
@@ -248,12 +268,15 @@ func (a *ConnectorReconciler) maybeCleanupConnector(ctx context.Context, logger
 	a.mu.Lock()
 	a.subnetRouters.Remove(cn.UID)
 	a.exitNodes.Remove(cn.UID)
+	a.appConnectors.Remove(cn.UID)
 	a.mu.Unlock()
 	gaugeConnectorExitNodeResources.Set(int64(a.exitNodes.Len()))
 	gaugeConnectorSubnetRouterResources.Set(int64(a.subnetRouters.Len()))
+	gaugeConnectorAppConnectorResources.Set(int64(a.appConnectors.Len()))
 	var connectors set.Slice[types.UID]
 	connectors.AddSlice(a.exitNodes.Slice())
 	connectors.AddSlice(a.subnetRouters.Slice())
+	connectors.AddSlice(a.appConnectors.Slice())
 	gaugeConnectorResources.Set(int64(connectors.Len()))
 	return true, nil
 }
@@ -262,8 +285,14 @@ func (a *ConnectorReconciler) validate(cn *tsapi.Connector) error {
 	// Connector fields are already validated at apply time with CEL validation
 	// on custom resource fields. The checks here are a backup in case the
 	// CEL validation breaks without us noticing.
-	if !(cn.Spec.SubnetRouter != nil || cn.Spec.ExitNode) {
-		return errors.New("invalid spec: a Connector must expose subnet routes or act as an exit node (or both)")
+	if cn.Spec.SubnetRouter == nil && !cn.Spec.ExitNode && cn.Spec.AppConnector == nil {
+		return errors.New("invalid spec: a Connector must be configured as at least one of subnet router, exit node or app connector")
+	}
+	if (cn.Spec.SubnetRouter != nil || cn.Spec.ExitNode) && cn.Spec.AppConnector != nil {
+		return errors.New("invalid spec: a Connector that is configured as an app connector must not be also configured as a subnet router or exit node")
+	}
+	if cn.Spec.AppConnector != nil {
+		return validateAppConnector(cn.Spec.AppConnector)
 	}
 	if cn.Spec.SubnetRouter == nil {
 		return nil
@@ -272,19 +301,27 @@ func (a *ConnectorReconciler) validate(cn *tsapi.Connector) error {
 }
 
 func validateSubnetRouter(sb *tsapi.SubnetRouter) error {
-	if len(sb.AdvertiseRoutes) < 1 {
+	if len(sb.AdvertiseRoutes) == 0 {
 		return errors.New("invalid subnet router spec: no routes defined")
 	}
-	var err error
-	for _, route := range sb.AdvertiseRoutes {
+	return validateRoutes(sb.AdvertiseRoutes)
+}
+
+func validateAppConnector(ac *tsapi.AppConnector) error {
+	return validateRoutes(ac.Routes)
+}
+
+func validateRoutes(routes tsapi.Routes) error {
+	var errs []error
+	for _, route := range routes {
 		pfx, e := netip.ParsePrefix(string(route))
 		if e != nil {
-			err = errors.Wrap(err, fmt.Sprintf("route %s is invalid: %v", route, err))
+			errs = append(errs, fmt.Errorf("route %v is invalid: %v", route, e))
 			continue
 		}
 		if pfx.Masked() != pfx {
-			err = errors.Wrap(err, fmt.Sprintf("route %s has non-address bits set; expected %s", pfx, pfx.Masked()))
+			errs = append(errs, fmt.Errorf("route %s has non-address bits set; expected %s", pfx, pfx.Masked()))
 		}
 	}
-	return err
+	return errors.Join(errs...)
 }

cmd/k8s-operator/connector_test.go

@@ -8,12 +8,14 @@ package main
 import (
 	"context"
 	"testing"
+	"time"
 
 	"go.uber.org/zap"
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/client-go/tools/record"
 	"sigs.k8s.io/controller-runtime/pkg/client/fake"
 	tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
 	"tailscale.com/kube/kubetypes"
@@ -296,3 +298,100 @@ func TestConnectorWithProxyClass(t *testing.T) {
 	expectReconciled(t, cr, "", "test")
 	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
 }
+
+func TestConnectorWithAppConnector(t *testing.T) {
+	// Setup
+	cn := &tsapi.Connector{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "test",
+			UID:  types.UID("1234-UID"),
+		},
+		TypeMeta: metav1.TypeMeta{
+			Kind:       tsapi.ConnectorKind,
+			APIVersion: "tailscale.io/v1alpha1",
+		},
+		Spec: tsapi.ConnectorSpec{
+			AppConnector: &tsapi.AppConnector{},
+		},
+	}
+	fc := fake.NewClientBuilder().
+		WithScheme(tsapi.GlobalScheme).
+		WithObjects(cn).
+		WithStatusSubresource(cn).
+		Build()
+	ft := &fakeTSClient{}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	cl := tstest.NewClock(tstest.ClockOpts{})
+	fr := record.NewFakeRecorder(1)
+	cr := &ConnectorReconciler{
+		Client: fc,
+		clock:  cl,
+		ssr: &tailscaleSTSReconciler{
+			Client:            fc,
+			tsClient:          ft,
+			defaultTags:       []string{"tag:k8s"},
+			operatorNamespace: "operator-ns",
+			proxyImage:        "tailscale/tailscale",
+		},
+		logger:   zl.Sugar(),
+		recorder: fr,
+	}
+
+	// 1. Connector with app connnector is created and becomes ready
+	expectReconciled(t, cr, "", "test")
+	fullName, shortName := findGenName(t, fc, "", "test", "connector")
+	opts := configOpts{
+		stsName:        shortName,
+		secretName:     fullName,
+		parentType:     "connector",
+		hostname:       "test-connector",
+		app:            kubetypes.AppConnector,
+		isAppConnector: true,
+	}
+	expectEqual(t, fc, expectedSecret(t, fc, opts), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
+	// Connector's ready condition should be set to true
+
+	cn.ObjectMeta.Finalizers = append(cn.ObjectMeta.Finalizers, "tailscale.com/finalizer")
+	cn.Status.IsAppConnector = true
+	cn.Status.Conditions = []metav1.Condition{{
+		Type:               string(tsapi.ConnectorReady),
+		Status:             metav1.ConditionTrue,
+		LastTransitionTime: metav1.Time{Time: cl.Now().Truncate(time.Second)},
+		Reason:             reasonConnectorCreated,
+		Message:            reasonConnectorCreated,
+	}}
+	expectEqual(t, fc, cn, nil)
+
+	// 2. Connector with invalid app connector routes has status set to invalid
+	mustUpdate[tsapi.Connector](t, fc, "", "test", func(conn *tsapi.Connector) {
+		conn.Spec.AppConnector.Routes = tsapi.Routes{tsapi.Route("1.2.3.4/5")}
+	})
+	cn.Spec.AppConnector.Routes = tsapi.Routes{tsapi.Route("1.2.3.4/5")}
+	expectReconciled(t, cr, "", "test")
+	cn.Status.Conditions = []metav1.Condition{{
+		Type:               string(tsapi.ConnectorReady),
+		Status:             metav1.ConditionFalse,
+		LastTransitionTime: metav1.Time{Time: cl.Now().Truncate(time.Second)},
+		Reason:             reasonConnectorInvalid,
+		Message:            "Connector is invalid: route 1.2.3.4/5 has non-address bits set; expected 0.0.0.0/5",
+	}}
+	expectEqual(t, fc, cn, nil)
+
+	// 3. Connector with valid app connnector routes becomes ready
+	mustUpdate[tsapi.Connector](t, fc, "", "test", func(conn *tsapi.Connector) {
+		conn.Spec.AppConnector.Routes = tsapi.Routes{tsapi.Route("10.88.2.21/32")}
+	})
+	cn.Spec.AppConnector.Routes = tsapi.Routes{tsapi.Route("10.88.2.21/32")}
+	cn.Status.Conditions = []metav1.Condition{{
+		Type:               string(tsapi.ConnectorReady),
+		Status:             metav1.ConditionTrue,
+		LastTransitionTime: metav1.Time{Time: cl.Now().Truncate(time.Second)},
+		Reason:             reasonConnectorCreated,
+		Message:            reasonConnectorCreated,
+	}}
+	expectReconciled(t, cr, "", "test")
+}

cmd/k8s-operator/depaware.txt

@@ -80,10 +80,6 @@ tailscale.com/cmd/k8s-operator dependencies: (generated by github.com/tailscale/
         github.com/beorn7/perks/quantile                             from github.com/prometheus/client_golang/prometheus
         github.com/bits-and-blooms/bitset                            from github.com/gaissmai/bart
      💣 github.com/cespare/xxhash/v2                                 from github.com/prometheus/client_golang/prometheus
-        github.com/coder/websocket                                   from tailscale.com/control/controlhttp+
-        github.com/coder/websocket/internal/errd                     from github.com/coder/websocket
-        github.com/coder/websocket/internal/util                     from github.com/coder/websocket
-        github.com/coder/websocket/internal/xsync                    from github.com/coder/websocket
    L    github.com/coreos/go-iptables/iptables                       from tailscale.com/util/linuxfw
      💣 github.com/davecgh/go-spew/spew                              from k8s.io/apimachinery/pkg/util/dump
    W 💣 github.com/dblohm7/wingoes                                   from github.com/dblohm7/wingoes/com+
@@ -658,6 +654,7 @@ tailscale.com/cmd/k8s-operator dependencies: (generated by github.com/tailscale/
         tailscale.com/control/controlbase                            from tailscale.com/control/controlhttp+
         tailscale.com/control/controlclient                          from tailscale.com/ipn/ipnlocal+
         tailscale.com/control/controlhttp                            from tailscale.com/control/controlclient
+        tailscale.com/control/controlhttp/controlhttpcommon          from tailscale.com/control/controlhttp
         tailscale.com/control/controlknobs                           from tailscale.com/control/controlclient+
         tailscale.com/derp                                           from tailscale.com/derp/derphttp+
         tailscale.com/derp/derphttp                                  from tailscale.com/ipn/localapi+
@@ -740,7 +737,6 @@ tailscale.com/cmd/k8s-operator dependencies: (generated by github.com/tailscale/
         tailscale.com/net/tsdial                                     from tailscale.com/control/controlclient+
      💣 tailscale.com/net/tshttpproxy                                from tailscale.com/clientupdate/distsign+
         tailscale.com/net/tstun                                      from tailscale.com/tsd+
-        tailscale.com/net/wsconn                                     from tailscale.com/control/controlhttp+
         tailscale.com/omit                                           from tailscale.com/ipn/conffile
         tailscale.com/paths                                          from tailscale.com/client/tailscale+
      💣 tailscale.com/portlist                                       from tailscale.com/ipn/ipnlocal
@@ -775,6 +771,7 @@ tailscale.com/cmd/k8s-operator dependencies: (generated by github.com/tailscale/
         tailscale.com/types/persist                                  from tailscale.com/control/controlclient+
         tailscale.com/types/preftype                                 from tailscale.com/ipn+
         tailscale.com/types/ptr                                      from tailscale.com/cmd/k8s-operator+
+        tailscale.com/types/result                                   from tailscale.com/util/lineiter
         tailscale.com/types/structs                                  from tailscale.com/control/controlclient+
         tailscale.com/types/tkatype                                  from tailscale.com/client/tailscale+
         tailscale.com/types/views                                    from tailscale.com/appc+
@@ -792,7 +789,7 @@ tailscale.com/cmd/k8s-operator dependencies: (generated by github.com/tailscale/
      💣 tailscale.com/util/hashx                                     from tailscale.com/util/deephash
         tailscale.com/util/httphdr                                   from tailscale.com/ipn/ipnlocal+
         tailscale.com/util/httpm                                     from tailscale.com/client/tailscale+
-        tailscale.com/util/lineread                                  from tailscale.com/hostinfo+
+        tailscale.com/util/lineiter                                  from tailscale.com/hostinfo+
    L    tailscale.com/util/linuxfw                                   from tailscale.com/net/netns+
         tailscale.com/util/mak                                       from tailscale.com/appc+
         tailscale.com/util/multierr                                  from tailscale.com/control/controlclient+

cmd/k8s-operator/deploy/crds/tailscale.com_connectors.yaml

@@ -24,6 +24,10 @@ spec:
           jsonPath: .status.isExitNode
           name: IsExitNode
           type: string
+        - description: Whether this Connector instance is an app connector.
+          jsonPath: .status.isAppConnector
+          name: IsAppConnector
+          type: string
         - description: Status of the deployed Connector resources.
           jsonPath: .status.conditions[?(@.type == "ConnectorReady")].reason
           name: Status
@@ -66,10 +70,40 @@ spec:
                 https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
               type: object
               properties:
+                appConnector:
+                  description: |-
+                    AppConnector defines whether the Connector device should act as a Tailscale app connector. A Connector that is
+                    configured as an app connector cannot be a subnet router or an exit node. If this field is unset, the
+                    Connector does not act as an app connector.
+                    Note that you will need to manually configure the permissions and the domains for the app connector via the
+                    Admin panel.
+                    Note also that the main tested and supported use case of this config option is to deploy an app connector on
+                    Kubernetes to access SaaS applications available on the public internet. Using the app connector to expose
+                    cluster workloads or other internal workloads to tailnet might work, but this is not a use case that we have
+                    tested or optimised for.
+                    If you are using the app connector to access SaaS applications because you need a predictable egress IP that
+                    can be whitelisted, it is also your responsibility to ensure that cluster traffic from the connector flows
+                    via that predictable IP, for example by enforcing that cluster egress traffic is routed via an egress NAT
+                    device with a static IP address.
+                    https://tailscale.com/kb/1281/app-connectors
+                  type: object
+                  properties:
+                    routes:
+                      description: |-
+                        Routes are optional preconfigured routes for the domains routed via the app connector.
+                        If not set, routes for the domains will be discovered dynamically.
+                        If set, the app connector will immediately be able to route traffic using the preconfigured routes, but may
+                        also dynamically discover other routes.
+                        https://tailscale.com/kb/1332/apps-best-practices#preconfiguration
+                      type: array
+                      minItems: 1
+                      items:
+                        type: string
+                        format: cidr
                 exitNode:
                   description: |-
-                    ExitNode defines whether the Connector node should act as a
-                    Tailscale exit node. Defaults to false.
+                    ExitNode defines whether the Connector device should act as a Tailscale exit node. Defaults to false.
+                    This field is mutually exclusive with the appConnector field.
                     https://tailscale.com/kb/1103/exit-nodes
                   type: boolean
                 hostname:
@@ -90,9 +124,11 @@ spec:
                   type: string
                 subnetRouter:
                   description: |-
-                    SubnetRouter defines subnet routes that the Connector node should
-                    expose to tailnet. If unset, none are exposed.
+                    SubnetRouter defines subnet routes that the Connector device should
+                    expose to tailnet as a Tailscale subnet router.
                     https://tailscale.com/kb/1019/subnets/
+                    If this field is unset, the device does not get configured as a Tailscale subnet router.
+                    This field is mutually exclusive with the appConnector field.
                   type: object
                   required:
                     - advertiseRoutes
@@ -125,8 +161,10 @@ spec:
                     type: string
                     pattern: ^tag:[a-zA-Z][a-zA-Z0-9-]*$
               x-kubernetes-validations:
-                - rule: has(self.subnetRouter) || self.exitNode == true
-                  message: A Connector needs to be either an exit node or a subnet router, or both.
+                - rule: has(self.subnetRouter) || (has(self.exitNode) && self.exitNode == true) || has(self.appConnector)
+                  message: A Connector needs to have at least one of exit node, subnet router or app connector configured.
+                - rule: '!((has(self.subnetRouter) || (has(self.exitNode)  && self.exitNode == true)) && has(self.appConnector))'
+                  message: The appConnector field is mutually exclusive with exitNode and subnetRouter fields.
             status:
               description: |-
                 ConnectorStatus describes the status of the Connector. This is set
@@ -200,6 +238,9 @@ spec:
                     If MagicDNS is enabled in your tailnet, it is the MagicDNS name of the
                     node.
                   type: string
+                isAppConnector:
+                  description: IsAppConnector is set to true if the Connector acts as an app connector.
+                  type: boolean
                 isExitNode:
                   description: IsExitNode is set to true if the Connector acts as an exit node.
                   type: boolean

cmd/k8s-operator/deploy/manifests/operator.yaml

@@ -53,6 +53,10 @@ spec:
               jsonPath: .status.isExitNode
               name: IsExitNode
               type: string
+            - description: Whether this Connector instance is an app connector.
+              jsonPath: .status.isAppConnector
+              name: IsAppConnector
+              type: string
             - description: Status of the deployed Connector resources.
               jsonPath: .status.conditions[?(@.type == "ConnectorReady")].reason
               name: Status
@@ -91,10 +95,40 @@ spec:
                             More info:
                             https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
                         properties:
+                            appConnector:
+                                description: |-
+                                    AppConnector defines whether the Connector device should act as a Tailscale app connector. A Connector that is
+                                    configured as an app connector cannot be a subnet router or an exit node. If this field is unset, the
+                                    Connector does not act as an app connector.
+                                    Note that you will need to manually configure the permissions and the domains for the app connector via the
+                                    Admin panel.
+                                    Note also that the main tested and supported use case of this config option is to deploy an app connector on
+                                    Kubernetes to access SaaS applications available on the public internet. Using the app connector to expose
+                                    cluster workloads or other internal workloads to tailnet might work, but this is not a use case that we have
+                                    tested or optimised for.
+                                    If you are using the app connector to access SaaS applications because you need a predictable egress IP that
+                                    can be whitelisted, it is also your responsibility to ensure that cluster traffic from the connector flows
+                                    via that predictable IP, for example by enforcing that cluster egress traffic is routed via an egress NAT
+                                    device with a static IP address.
+                                    https://tailscale.com/kb/1281/app-connectors
+                                properties:
+                                    routes:
+                                        description: |-
+                                            Routes are optional preconfigured routes for the domains routed via the app connector.
+                                            If not set, routes for the domains will be discovered dynamically.
+                                            If set, the app connector will immediately be able to route traffic using the preconfigured routes, but may
+                                            also dynamically discover other routes.
+                                            https://tailscale.com/kb/1332/apps-best-practices#preconfiguration
+                                        items:
+                                            format: cidr
+                                            type: string
+                                        minItems: 1
+                                        type: array
+                                type: object
                             exitNode:
                                 description: |-
-                                    ExitNode defines whether the Connector node should act as a
-                                    Tailscale exit node. Defaults to false.
+                                    ExitNode defines whether the Connector device should act as a Tailscale exit node. Defaults to false.
+                                    This field is mutually exclusive with the appConnector field.
                                     https://tailscale.com/kb/1103/exit-nodes
                                 type: boolean
                             hostname:
@@ -115,9 +149,11 @@ spec:
                                 type: string
                             subnetRouter:
                                 description: |-
-                                    SubnetRouter defines subnet routes that the Connector node should
-                                    expose to tailnet. If unset, none are exposed.
+                                    SubnetRouter defines subnet routes that the Connector device should
+                                    expose to tailnet as a Tailscale subnet router.
                                     https://tailscale.com/kb/1019/subnets/
+                                    If this field is unset, the device does not get configured as a Tailscale subnet router.
+                                    This field is mutually exclusive with the appConnector field.
                                 properties:
                                     advertiseRoutes:
                                         description: |-
@@ -151,8 +187,10 @@ spec:
                                 type: array
                         type: object
                         x-kubernetes-validations:
-                            - message: A Connector needs to be either an exit node or a subnet router, or both.
-                              rule: has(self.subnetRouter) || self.exitNode == true
+                            - message: A Connector needs to have at least one of exit node, subnet router or app connector configured.
+                              rule: has(self.subnetRouter) || (has(self.exitNode) && self.exitNode == true) || has(self.appConnector)
+                            - message: The appConnector field is mutually exclusive with exitNode and subnetRouter fields.
+                              rule: '!((has(self.subnetRouter) || (has(self.exitNode)  && self.exitNode == true)) && has(self.appConnector))'
                     status:
                         description: |-
                             ConnectorStatus describes the status of the Connector. This is set
@@ -225,6 +263,9 @@ spec:
                                     If MagicDNS is enabled in your tailnet, it is the MagicDNS name of the
                                     node.
                                 type: string
+                            isAppConnector:
+                                description: IsAppConnector is set to true if the Connector acts as an app connector.
+                                type: boolean
                             isExitNode:
                                 description: IsExitNode is set to true if the Connector acts as an exit node.
                                 type: boolean

cmd/k8s-operator/operator.go

@@ -11,6 +11,7 @@ import (
 	"context"
 	"os"
 	"regexp"
+	"strconv"
 	"strings"
 	"time"
 
@@ -150,6 +151,13 @@ func initTSNet(zlog *zap.SugaredLogger) (*tsnet.Server, *tailscale.Client) {
 		Hostname: hostname,
 		Logf:     zlog.Named("tailscaled").Debugf,
 	}
+	if p := os.Getenv("TS_PORT"); p != "" {
+		port, err := strconv.ParseUint(p, 10, 16)
+		if err != nil {
+			startlog.Fatalf("TS_PORT %q cannot be parsed as uint16: %v", p, err)
+		}
+		s.Port = uint16(port)
+	}
 	if kubeSecret != "" {
 		st, err := kubestore.New(logger.Discard, kubeSecret)
 		if err != nil {

cmd/k8s-operator/operator_test.go

@@ -1388,7 +1388,7 @@ func TestTailscaledConfigfileHash(t *testing.T) {
 		parentType:      "svc",
 		hostname:        "default-test",
 		clusterTargetIP: "10.20.30.40",
-		confFileHash:    "e09bededa0379920141cbd0b0dbdf9b8b66545877f9e8397423f5ce3e1ba439e",
+		confFileHash:    "a67b5ad3ff605531c822327e8f1a23dd0846e1075b722c13402f7d5d0ba32ba2",
 		app:             kubetypes.AppIngressProxy,
 	}
 	expectEqual(t, fc, expectedSTS(t, fc, o), nil)
@@ -1399,7 +1399,7 @@ func TestTailscaledConfigfileHash(t *testing.T) {
 		mak.Set(&svc.Annotations, AnnotationHostname, "another-test")
 	})
 	o.hostname = "another-test"
-	o.confFileHash = "5d754cf55463135ee34aa9821f2fd8483b53eb0570c3740c84a086304f427684"
+	o.confFileHash = "888a993ebee20ad6be99623b45015339de117946850cf1252bede0b570e04293"
 	expectReconciled(t, sr, "default", "test")
 	expectEqual(t, fc, expectedSTS(t, fc, o), nil)
 }

cmd/k8s-operator/proxygroup.go

@@ -47,7 +47,7 @@ const (
 	reasonProxyGroupInvalid        = "ProxyGroupInvalid"
 )
 
-var gaugeProxyGroupResources = clientmetric.NewGauge(kubetypes.MetricProxyGroupCount)
+var gaugeProxyGroupResources = clientmetric.NewGauge(kubetypes.MetricProxyGroupEgressCount)
 
 // ProxyGroupReconciler ensures cluster resources for a ProxyGroup definition.
 type ProxyGroupReconciler struct {
@@ -353,7 +353,7 @@ func (r *ProxyGroupReconciler) deleteTailnetDevice(ctx context.Context, id tailc
 
 func (r *ProxyGroupReconciler) ensureConfigSecretsCreated(ctx context.Context, pg *tsapi.ProxyGroup, proxyClass *tsapi.ProxyClass) (hash string, err error) {
 	logger := r.logger(pg.Name)
-	var allConfigs []tailscaledConfigs
+	var configSHA256Sum string
 	for i := range pgReplicas(pg) {
 		cfgSecret := &corev1.Secret{
 			ObjectMeta: metav1.ObjectMeta{
@@ -389,7 +389,6 @@ func (r *ProxyGroupReconciler) ensureConfigSecretsCreated(ctx context.Context, p
 		if err != nil {
 			return "", fmt.Errorf("error creating tailscaled config: %w", err)
 		}
-		allConfigs = append(allConfigs, configs)
 
 		for cap, cfg := range configs {
 			cfgJSON, err := json.Marshal(cfg)
@@ -399,6 +398,32 @@ func (r *ProxyGroupReconciler) ensureConfigSecretsCreated(ctx context.Context, p
 			mak.Set(&cfgSecret.StringData, tsoperator.TailscaledConfigFileName(cap), string(cfgJSON))
 		}
 
+		// The config sha256 sum is a value for a hash annotation used to trigger
+		// pod restarts when tailscaled config changes. Any config changes apply
+		// to all replicas, so it is sufficient to only hash the config for the
+		// first replica.
+		//
+		// In future, we're aiming to eliminate restarts altogether and have
+		// pods dynamically reload their config when it changes.
+		if i == 0 {
+			sum := sha256.New()
+			for _, cfg := range configs {
+				// Zero out the auth key so it doesn't affect the sha256 hash when we
+				// remove it from the config after the pods have all authed. Otherwise
+				// all the pods will need to restart immediately after authing.
+				cfg.AuthKey = nil
+				b, err := json.Marshal(cfg)
+				if err != nil {
+					return "", err
+				}
+				if _, err := sum.Write(b); err != nil {
+					return "", err
+				}
+			}
+
+			configSHA256Sum = fmt.Sprintf("%x", sum.Sum(nil))
+		}
+
 		if existingCfgSecret != nil {
 			logger.Debugf("patching the existing ProxyGroup config Secret %s", cfgSecret.Name)
 			if err := r.Patch(ctx, cfgSecret, client.MergeFrom(existingCfgSecret)); err != nil {
@@ -412,16 +437,7 @@ func (r *ProxyGroupReconciler) ensureConfigSecretsCreated(ctx context.Context, p
 		}
 	}
 
-	sum := sha256.New()
-	b, err := json.Marshal(allConfigs)
-	if err != nil {
-		return "", err
-	}
-	if _, err := sum.Write(b); err != nil {
-		return "", err
-	}
-
-	return fmt.Sprintf("%x", sum.Sum(nil)), nil
+	return configSHA256Sum, nil
 }
 
 func pgTailscaledConfig(pg *tsapi.ProxyGroup, class *tsapi.ProxyClass, idx int32, authKey string, oldSecret *corev1.Secret) (tailscaledConfigs, error) {

cmd/k8s-operator/proxygroup_specs.go

@@ -15,6 +15,7 @@ import (
 	"sigs.k8s.io/yaml"
 	tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
 	"tailscale.com/kube/egressservices"
+	"tailscale.com/kube/kubetypes"
 	"tailscale.com/types/ptr"
 )
 
@@ -92,6 +93,10 @@ func pgStatefulSet(pg *tsapi.ProxyGroup, namespace, image, tsFirewallMode, cfgHa
 	c.Image = image
 	c.VolumeMounts = func() []corev1.VolumeMount {
 		var mounts []corev1.VolumeMount
+
+		// TODO(tomhjp): Read config directly from the secret instead. The
+		// mounts change on scaling up/down which causes unnecessary restarts
+		// for pods that haven't meaningfully changed.
 		for i := range pgReplicas(pg) {
 			mounts = append(mounts, corev1.VolumeMount{
 				Name:      fmt.Sprintf("tailscaledconfig-%d", i),
@@ -146,6 +151,10 @@ func pgStatefulSet(pg *tsapi.ProxyGroup, namespace, image, tsFirewallMode, cfgHa
 				Name:  "TS_USERSPACE",
 				Value: "false",
 			},
+			{
+				Name:  "TS_INTERNAL_APP",
+				Value: kubetypes.AppProxyGroupEgress,
+			},
 		}
 
 		if tsFirewallMode != "" {

cmd/k8s-operator/proxygroup_test.go

@@ -35,6 +35,8 @@ var defaultProxyClassAnnotations = map[string]string{
 }
 
 func TestProxyGroup(t *testing.T) {
+	const initialCfgHash = "6632726be70cf224049580deb4d317bba065915b5fd415461d60ed621c91b196"
+
 	pc := &tsapi.ProxyClass{
 		ObjectMeta: metav1.ObjectMeta{
 			Name: "default-pc",
@@ -80,6 +82,7 @@ func TestProxyGroup(t *testing.T) {
 
 		tsoperator.SetProxyGroupCondition(pg, tsapi.ProxyGroupReady, metav1.ConditionFalse, reasonProxyGroupCreating, "the ProxyGroup's ProxyClass default-pc is not yet in a ready state, waiting...", 0, cl, zl.Sugar())
 		expectEqual(t, fc, pg, nil)
+		expectProxyGroupResources(t, fc, pg, false, "")
 	})
 
 	t.Run("observe_ProxyGroupCreating_status_reason", func(t *testing.T) {
@@ -100,10 +103,11 @@ func TestProxyGroup(t *testing.T) {
 
 		tsoperator.SetProxyGroupCondition(pg, tsapi.ProxyGroupReady, metav1.ConditionFalse, reasonProxyGroupCreating, "0/2 ProxyGroup pods running", 0, cl, zl.Sugar())
 		expectEqual(t, fc, pg, nil)
+		expectProxyGroupResources(t, fc, pg, true, initialCfgHash)
 		if expected := 1; reconciler.proxyGroups.Len() != expected {
 			t.Fatalf("expected %d recorders, got %d", expected, reconciler.proxyGroups.Len())
 		}
-		expectProxyGroupResources(t, fc, pg, true)
+		expectProxyGroupResources(t, fc, pg, true, initialCfgHash)
 		keyReq := tailscale.KeyCapabilities{
 			Devices: tailscale.KeyDeviceCapabilities{
 				Create: tailscale.KeyDeviceCreateCapabilities{
@@ -135,7 +139,7 @@ func TestProxyGroup(t *testing.T) {
 		}
 		tsoperator.SetProxyGroupCondition(pg, tsapi.ProxyGroupReady, metav1.ConditionTrue, reasonProxyGroupReady, reasonProxyGroupReady, 0, cl, zl.Sugar())
 		expectEqual(t, fc, pg, nil)
-		expectProxyGroupResources(t, fc, pg, true)
+		expectProxyGroupResources(t, fc, pg, true, initialCfgHash)
 	})
 
 	t.Run("scale_up_to_3", func(t *testing.T) {
@@ -146,6 +150,7 @@ func TestProxyGroup(t *testing.T) {
 		expectReconciled(t, reconciler, "", pg.Name)
 		tsoperator.SetProxyGroupCondition(pg, tsapi.ProxyGroupReady, metav1.ConditionFalse, reasonProxyGroupCreating, "2/3 ProxyGroup pods running", 0, cl, zl.Sugar())
 		expectEqual(t, fc, pg, nil)
+		expectProxyGroupResources(t, fc, pg, true, initialCfgHash)
 
 		addNodeIDToStateSecrets(t, fc, pg)
 		expectReconciled(t, reconciler, "", pg.Name)
@@ -155,7 +160,7 @@ func TestProxyGroup(t *testing.T) {
 			TailnetIPs: []string{"1.2.3.4", "::1"},
 		})
 		expectEqual(t, fc, pg, nil)
-		expectProxyGroupResources(t, fc, pg, true)
+		expectProxyGroupResources(t, fc, pg, true, initialCfgHash)
 	})
 
 	t.Run("scale_down_to_1", func(t *testing.T) {
@@ -163,11 +168,26 @@ func TestProxyGroup(t *testing.T) {
 		mustUpdate(t, fc, "", pg.Name, func(p *tsapi.ProxyGroup) {
 			p.Spec = pg.Spec
 		})
+
 		expectReconciled(t, reconciler, "", pg.Name)
+
 		pg.Status.Devices = pg.Status.Devices[:1] // truncate to only the first device.
 		expectEqual(t, fc, pg, nil)
+		expectProxyGroupResources(t, fc, pg, true, initialCfgHash)
+	})
 
-		expectProxyGroupResources(t, fc, pg, true)
+	t.Run("trigger_config_change_and_observe_new_config_hash", func(t *testing.T) {
+		pc.Spec.TailscaleConfig = &tsapi.TailscaleConfig{
+			AcceptRoutes: true,
+		}
+		mustUpdate(t, fc, "", pc.Name, func(p *tsapi.ProxyClass) {
+			p.Spec = pc.Spec
+		})
+
+		expectReconciled(t, reconciler, "", pg.Name)
+
+		expectEqual(t, fc, pg, nil)
+		expectProxyGroupResources(t, fc, pg, true, "518a86e9fae64f270f8e0ec2a2ea6ca06c10f725035d3d6caca132cd61e42a74")
 	})
 
 	t.Run("delete_and_cleanup", func(t *testing.T) {
@@ -191,13 +211,13 @@ func TestProxyGroup(t *testing.T) {
 	})
 }
 
-func expectProxyGroupResources(t *testing.T, fc client.WithWatch, pg *tsapi.ProxyGroup, shouldExist bool) {
+func expectProxyGroupResources(t *testing.T, fc client.WithWatch, pg *tsapi.ProxyGroup, shouldExist bool, cfgHash string) {
 	t.Helper()
 
 	role := pgRole(pg, tsNamespace)
 	roleBinding := pgRoleBinding(pg, tsNamespace)
 	serviceAccount := pgServiceAccount(pg, tsNamespace)
-	statefulSet, err := pgStatefulSet(pg, tsNamespace, testProxyImage, "auto", "")
+	statefulSet, err := pgStatefulSet(pg, tsNamespace, testProxyImage, "auto", cfgHash)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -207,9 +227,7 @@ func expectProxyGroupResources(t *testing.T, fc client.WithWatch, pg *tsapi.Prox
 		expectEqual(t, fc, role, nil)
 		expectEqual(t, fc, roleBinding, nil)
 		expectEqual(t, fc, serviceAccount, nil)
-		expectEqual(t, fc, statefulSet, func(ss *appsv1.StatefulSet) {
-			ss.Spec.Template.Annotations[podAnnotationLastSetConfigFileHash] = ""
-		})
+		expectEqual(t, fc, statefulSet, nil)
 	} else {
 		expectMissing[rbacv1.Role](t, fc, role.Namespace, role.Name)
 		expectMissing[rbacv1.RoleBinding](t, fc, roleBinding.Namespace, roleBinding.Name)
@@ -218,11 +236,13 @@ func expectProxyGroupResources(t *testing.T, fc client.WithWatch, pg *tsapi.Prox
 	}
 
 	var expectedSecrets []string
-	for i := range pgReplicas(pg) {
-		expectedSecrets = append(expectedSecrets,
-			fmt.Sprintf("%s-%d", pg.Name, i),
-			fmt.Sprintf("%s-%d-config", pg.Name, i),
-		)
+	if shouldExist {
+		for i := range pgReplicas(pg) {
+			expectedSecrets = append(expectedSecrets,
+				fmt.Sprintf("%s-%d", pg.Name, i),
+				fmt.Sprintf("%s-%d-config", pg.Name, i),
+			)
+		}
 	}
 	expectSecrets(t, fc, expectedSecrets)
 }

cmd/k8s-operator/sts.go

@@ -132,10 +132,13 @@ type tailscaleSTSConfig struct {
 }
 
 type connector struct {
-	// routes is a list of subnet routes that this Connector should expose.
+	// routes is a list of routes that this Connector should advertise either as a subnet router or as an app
+	// connector.
 	routes string
 	// isExitNode defines whether this Connector should act as an exit node.
 	isExitNode bool
+	// isAppConnector defines whether this Connector should act as an app connector.
+	isAppConnector bool
 }
 type tsnetServer interface {
 	CertDomains() []string
@@ -518,11 +521,6 @@ func (a *tailscaleSTSReconciler) reconcileSTS(ctx context.Context, logger *zap.S
 			Name:  "TS_KUBE_SECRET",
 			Value: proxySecret,
 		},
-		corev1.EnvVar{
-			// Old tailscaled config key is still used for backwards compatibility.
-			Name:  "EXPERIMENTAL_TS_CONFIGFILE_PATH",
-			Value: "/etc/tsconfig/tailscaled",
-		},
 		corev1.EnvVar{
 			// New style is in the form of cap-<capability-version>.hujson.
 			Name:  "TS_EXPERIMENTAL_VERSIONED_CONFIG_DIR",
@@ -674,7 +672,7 @@ func applyProxyClassToStatefulSet(pc *tsapi.ProxyClass, ss *appsv1.StatefulSet,
 	}
 	if stsCfg != nil && pc.Spec.Metrics != nil && pc.Spec.Metrics.Enable {
 		if stsCfg.TailnetTargetFQDN == "" && stsCfg.TailnetTargetIP == "" && !stsCfg.ForwardClusterTrafficViaL7IngressProxy {
-			enableMetrics(ss, pc)
+			enableMetrics(ss)
 		} else if stsCfg.ForwardClusterTrafficViaL7IngressProxy {
 			// TODO (irbekrm): fix this
 			// For Ingress proxies that have been configured with
@@ -763,7 +761,7 @@ func applyProxyClassToStatefulSet(pc *tsapi.ProxyClass, ss *appsv1.StatefulSet,
 	return ss
 }
 
-func enableMetrics(ss *appsv1.StatefulSet, pc *tsapi.ProxyClass) {
+func enableMetrics(ss *appsv1.StatefulSet) {
 	for i, c := range ss.Spec.Template.Spec.Containers {
 		if c.Name == "tailscale" {
 			// Serve metrics on on <pod-ip>:9001/debug/metrics. If
@@ -786,15 +784,9 @@ func readAuthKey(secret *corev1.Secret, key string) (*string, error) {
 	return origConf.AuthKey, nil
 }
 
-// tailscaledConfig takes a proxy config, a newly generated auth key if
-// generated and a Secret with the previous proxy state and auth key and
-// returns tailscaled configuration and a hash of that configuration.
-//
-// As of 2024-05-09 it also returns legacy tailscaled config without the
-// later added NoStatefulFilter field to support proxies older than cap95.
-// TODO (irbekrm): remove the legacy config once we no longer need to support
-// versions older than cap94,
-// https://tailscale.com/kb/1236/kubernetes-operator#operator-and-proxies
+// tailscaledConfig takes a proxy config, a newly generated auth key if generated and a Secret with the previous proxy
+// state and auth key and returns tailscaled config files for currently supported proxy versions and a hash of that
+// configuration.
 func tailscaledConfig(stsC *tailscaleSTSConfig, newAuthkey string, oldSecret *corev1.Secret) (tailscaledConfigs, error) {
 	conf := &ipn.ConfigVAlpha{
 		Version:             "alpha0",
@@ -803,11 +795,13 @@ func tailscaledConfig(stsC *tailscaleSTSConfig, newAuthkey string, oldSecret *co
 		Locked:              "false",
 		Hostname:            &stsC.Hostname,
 		NoStatefulFiltering: "false",
+		AppConnector:        &ipn.AppConnectorPrefs{Advertise: false},
 	}
 
 	// For egress proxies only, we need to ensure that stateful filtering is
 	// not in place so that traffic from cluster can be forwarded via
 	// Tailscale IPs.
+	// TODO (irbekrm): set it to true always as this is now the default in core.
 	if stsC.TailnetTargetFQDN != "" || stsC.TailnetTargetIP != "" {
 		conf.NoStatefulFiltering = "true"
 	}
@@ -817,6 +811,9 @@ func tailscaledConfig(stsC *tailscaleSTSConfig, newAuthkey string, oldSecret *co
 			return nil, fmt.Errorf("error calculating routes: %w", err)
 		}
 		conf.AdvertiseRoutes = routes
+		if stsC.Connector.isAppConnector {
+			conf.AppConnector.Advertise = true
+		}
 	}
 	if shouldAcceptRoutes(stsC.ProxyClass) {
 		conf.AcceptRoutes = "true"
@@ -831,11 +828,13 @@ func tailscaledConfig(stsC *tailscaleSTSConfig, newAuthkey string, oldSecret *co
 		}
 		conf.AuthKey = key
 	}
+
 	capVerConfigs := make(map[tailcfg.CapabilityVersion]ipn.ConfigVAlpha)
+	capVerConfigs[107] = *conf
+
+	// AppConnector config option is only understood by clients of capver 107 and newer.
+	conf.AppConnector = nil
 	capVerConfigs[95] = *conf
-	// legacy config should not contain NoStatefulFiltering field.
-	conf.NoStatefulFiltering.Clear()
-	capVerConfigs[94] = *conf
 	return capVerConfigs, nil
 }
 

cmd/k8s-operator/testutils_test.go

@@ -48,6 +48,7 @@ type configOpts struct {
 	clusterTargetDNS                               string
 	subnetRoutes                                   string
 	isExitNode                                     bool
+	isAppConnector                                 bool
 	confFileHash                                   string
 	serveConfig                                    *ipn.ServeConfig
 	shouldEnableForwardingClusterTrafficViaIngress bool
@@ -70,7 +71,6 @@ func expectedSTS(t *testing.T, cl client.Client, opts configOpts) *appsv1.Statef
 			{Name: "TS_USERSPACE", Value: "false"},
 			{Name: "POD_IP", ValueFrom: &corev1.EnvVarSource{FieldRef: &corev1.ObjectFieldSelector{APIVersion: "", FieldPath: "status.podIP"}, ResourceFieldRef: nil, ConfigMapKeyRef: nil, SecretKeyRef: nil}},
 			{Name: "TS_KUBE_SECRET", Value: opts.secretName},
-			{Name: "EXPERIMENTAL_TS_CONFIGFILE_PATH", Value: "/etc/tsconfig/tailscaled"},
 			{Name: "TS_EXPERIMENTAL_VERSIONED_CONFIG_DIR", Value: "/etc/tsconfig"},
 		},
 		SecurityContext: &corev1.SecurityContext{
@@ -229,7 +229,6 @@ func expectedSTSUserspace(t *testing.T, cl client.Client, opts configOpts) *apps
 			{Name: "TS_USERSPACE", Value: "true"},
 			{Name: "POD_IP", ValueFrom: &corev1.EnvVarSource{FieldRef: &corev1.ObjectFieldSelector{APIVersion: "", FieldPath: "status.podIP"}, ResourceFieldRef: nil, ConfigMapKeyRef: nil, SecretKeyRef: nil}},
 			{Name: "TS_KUBE_SECRET", Value: opts.secretName},
-			{Name: "EXPERIMENTAL_TS_CONFIGFILE_PATH", Value: "/etc/tsconfig/tailscaled"},
 			{Name: "TS_EXPERIMENTAL_VERSIONED_CONFIG_DIR", Value: "/etc/tsconfig"},
 			{Name: "TS_SERVE_CONFIG", Value: "/etc/tailscaled/serve-config"},
 			{Name: "TS_INTERNAL_APP", Value: opts.app},
@@ -356,6 +355,7 @@ func expectedSecret(t *testing.T, cl client.Client, opts configOpts) *corev1.Sec
 		Locked:       "false",
 		AuthKey:      ptr.To("secret-authkey"),
 		AcceptRoutes: "false",
+		AppConnector: &ipn.AppConnectorPrefs{Advertise: false},
 	}
 	if opts.proxyClass != "" {
 		t.Logf("applying configuration from ProxyClass %s", opts.proxyClass)
@@ -370,6 +370,9 @@ func expectedSecret(t *testing.T, cl client.Client, opts configOpts) *corev1.Sec
 	if opts.shouldRemoveAuthKey {
 		conf.AuthKey = nil
 	}
+	if opts.isAppConnector {
+		conf.AppConnector = &ipn.AppConnectorPrefs{Advertise: true}
+	}
 	var routes []netip.Prefix
 	if opts.subnetRoutes != "" || opts.isExitNode {
 		r := opts.subnetRoutes
@@ -384,22 +387,23 @@ func expectedSecret(t *testing.T, cl client.Client, opts configOpts) *corev1.Sec
 			routes = append(routes, prefix)
 		}
 	}
-	conf.AdvertiseRoutes = routes
-	b, err := json.Marshal(conf)
-	if err != nil {
-		t.Fatalf("error marshalling tailscaled config")
-	}
 	if opts.tailnetTargetFQDN != "" || opts.tailnetTargetIP != "" {
 		conf.NoStatefulFiltering = "true"
 	} else {
 		conf.NoStatefulFiltering = "false"
 	}
+	conf.AdvertiseRoutes = routes
+	bnn, err := json.Marshal(conf)
+	if err != nil {
+		t.Fatalf("error marshalling tailscaled config")
+	}
+	conf.AppConnector = nil
 	bn, err := json.Marshal(conf)
 	if err != nil {
 		t.Fatalf("error marshalling tailscaled config")
 	}
-	mak.Set(&s.StringData, "tailscaled", string(b))
 	mak.Set(&s.StringData, "cap-95.hujson", string(bn))
+	mak.Set(&s.StringData, "cap-107.hujson", string(bnn))
 	labels := map[string]string{
 		"tailscale.com/managed":              "true",
 		"tailscale.com/parent-resource":      "test",
@@ -650,18 +654,6 @@ func removeTargetPortsFromSvc(svc *corev1.Service) {
 func removeAuthKeyIfExistsModifier(t *testing.T) func(s *corev1.Secret) {
 	return func(secret *corev1.Secret) {
 		t.Helper()
-		if len(secret.StringData["tailscaled"]) != 0 {
-			conf := &ipn.ConfigVAlpha{}
-			if err := json.Unmarshal([]byte(secret.StringData["tailscaled"]), conf); err != nil {
-				t.Fatalf("error unmarshalling 'tailscaled' contents: %v", err)
-			}
-			conf.AuthKey = nil
-			b, err := json.Marshal(conf)
-			if err != nil {
-				t.Fatalf("error marshalling updated 'tailscaled' config: %v", err)
-			}
-			mak.Set(&secret.StringData, "tailscaled", string(b))
-		}
 		if len(secret.StringData["cap-95.hujson"]) != 0 {
 			conf := &ipn.ConfigVAlpha{}
 			if err := json.Unmarshal([]byte(secret.StringData["cap-95.hujson"]), conf); err != nil {
@@ -674,5 +666,17 @@ func removeAuthKeyIfExistsModifier(t *testing.T) func(s *corev1.Secret) {
 			}
 			mak.Set(&secret.StringData, "cap-95.hujson", string(b))
 		}
+		if len(secret.StringData["cap-107.hujson"]) != 0 {
+			conf := &ipn.ConfigVAlpha{}
+			if err := json.Unmarshal([]byte(secret.StringData["cap-107.hujson"]), conf); err != nil {
+				t.Fatalf("error umarshalling 'cap-107.hujson' contents: %v", err)
+			}
+			conf.AuthKey = nil
+			b, err := json.Marshal(conf)
+			if err != nil {
+				t.Fatalf("error marshalling 'cap-107.huson' contents: %v", err)
+			}
+			mak.Set(&secret.StringData, "cap-107.hujson", string(b))
+		}
 	}
 }

cmd/stund/depaware.txt

@@ -67,6 +67,7 @@ tailscale.com/cmd/stund dependencies: (generated by github.com/tailscale/depawar
         tailscale.com/types/logger                                   from tailscale.com/tsweb
         tailscale.com/types/opt                                      from tailscale.com/envknob+
         tailscale.com/types/ptr                                      from tailscale.com/tailcfg+
+        tailscale.com/types/result                                   from tailscale.com/util/lineiter
         tailscale.com/types/structs                                  from tailscale.com/tailcfg+
         tailscale.com/types/tkatype                                  from tailscale.com/tailcfg+
         tailscale.com/types/views                                    from tailscale.com/net/tsaddr+
@@ -74,7 +75,7 @@ tailscale.com/cmd/stund dependencies: (generated by github.com/tailscale/depawar
    L 💣 tailscale.com/util/dirwalk                                   from tailscale.com/metrics
         tailscale.com/util/dnsname                                   from tailscale.com/tailcfg
         tailscale.com/util/fastuuid                                  from tailscale.com/tsweb
-        tailscale.com/util/lineread                                  from tailscale.com/version/distro
+        tailscale.com/util/lineiter                                  from tailscale.com/version/distro
         tailscale.com/util/nocasemaps                                from tailscale.com/types/ipproto
         tailscale.com/util/slicesx                                   from tailscale.com/tailcfg
         tailscale.com/util/vizerror                                  from tailscale.com/tailcfg+

cmd/tailscale/cli/cli.go

@@ -93,8 +93,13 @@ func Run(args []string) (err error) {
 
 	args = CleanUpArgs(args)
 
-	if len(args) == 1 && (args[0] == "-V" || args[0] == "--version") {
-		args = []string{"version"}
+	if len(args) == 1 {
+		switch args[0] {
+		case "-V", "--version":
+			args = []string{"version"}
+		case "help":
+			args = []string{"--help"}
+		}
 	}
 
 	var warnOnce sync.Once

cmd/tailscale/cli/cli_test.go

@@ -9,6 +9,7 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+	"io"
 	"net/netip"
 	"reflect"
 	"strings"
@@ -1480,3 +1481,33 @@ func TestParseNLArgs(t *testing.T) {
 		})
 	}
 }
+
+func TestHelpAlias(t *testing.T) {
+	var stdout, stderr bytes.Buffer
+	tstest.Replace[io.Writer](t, &Stdout, &stdout)
+	tstest.Replace[io.Writer](t, &Stderr, &stderr)
+
+	gotExit0 := false
+	defer func() {
+		if !gotExit0 {
+			t.Error("expected os.Exit(0) to be called")
+			return
+		}
+		if !strings.Contains(stderr.String(), "SUBCOMMANDS") {
+			t.Errorf("expected help output to contain SUBCOMMANDS; got stderr=%q; stdout=%q", stderr.String(), stdout.String())
+		}
+	}()
+	defer func() {
+		if e := recover(); e != nil {
+			if strings.Contains(fmt.Sprint(e), "unexpected call to os.Exit(0)") {
+				gotExit0 = true
+			} else {
+				t.Errorf("unexpected panic: %v", e)
+			}
+		}
+	}()
+	err := Run([]string{"help"})
+	if err != nil {
+		t.Fatalf("Run: %v", err)
+	}
+}

cmd/tailscale/depaware.txt

@@ -5,10 +5,6 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
    W 💣 github.com/alexbrainman/sspi                                 from github.com/alexbrainman/sspi/internal/common+
    W    github.com/alexbrainman/sspi/internal/common                 from github.com/alexbrainman/sspi/negotiate
    W 💣 github.com/alexbrainman/sspi/negotiate                       from tailscale.com/net/tshttpproxy
-        github.com/coder/websocket                                   from tailscale.com/control/controlhttp+
-        github.com/coder/websocket/internal/errd                     from github.com/coder/websocket
-        github.com/coder/websocket/internal/util                     from github.com/coder/websocket
-        github.com/coder/websocket/internal/xsync                    from github.com/coder/websocket
    L    github.com/coreos/go-iptables/iptables                       from tailscale.com/util/linuxfw
    W 💣 github.com/dblohm7/wingoes                                   from github.com/dblohm7/wingoes/pe+
    W 💣 github.com/dblohm7/wingoes/pe                                from tailscale.com/util/winutil/authenticode
@@ -86,6 +82,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/cmd/tailscale/cli/ffcomplete/internal          from tailscale.com/cmd/tailscale/cli/ffcomplete
         tailscale.com/control/controlbase                            from tailscale.com/control/controlhttp+
         tailscale.com/control/controlhttp                            from tailscale.com/cmd/tailscale/cli
+        tailscale.com/control/controlhttp/controlhttpcommon          from tailscale.com/control/controlhttp
         tailscale.com/control/controlknobs                           from tailscale.com/net/portmapper
         tailscale.com/derp                                           from tailscale.com/derp/derphttp
         tailscale.com/derp/derphttp                                  from tailscale.com/net/netcheck
@@ -124,7 +121,6 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/net/tlsdial/blockblame                         from tailscale.com/net/tlsdial
         tailscale.com/net/tsaddr                                     from tailscale.com/client/web+
      💣 tailscale.com/net/tshttpproxy                                from tailscale.com/clientupdate/distsign+
-        tailscale.com/net/wsconn                                     from tailscale.com/control/controlhttp+
         tailscale.com/paths                                          from tailscale.com/client/tailscale+
      💣 tailscale.com/safesocket                                     from tailscale.com/client/tailscale+
         tailscale.com/syncs                                          from tailscale.com/cmd/tailscale/cli+
@@ -148,6 +144,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/types/persist                                  from tailscale.com/ipn
         tailscale.com/types/preftype                                 from tailscale.com/cmd/tailscale/cli+
         tailscale.com/types/ptr                                      from tailscale.com/hostinfo+
+        tailscale.com/types/result                                   from tailscale.com/util/lineiter
         tailscale.com/types/structs                                  from tailscale.com/ipn+
         tailscale.com/types/tkatype                                  from tailscale.com/types/key+
         tailscale.com/types/views                                    from tailscale.com/tailcfg+
@@ -162,7 +159,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/util/groupmember                               from tailscale.com/client/web
      💣 tailscale.com/util/hashx                                     from tailscale.com/util/deephash
         tailscale.com/util/httpm                                     from tailscale.com/client/tailscale+
-        tailscale.com/util/lineread                                  from tailscale.com/hostinfo+
+        tailscale.com/util/lineiter                                  from tailscale.com/hostinfo+
    L    tailscale.com/util/linuxfw                                   from tailscale.com/net/netns
         tailscale.com/util/mak                                       from tailscale.com/cmd/tailscale/cli+
         tailscale.com/util/multierr                                  from tailscale.com/control/controlhttp+
@@ -324,7 +321,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         reflect                                                      from archive/tar+
         regexp                                                       from github.com/coreos/go-iptables/iptables+
         regexp/syntax                                                from regexp
-        runtime/debug                                                from github.com/coder/websocket/internal/xsync+
+        runtime/debug                                                from tailscale.com+
         slices                                                       from tailscale.com/client/web+
         sort                                                         from compress/flate+
         strconv                                                      from archive/tar+

cmd/tailscaled/depaware.txt

@@ -79,10 +79,6 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
    L    github.com/aws/smithy-go/transport/http/internal/io          from github.com/aws/smithy-go/transport/http
    L    github.com/aws/smithy-go/waiter                              from github.com/aws/aws-sdk-go-v2/service/ssm
         github.com/bits-and-blooms/bitset                            from github.com/gaissmai/bart
-        github.com/coder/websocket                                   from tailscale.com/control/controlhttp+
-        github.com/coder/websocket/internal/errd                     from github.com/coder/websocket
-        github.com/coder/websocket/internal/util                     from github.com/coder/websocket
-        github.com/coder/websocket/internal/xsync                    from github.com/coder/websocket
    L    github.com/coreos/go-iptables/iptables                       from tailscale.com/util/linuxfw
   LD 💣 github.com/creack/pty                                        from tailscale.com/ssh/tailssh
    W 💣 github.com/dblohm7/wingoes                                   from github.com/dblohm7/wingoes/com+
@@ -249,6 +245,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/control/controlbase                            from tailscale.com/control/controlhttp+
         tailscale.com/control/controlclient                          from tailscale.com/cmd/tailscaled+
         tailscale.com/control/controlhttp                            from tailscale.com/control/controlclient
+        tailscale.com/control/controlhttp/controlhttpcommon          from tailscale.com/control/controlhttp
         tailscale.com/control/controlknobs                           from tailscale.com/control/controlclient+
         tailscale.com/derp                                           from tailscale.com/derp/derphttp+
         tailscale.com/derp/derphttp                                  from tailscale.com/cmd/tailscaled+
@@ -327,7 +324,6 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/net/tsdial                                     from tailscale.com/cmd/tailscaled+
      💣 tailscale.com/net/tshttpproxy                                from tailscale.com/clientupdate/distsign+
         tailscale.com/net/tstun                                      from tailscale.com/cmd/tailscaled+
-        tailscale.com/net/wsconn                                     from tailscale.com/control/controlhttp+
         tailscale.com/omit                                           from tailscale.com/ipn/conffile
         tailscale.com/paths                                          from tailscale.com/client/tailscale+
      💣 tailscale.com/portlist                                       from tailscale.com/ipn/ipnlocal
@@ -364,6 +360,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/types/persist                                  from tailscale.com/control/controlclient+
         tailscale.com/types/preftype                                 from tailscale.com/ipn+
         tailscale.com/types/ptr                                      from tailscale.com/control/controlclient+
+        tailscale.com/types/result                                   from tailscale.com/util/lineiter
         tailscale.com/types/structs                                  from tailscale.com/control/controlclient+
         tailscale.com/types/tkatype                                  from tailscale.com/tka+
         tailscale.com/types/views                                    from tailscale.com/ipn/ipnlocal+
@@ -381,7 +378,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
      💣 tailscale.com/util/hashx                                     from tailscale.com/util/deephash
         tailscale.com/util/httphdr                                   from tailscale.com/ipn/ipnlocal+
         tailscale.com/util/httpm                                     from tailscale.com/client/tailscale+
-        tailscale.com/util/lineread                                  from tailscale.com/hostinfo+
+        tailscale.com/util/lineiter                                  from tailscale.com/hostinfo+
    L    tailscale.com/util/linuxfw                                   from tailscale.com/net/netns+
         tailscale.com/util/mak                                       from tailscale.com/control/controlclient+
         tailscale.com/util/multierr                                  from tailscale.com/cmd/tailscaled+

cmd/tailscaled/deps_test.go

@@ -0,0 +1,30 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package main
+
+import (
+	"testing"
+
+	"tailscale.com/tstest/deptest"
+)
+
+func TestOmitSSH(t *testing.T) {
+	const msg = "unexpected with ts_omit_ssh"
+	deptest.DepChecker{
+		GOOS:   "linux",
+		GOARCH: "amd64",
+		Tags:   "ts_omit_ssh",
+		BadDeps: map[string]string{
+			"tailscale.com/ssh/tailssh":            msg,
+			"golang.org/x/crypto/ssh":              msg,
+			"tailscale.com/sessionrecording":       msg,
+			"github.com/anmitsu/go-shlex":          msg,
+			"github.com/creack/pty":                msg,
+			"github.com/kr/fs":                     msg,
+			"github.com/pkg/sftp":                  msg,
+			"github.com/u-root/u-root/pkg/termios": msg,
+			"tempfork/gliderlabs/ssh":              msg,
+		},
+	}.Check(t)
+}

cmd/tailscaled/ssh.go

@@ -1,7 +1,7 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-//go:build linux || darwin || freebsd || openbsd
+//go:build (linux || darwin || freebsd || openbsd) && !ts_omit_ssh
 
 package main
 

cmd/tsconnect/wasm/wasm_js.go

@@ -272,8 +272,8 @@ func (i *jsIPN) run(jsCallbacks js.Value) {
 						name = p.Hostinfo().Hostname()
 					}
 					addrs := make([]string, p.Addresses().Len())
-					for i := range p.Addresses().Len() {
-						addrs[i] = p.Addresses().At(i).Addr().String()
+					for i, ap := range p.Addresses().All() {
+						addrs[i] = ap.Addr().String()
 					}
 					return jsNetMapPeerNode{
 						jsNetMapNode: jsNetMapNode{
@@ -589,8 +589,8 @@ func mapSlice[T any, M any](a []T, f func(T) M) []M {
 
 func mapSliceView[T any, M any](a views.Slice[T], f func(T) M) []M {
 	n := make([]M, a.Len())
-	for i := range a.Len() {
-		n[i] = f(a.At(i))
+	for i, v := range a.All() {
+		n[i] = f(v)
 	}
 	return n
 }

control/controlclient/noise.go

@@ -17,7 +17,6 @@ import (
 
 	"golang.org/x/net/http2"
 	"tailscale.com/control/controlhttp"
-	"tailscale.com/envknob"
 	"tailscale.com/health"
 	"tailscale.com/internal/noiseconn"
 	"tailscale.com/net/dnscache"
@@ -30,7 +29,6 @@ import (
 	"tailscale.com/util/mak"
 	"tailscale.com/util/multierr"
 	"tailscale.com/util/singleflight"
-	"tailscale.com/util/testenv"
 )
 
 // NoiseClient provides a http.Client to connect to tailcontrol over
@@ -107,11 +105,6 @@ type NoiseOpts struct {
 	DialPlan func() *tailcfg.ControlDialPlan
 }
 
-// controlIsPlaintext is whether we should assume that the controlplane is only accessible
-// over plaintext HTTP (as the first hop, before the ts2021 encryption begins).
-// This is used by some tests which don't have a real TLS certificate.
-var controlIsPlaintext = envknob.RegisterBool("TS_CONTROL_IS_PLAINTEXT_HTTP")
-
 // NewNoiseClient returns a new noiseClient for the provided server and machine key.
 // serverURL is of the form https://<host>:<port> (no trailing slash).
 //
@@ -129,7 +122,7 @@ func NewNoiseClient(opts NoiseOpts) (*NoiseClient, error) {
 		if u.Scheme == "http" {
 			httpPort = port
 			httpsPort = "443"
-			if (testenv.InTest() || controlIsPlaintext()) && (u.Hostname() == "127.0.0.1" || u.Hostname() == "localhost") {
+			if u.Hostname() == "127.0.0.1" || u.Hostname() == "localhost" {
 				httpsPort = ""
 			}
 		} else {

control/controlclient/noise_test.go

@@ -15,7 +15,7 @@ import (
 	"time"
 
 	"golang.org/x/net/http2"
-	"tailscale.com/control/controlhttp"
+	"tailscale.com/control/controlhttp/controlhttpserver"
 	"tailscale.com/internal/noiseconn"
 	"tailscale.com/net/netmon"
 	"tailscale.com/net/tsdial"
@@ -201,7 +201,7 @@ func (up *Upgrader) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return nil
 	}
 
-	cbConn, err := controlhttp.AcceptHTTP(r.Context(), w, r, up.noiseKeyPriv, earlyWriteFn)
+	cbConn, err := controlhttpserver.AcceptHTTP(r.Context(), w, r, up.noiseKeyPriv, earlyWriteFn)
 	if err != nil {
 		up.logf("controlhttp: Accept: %v", err)
 		return

control/controlhttp/client.go

@@ -38,6 +38,7 @@ import (
 	"time"
 
 	"tailscale.com/control/controlbase"
+	"tailscale.com/control/controlhttp/controlhttpcommon"
 	"tailscale.com/envknob"
 	"tailscale.com/health"
 	"tailscale.com/net/dnscache"
@@ -571,9 +572,9 @@ func (a *Dialer) tryURLUpgrade(ctx context.Context, u *url.URL, optAddr netip.Ad
 		Method: "POST",
 		URL:    u,
 		Header: http.Header{
-			"Upgrade":           []string{upgradeHeaderValue},
-			"Connection":        []string{"upgrade"},
-			handshakeHeaderName: []string{base64.StdEncoding.EncodeToString(init)},
+			"Upgrade":                             []string{controlhttpcommon.UpgradeHeaderValue},
+			"Connection":                          []string{"upgrade"},
+			controlhttpcommon.HandshakeHeaderName: []string{base64.StdEncoding.EncodeToString(init)},
 		},
 	}
 	req = req.WithContext(ctx)
@@ -597,7 +598,7 @@ func (a *Dialer) tryURLUpgrade(ctx context.Context, u *url.URL, optAddr netip.Ad
 		return nil, fmt.Errorf("httptrace didn't provide a connection")
 	}
 
-	if next := resp.Header.Get("Upgrade"); next != upgradeHeaderValue {
+	if next := resp.Header.Get("Upgrade"); next != controlhttpcommon.UpgradeHeaderValue {
 		resp.Body.Close()
 		return nil, fmt.Errorf("server switched to unexpected protocol %q", next)
 	}

control/controlhttp/client_js.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/coder/websocket"
 	"tailscale.com/control/controlbase"
+	"tailscale.com/control/controlhttp/controlhttpcommon"
 	"tailscale.com/net/wsconn"
 )
 
@@ -42,11 +43,11 @@ func (d *Dialer) Dial(ctx context.Context) (*ClientConn, error) {
 		// Can't set HTTP headers on the websocket request, so we have to to send
 		// the handshake via an HTTP header.
 		RawQuery: url.Values{
-			handshakeHeaderName: []string{base64.StdEncoding.EncodeToString(init)},
+			controlhttpcommon.HandshakeHeaderName: []string{base64.StdEncoding.EncodeToString(init)},
 		}.Encode(),
 	}
 	wsConn, _, err := websocket.Dial(ctx, wsURL.String(), &websocket.DialOptions{
-		Subprotocols: []string{upgradeHeaderValue},
+		Subprotocols: []string{controlhttpcommon.UpgradeHeaderValue},
 	})
 	if err != nil {
 		return nil, err

control/controlhttp/constants.go

@@ -18,15 +18,6 @@ import (
 )
 
 const (
-	// upgradeHeader is the value of the Upgrade HTTP header used to
-	// indicate the Tailscale control protocol.
-	upgradeHeaderValue = "tailscale-control-protocol"
-
-	// handshakeHeaderName is the HTTP request header that can
-	// optionally contain base64-encoded initial handshake
-	// payload, to save an RTT.
-	handshakeHeaderName = "X-Tailscale-Handshake"
-
 	// serverUpgradePath is where the server-side HTTP handler to
 	// to do the protocol switch is located.
 	serverUpgradePath = "/ts2021"

control/controlhttp/controlhttpcommon/controlhttpcommon.go

@@ -0,0 +1,15 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Package controlhttpcommon contains common constants for used
+// by the controlhttp client and controlhttpserver packages.
+package controlhttpcommon
+
+// UpgradeHeader is the value of the Upgrade HTTP header used to
+// indicate the Tailscale control protocol.
+const UpgradeHeaderValue = "tailscale-control-protocol"
+
+// handshakeHeaderName is the HTTP request header that can
+// optionally contain base64-encoded initial handshake
+// payload, to save an RTT.
+const HandshakeHeaderName = "X-Tailscale-Handshake"

control/controlhttp/controlhttpserver/controlhttpserver.go

@@ -3,7 +3,8 @@
 
 //go:build !ios
 
-package controlhttp
+// Package controlhttpserver contains the HTTP server side of the ts2021 control protocol.
+package controlhttpserver
 
 import (
 	"context"
@@ -18,6 +19,7 @@ import (
 
 	"github.com/coder/websocket"
 	"tailscale.com/control/controlbase"
+	"tailscale.com/control/controlhttp/controlhttpcommon"
 	"tailscale.com/net/netutil"
 	"tailscale.com/net/wsconn"
 	"tailscale.com/types/key"
@@ -45,12 +47,12 @@ func acceptHTTP(ctx context.Context, w http.ResponseWriter, r *http.Request, pri
 	if next == "websocket" {
 		return acceptWebsocket(ctx, w, r, private)
 	}
-	if next != upgradeHeaderValue {
+	if next != controlhttpcommon.UpgradeHeaderValue {
 		http.Error(w, "unknown next protocol", http.StatusBadRequest)
 		return nil, fmt.Errorf("client requested unhandled next protocol %q", next)
 	}
 
-	initB64 := r.Header.Get(handshakeHeaderName)
+	initB64 := r.Header.Get(controlhttpcommon.HandshakeHeaderName)
 	if initB64 == "" {
 		http.Error(w, "missing Tailscale handshake header", http.StatusBadRequest)
 		return nil, errors.New("no tailscale handshake header in HTTP request")
@@ -67,7 +69,7 @@ func acceptHTTP(ctx context.Context, w http.ResponseWriter, r *http.Request, pri
 		return nil, errors.New("can't hijack client connection")
 	}
 
-	w.Header().Set("Upgrade", upgradeHeaderValue)
+	w.Header().Set("Upgrade", controlhttpcommon.UpgradeHeaderValue)
 	w.Header().Set("Connection", "upgrade")
 	w.WriteHeader(http.StatusSwitchingProtocols)
 
@@ -117,7 +119,7 @@ func acceptHTTP(ctx context.Context, w http.ResponseWriter, r *http.Request, pri
 // speak HTTP) to a Tailscale control protocol base transport connection.
 func acceptWebsocket(ctx context.Context, w http.ResponseWriter, r *http.Request, private key.MachinePrivate) (*controlbase.Conn, error) {
 	c, err := websocket.Accept(w, r, &websocket.AcceptOptions{
-		Subprotocols:   []string{upgradeHeaderValue},
+		Subprotocols:   []string{controlhttpcommon.UpgradeHeaderValue},
 		OriginPatterns: []string{"*"},
 		// Disable compression because we transmit Noise messages that are not
 		// compressible.
@@ -129,7 +131,7 @@ func acceptWebsocket(ctx context.Context, w http.ResponseWriter, r *http.Request
 	if err != nil {
 		return nil, fmt.Errorf("Could not accept WebSocket connection %v", err)
 	}
-	if c.Subprotocol() != upgradeHeaderValue {
+	if c.Subprotocol() != controlhttpcommon.UpgradeHeaderValue {
 		c.Close(websocket.StatusPolicyViolation, "client must speak the control subprotocol")
 		return nil, fmt.Errorf("Unexpected subprotocol %q", c.Subprotocol())
 	}
@@ -137,7 +139,7 @@ func acceptWebsocket(ctx context.Context, w http.ResponseWriter, r *http.Request
 		c.Close(websocket.StatusPolicyViolation, "Could not parse parameters")
 		return nil, fmt.Errorf("parse query parameters: %v", err)
 	}
-	initB64 := r.Form.Get(handshakeHeaderName)
+	initB64 := r.Form.Get(controlhttpcommon.HandshakeHeaderName)
 	if initB64 == "" {
 		c.Close(websocket.StatusPolicyViolation, "missing Tailscale handshake parameter")
 		return nil, errors.New("no tailscale handshake parameter in HTTP request")

control/controlhttp/http_test.go

@@ -23,12 +23,15 @@ import (
 	"time"
 
 	"tailscale.com/control/controlbase"
+	"tailscale.com/control/controlhttp/controlhttpcommon"
+	"tailscale.com/control/controlhttp/controlhttpserver"
 	"tailscale.com/net/dnscache"
 	"tailscale.com/net/netmon"
 	"tailscale.com/net/socks5"
 	"tailscale.com/net/tsdial"
 	"tailscale.com/tailcfg"
 	"tailscale.com/tstest"
+	"tailscale.com/tstest/deptest"
 	"tailscale.com/tstime"
 	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
@@ -158,7 +161,7 @@ func testControlHTTP(t *testing.T, param httpTestParam) {
 				return err
 			}
 		}
-		conn, err := AcceptHTTP(context.Background(), w, r, server, earlyWriteFn)
+		conn, err := controlhttpserver.AcceptHTTP(context.Background(), w, r, server, earlyWriteFn)
 		if err != nil {
 			log.Print(err)
 		}
@@ -529,7 +532,7 @@ EKTcWGekdmdDPsHloRNtsiCa697B2O9IFA==
 
 func brokenMITMHandler(clock tstime.Clock) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Upgrade", upgradeHeaderValue)
+		w.Header().Set("Upgrade", controlhttpcommon.UpgradeHeaderValue)
 		w.Header().Set("Connection", "upgrade")
 		w.WriteHeader(http.StatusSwitchingProtocols)
 		w.(http.Flusher).Flush()
@@ -574,7 +577,7 @@ func TestDialPlan(t *testing.T) {
 			close(done)
 		})
 		var handler http.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			conn, err := AcceptHTTP(context.Background(), w, r, server, nil)
+			conn, err := controlhttpserver.AcceptHTTP(context.Background(), w, r, server, nil)
 			if err != nil {
 				log.Print(err)
 			} else {
@@ -816,3 +819,14 @@ func (c *closeTrackConn) Close() error {
 	c.d.noteClose(c)
 	return c.Conn.Close()
 }
+
+func TestDeps(t *testing.T) {
+	deptest.DepChecker{
+		GOOS:   "darwin",
+		GOARCH: "arm64",
+		BadDeps: map[string]string{
+			// Only the controlhttpserver needs WebSockets...
+			"github.com/coder/websocket": "controlhttp client shouldn't need websockets",
+		},
+	}.Check(t)
+}

derp/derphttp/derphttp_client.go

@@ -313,6 +313,9 @@ func (c *Client) preferIPv6() bool {
 var dialWebsocketFunc func(ctx context.Context, urlStr string) (net.Conn, error)
 
 func useWebsockets() bool {
+	if !canWebsockets {
+		return false
+	}
 	if runtime.GOOS == "js" {
 		return true
 	}
@@ -383,7 +386,7 @@ func (c *Client) connect(ctx context.Context, caller string) (client *derp.Clien
 	var node *tailcfg.DERPNode // nil when using c.url to dial
 	var idealNodeInRegion bool
 	switch {
-	case useWebsockets():
+	case canWebsockets && useWebsockets():
 		var urlStr string
 		if c.url != nil {
 			urlStr = c.url.String()

derp/derphttp/derphttp_test.go

@@ -17,7 +17,9 @@ import (
 
 	"tailscale.com/derp"
 	"tailscale.com/net/netmon"
+	"tailscale.com/tstest/deptest"
 	"tailscale.com/types/key"
+	"tailscale.com/util/set"
 )
 
 func TestSendRecv(t *testing.T) {
@@ -485,3 +487,23 @@ func TestProbe(t *testing.T) {
 		}
 	}
 }
+
+func TestDeps(t *testing.T) {
+	deptest.DepChecker{
+		GOOS:   "darwin",
+		GOARCH: "arm64",
+		BadDeps: map[string]string{
+			"github.com/coder/websocket": "shouldn't link websockets except on js/wasm",
+		},
+	}.Check(t)
+
+	deptest.DepChecker{
+		GOOS:   "darwin",
+		GOARCH: "arm64",
+		Tags:   "ts_debug_websockets",
+		WantDeps: set.Of(
+			"github.com/coder/websocket",
+		),
+	}.Check(t)
+
+}

derp/derphttp/websocket.go

@@ -1,7 +1,7 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-//go:build linux || js
+//go:build js || ((linux || darwin) && ts_debug_websockets)
 
 package derphttp
 
@@ -14,6 +14,8 @@ import (
 	"tailscale.com/net/wsconn"
 )
 
+const canWebsockets = true
+
 func init() {
 	dialWebsocketFunc = dialWebsocket
 }

derp/derphttp/websocket_stub.go

@@ -0,0 +1,8 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !(js || ((linux || darwin) && ts_debug_websockets))
+
+package derphttp
+
+const canWebsockets = false

envknob/envknob.go

@@ -411,7 +411,7 @@ func TKASkipSignatureCheck() bool { return Bool("TS_UNSAFE_SKIP_NKS_VERIFICATION
 // Kubernetes Operator components.
 func App() string {
 	a := os.Getenv("TS_INTERNAL_APP")
-	if a == kubetypes.AppConnector || a == kubetypes.AppEgressProxy || a == kubetypes.AppIngressProxy || a == kubetypes.AppIngressResource {
+	if a == kubetypes.AppConnector || a == kubetypes.AppEgressProxy || a == kubetypes.AppIngressProxy || a == kubetypes.AppIngressResource || a == kubetypes.AppProxyGroupEgress || a == kubetypes.AppProxyGroupIngress {
 		return a
 	}
 	return ""

go.mod

@@ -42,7 +42,7 @@ require (
 	github.com/golang/snappy v0.0.4
 	github.com/golangci/golangci-lint v1.57.1
 	github.com/google/go-cmp v0.6.0
-	github.com/google/go-containerregistry v0.18.0
+	github.com/google/go-containerregistry v0.20.2
 	github.com/google/gopacket v1.1.19
 	github.com/google/nftables v0.2.1-0.20240414091927-5e242ec57806
 	github.com/google/uuid v1.6.0
@@ -55,7 +55,7 @@ require (
 	github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86
 	github.com/jsimonetti/rtnetlink v1.4.0
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
-	github.com/klauspost/compress v1.17.4
+	github.com/klauspost/compress v1.17.11
 	github.com/kortschak/wol v0.0.0-20200729010619-da482cc4850a
 	github.com/mattn/go-colorable v0.1.13
 	github.com/mattn/go-isatty v0.0.20
@@ -80,7 +80,7 @@ require (
 	github.com/tailscale/golang-x-crypto v0.0.0-20240604161659-3fde5e568aa4
 	github.com/tailscale/goupnp v1.0.1-0.20210804011211-c64d0f06ea05
 	github.com/tailscale/hujson v0.0.0-20221223112325-20486734a56a
-	github.com/tailscale/mkctr v0.0.0-20240628074852-17ca944da6ba
+	github.com/tailscale/mkctr v0.0.0-20241111153353-1a38f6676f10
 	github.com/tailscale/netlink v1.1.1-0.20240822203006-4d49adab4de7
 	github.com/tailscale/peercred v0.0.0-20240214030740-b535050b2aa4
 	github.com/tailscale/web-client-prebuilt v0.0.0-20240226180453-5db17b287bf1
@@ -100,8 +100,8 @@ require (
 	golang.org/x/mod v0.19.0
 	golang.org/x/net v0.27.0
 	golang.org/x/oauth2 v0.16.0
-	golang.org/x/sync v0.7.0
-	golang.org/x/sys v0.22.0
+	golang.org/x/sync v0.9.0
+	golang.org/x/sys v0.27.0
 	golang.org/x/term v0.22.0
 	golang.org/x/time v0.5.0
 	golang.org/x/tools v0.23.0
@@ -125,7 +125,7 @@ require (
 	github.com/Antonboom/testifylint v1.2.0 // indirect
 	github.com/GaijinEntertainment/go-exhaustruct/v3 v3.2.0 // indirect
 	github.com/Masterminds/sprig v2.22.0+incompatible // indirect
-	github.com/Microsoft/go-winio v0.6.1 // indirect
+	github.com/Microsoft/go-winio v0.6.2 // indirect
 	github.com/OpenPeeDeeP/depguard/v2 v2.2.0 // indirect
 	github.com/alecthomas/go-check-sumtype v0.1.4 // indirect
 	github.com/alexkohler/nakedret/v2 v2.0.4 // indirect
@@ -138,7 +138,7 @@ require (
 	github.com/cyphar/filepath-securejoin v0.2.4 // indirect
 	github.com/dave/astrid v0.0.0-20170323122508-8c2895878b14 // indirect
 	github.com/dave/brenda v1.1.0 // indirect
-	github.com/docker/go-connections v0.4.0 // indirect
+	github.com/docker/go-connections v0.5.0 // indirect
 	github.com/docker/go-units v0.5.0 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/ghostiam/protogetter v0.3.5 // indirect
@@ -160,10 +160,10 @@ require (
 	github.com/ykadowak/zerologlint v0.1.5 // indirect
 	go-simpler.org/musttag v0.9.0 // indirect
 	go-simpler.org/sloglint v0.5.0 // indirect
-	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.47.0 // indirect
-	go.opentelemetry.io/otel v1.22.0 // indirect
-	go.opentelemetry.io/otel/metric v1.22.0 // indirect
-	go.opentelemetry.io/otel/trace v1.22.0 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.57.0 // indirect
+	go.opentelemetry.io/otel v1.32.0 // indirect
+	go.opentelemetry.io/otel/metric v1.32.0 // indirect
+	go.opentelemetry.io/otel/trace v1.32.0 // indirect
 	go.uber.org/automaxprocs v1.5.3 // indirect
 	golang.org/x/xerrors v0.0.0-20240716161551-93cc26a95ae9 // indirect
 )
@@ -220,10 +220,10 @@ require (
 	github.com/daixiang0/gci v0.12.3 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/denis-tingaikin/go-header v0.5.0 // indirect
-	github.com/docker/cli v25.0.0+incompatible // indirect
+	github.com/docker/cli v27.3.1+incompatible // indirect
 	github.com/docker/distribution v2.8.3+incompatible // indirect
-	github.com/docker/docker v26.1.4+incompatible // indirect
-	github.com/docker/docker-credential-helpers v0.8.1 // indirect
+	github.com/docker/docker v27.3.1+incompatible // indirect
+	github.com/docker/docker-credential-helpers v0.8.2 // indirect
 	github.com/emicklei/go-restful/v3 v3.11.2 // indirect
 	github.com/emirpasic/gods v1.18.1 // indirect
 	github.com/ettle/strcase v0.2.0 // indirect
@@ -322,7 +322,7 @@ require (
 	github.com/nunnatsa/ginkgolinter v0.16.1 // indirect
 	github.com/olekukonko/tablewriter v0.0.5 // indirect
 	github.com/opencontainers/go-digest v1.0.0 // indirect
-	github.com/opencontainers/image-spec v1.1.0-rc6 // indirect
+	github.com/opencontainers/image-spec v1.1.0 // indirect
 	github.com/pelletier/go-toml/v2 v2.2.0 // indirect
 	github.com/pierrec/lz4/v4 v4.1.21 // indirect
 	github.com/pjbgf/sha1cd v0.3.0 // indirect
@@ -376,7 +376,7 @@ require (
 	github.com/ultraware/funlen v0.1.0 // indirect
 	github.com/ultraware/whitespace v0.1.0 // indirect
 	github.com/uudashr/gocognit v1.1.2 // indirect
-	github.com/vbatts/tar-split v0.11.5 // indirect
+	github.com/vbatts/tar-split v0.11.6 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
 	github.com/xanzy/ssh-agent v0.3.3 // indirect
 	github.com/yagipy/maintidx v1.0.0 // indirect

go.sum

@@ -79,8 +79,8 @@ github.com/Masterminds/sprig v2.22.0+incompatible/go.mod h1:y6hNFY5UBTIWBxnzTeuN
 github.com/Masterminds/sprig/v3 v3.2.3 h1:eL2fZNezLomi0uOLqjQoN6BfsDD+fyLtgbJMAj9n6YA=
 github.com/Masterminds/sprig/v3 v3.2.3/go.mod h1:rXcFaZ2zZbLRJv/xSysmlgIM1u11eBaRMhvYXJNkGuM=
 github.com/Microsoft/go-winio v0.5.2/go.mod h1:WpS1mjBmmwHBEWmogvA2mj8546UReBk4v8QkMxJ6pZY=
-github.com/Microsoft/go-winio v0.6.1 h1:9/kr64B9VUZrLm5YYwbGtUJnMgqWVOdUAXu6Migciow=
-github.com/Microsoft/go-winio v0.6.1/go.mod h1:LRdKpFKfdobln8UmuiYcKPot9D2v6svN5+sAH+4kjUM=
+github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERoyfY=
+github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
 github.com/OpenPeeDeeP/depguard/v2 v2.2.0 h1:vDfG60vDtIuf0MEOhmLlLLSzqaRM8EMcgJPdp74zmpA=
 github.com/OpenPeeDeeP/depguard/v2 v2.2.0/go.mod h1:CIzddKRvLBC4Au5aYP/i3nyaWQ+ClszLIuVocRiCYFQ=
 github.com/ProtonMail/go-crypto v1.0.0 h1:LRuvITjQWX+WIfr930YHG2HNfjR1uOfyf5vE0kC2U78=
@@ -277,16 +277,16 @@ github.com/distribution/reference v0.6.0 h1:0IXCQ5g4/QMHHkarYzh5l+u8T3t73zM5Qvfr
 github.com/distribution/reference v0.6.0/go.mod h1:BbU0aIcezP1/5jX/8MP0YiH4SdvB5Y4f/wlDRiLyi3E=
 github.com/djherbis/times v1.6.0 h1:w2ctJ92J8fBvWPxugmXIv7Nz7Q3iDMKNx9v5ocVH20c=
 github.com/djherbis/times v1.6.0/go.mod h1:gOHeRAz2h+VJNZ5Gmc/o7iD9k4wW7NMVqieYCY99oc0=
-github.com/docker/cli v25.0.0+incompatible h1:zaimaQdnX7fYWFqzN88exE9LDEvRslexpFowZBX6GoQ=
-github.com/docker/cli v25.0.0+incompatible/go.mod h1:JLrzqnKDaYBop7H2jaqPtU4hHvMKP+vjCwu2uszcLI8=
+github.com/docker/cli v27.3.1+incompatible h1:qEGdFBF3Xu6SCvCYhc7CzaQTlBmqDuzxPDpigSyeKQQ=
+github.com/docker/cli v27.3.1+incompatible/go.mod h1:JLrzqnKDaYBop7H2jaqPtU4hHvMKP+vjCwu2uszcLI8=
 github.com/docker/distribution v2.8.3+incompatible h1:AtKxIZ36LoNK51+Z6RpzLpddBirtxJnzDrHLEKxTAYk=
 github.com/docker/distribution v2.8.3+incompatible/go.mod h1:J2gT2udsDAN96Uj4KfcMRqY0/ypR+oyYUYmja8H+y+w=
-github.com/docker/docker v26.1.4+incompatible h1:vuTpXDuoga+Z38m1OZHzl7NKisKWaWlhjQk7IDPSLsU=
-github.com/docker/docker v26.1.4+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
-github.com/docker/docker-credential-helpers v0.8.1 h1:j/eKUktUltBtMzKqmfLB0PAgqYyMHOp5vfsD1807oKo=
-github.com/docker/docker-credential-helpers v0.8.1/go.mod h1:P3ci7E3lwkZg6XiHdRKft1KckHiO9a2rNtyFbZ/ry9M=
-github.com/docker/go-connections v0.4.0 h1:El9xVISelRB7BuFusrZozjnkIM5YnzCViNKohAFqRJQ=
-github.com/docker/go-connections v0.4.0/go.mod h1:Gbd7IOopHjR8Iph03tsViu4nIes5XhDvyHbTtUxmeec=
+github.com/docker/docker v27.3.1+incompatible h1:KttF0XoteNTicmUtBO0L2tP+J7FGRFTjaEF4k6WdhfI=
+github.com/docker/docker v27.3.1+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
+github.com/docker/docker-credential-helpers v0.8.2 h1:bX3YxiGzFP5sOXWc3bTPEXdEaZSeVMrFgOr3T+zrFAo=
+github.com/docker/docker-credential-helpers v0.8.2/go.mod h1:P3ci7E3lwkZg6XiHdRKft1KckHiO9a2rNtyFbZ/ry9M=
+github.com/docker/go-connections v0.5.0 h1:USnMq7hx7gwdVZq1L49hLXaFtUdTADjXGp+uj1Br63c=
+github.com/docker/go-connections v0.5.0/go.mod h1:ov60Kzw0kKElRwhNs9UlUHAE/F9Fe6GLaXnqyDdmEXc=
 github.com/docker/go-units v0.5.0 h1:69rxXcBk27SvSaaxTtLh/8llcHD8vYHT7WSdRZ/jvr4=
 github.com/docker/go-units v0.5.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
 github.com/dsnet/try v0.0.3 h1:ptR59SsrcFUYbT/FhAbKTV6iLkeD6O18qfIWRml2fqI=
@@ -490,8 +490,8 @@ github.com/google/go-cmp v0.5.8/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeN
 github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
-github.com/google/go-containerregistry v0.18.0 h1:ShE7erKNPqRh5ue6Z9DUOlk04WsnFWPO6YGr3OxnfoQ=
-github.com/google/go-containerregistry v0.18.0/go.mod h1:u0qB2l7mvtWVR5kNcbFIhFY1hLbf8eeGapA+vbFDCtQ=
+github.com/google/go-containerregistry v0.20.2 h1:B1wPJ1SN/S7pB+ZAimcciVD+r+yV/l/DSArMxlbwseo=
+github.com/google/go-containerregistry v0.20.2/go.mod h1:z38EKdKh4h7IP2gSfUUqEvalZBqs6AoLeWfUy34nQC8=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/gofuzz v1.2.0 h1:xRy4A+RhZaiKjJ1bPfwQ8sedCA+YS2YcCHW6ec7JMi0=
 github.com/google/gofuzz v1.2.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
@@ -627,8 +627,8 @@ github.com/kisielk/errcheck v1.7.0/go.mod h1:1kLL+jV4e+CFfueBmI1dSK2ADDyQnlrnrY/
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/kkHAIKE/contextcheck v1.1.4 h1:B6zAaLhOEEcjvUgIYEqystmnFk1Oemn8bvJhbt0GMb8=
 github.com/kkHAIKE/contextcheck v1.1.4/go.mod h1:1+i/gWqokIa+dm31mqGLZhZJ7Uh44DJGZVmr6QRBNJg=
-github.com/klauspost/compress v1.17.4 h1:Ej5ixsIri7BrIjBkRZLTo6ghwrEtHFk7ijlczPW4fZ4=
-github.com/klauspost/compress v1.17.4/go.mod h1:/dCuZOvVtNoHsyb+cuJD3itjs3NbnF6KH9zAO4BDxPM=
+github.com/klauspost/compress v1.17.11 h1:In6xLpyWOi1+C7tXUUWv2ot1QvBjxevKAaI6IXrJmUc=
+github.com/klauspost/compress v1.17.11/go.mod h1:pMDklpSncoRMuLFrf1W9Ss9KT+0rH90U12bZKk7uwG0=
 github.com/klauspost/pgzip v1.2.6 h1:8RXeL5crjEUFnR2/Sn6GJNWtSQ3Dk8pq4CL3jvdDyjU=
 github.com/klauspost/pgzip v1.2.6/go.mod h1:Ch1tH69qFZu15pkjo5kYi6mth2Zzwzt50oCQKQE9RUs=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
@@ -749,8 +749,8 @@ github.com/onsi/gomega v1.33.1 h1:dsYjIxxSR755MDmKVsaFQTE22ChNBcuuTWgkUDSubOk=
 github.com/onsi/gomega v1.33.1/go.mod h1:U4R44UsT+9eLIaYRB2a5qajjtQYn0hauxvRm16AVYg0=
 github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
 github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
-github.com/opencontainers/image-spec v1.1.0-rc6 h1:XDqvyKsJEbRtATzkgItUqBA7QHk58yxX1Ov9HERHNqU=
-github.com/opencontainers/image-spec v1.1.0-rc6/go.mod h1:W4s4sFTMaBeK1BQLXbG4AdM2szdn85PY75RI83NrTrM=
+github.com/opencontainers/image-spec v1.1.0 h1:8SG7/vwALn54lVB/0yZ/MMwhFrPYtpEHQb2IpWsCzug=
+github.com/opencontainers/image-spec v1.1.0/go.mod h1:W4s4sFTMaBeK1BQLXbG4AdM2szdn85PY75RI83NrTrM=
 github.com/otiai10/copy v1.2.0/go.mod h1:rrF5dJ5F0t/EWSYODDu4j9/vEeYHMkc8jt0zJChqQWw=
 github.com/otiai10/copy v1.14.0 h1:dCI/t1iTdYGtkvCuBG2BgR6KZa83PTclw4U5n2wAllU=
 github.com/otiai10/copy v1.14.0/go.mod h1:ECfuL02W+/FkTWZWgQqXPWZgW9oeKCSQ5qVfSc4qc4w=
@@ -931,8 +931,8 @@ github.com/tailscale/goupnp v1.0.1-0.20210804011211-c64d0f06ea05 h1:4chzWmimtJPx
 github.com/tailscale/goupnp v1.0.1-0.20210804011211-c64d0f06ea05/go.mod h1:PdCqy9JzfWMJf1H5UJW2ip33/d4YkoKN0r67yKH1mG8=
 github.com/tailscale/hujson v0.0.0-20221223112325-20486734a56a h1:SJy1Pu0eH1C29XwJucQo73FrleVK6t4kYz4NVhp34Yw=
 github.com/tailscale/hujson v0.0.0-20221223112325-20486734a56a/go.mod h1:DFSS3NAGHthKo1gTlmEcSBiZrRJXi28rLNd/1udP1c8=
-github.com/tailscale/mkctr v0.0.0-20240628074852-17ca944da6ba h1:uNo1VCm/xg4alMkIKo8RWTKNx5y1otfVOcKbp+irkL4=
-github.com/tailscale/mkctr v0.0.0-20240628074852-17ca944da6ba/go.mod h1:DxnqIXBplij66U2ZkL688xy07q97qQ83P+TVueLiHq4=
+github.com/tailscale/mkctr v0.0.0-20241111153353-1a38f6676f10 h1:ZB47BgnHcEHQJODkDubs5ZiNeJxMhcgzefV3lykRwVQ=
+github.com/tailscale/mkctr v0.0.0-20241111153353-1a38f6676f10/go.mod h1:iDx/0Rr9VV/KanSUDpJ6I/ROf0sQ7OqljXc/esl0UIA=
 github.com/tailscale/netlink v1.1.1-0.20240822203006-4d49adab4de7 h1:uFsXVBE9Qr4ZoF094vE6iYTLDl0qCiKzYXlL6UeWObU=
 github.com/tailscale/netlink v1.1.1-0.20240822203006-4d49adab4de7/go.mod h1:NzVQi3Mleb+qzq8VmcWpSkcSYxXIg0DkI6XDzpVkhJ0=
 github.com/tailscale/peercred v0.0.0-20240214030740-b535050b2aa4 h1:Gz0rz40FvFVLTBk/K8UNAenb36EbDSnh+q7Z9ldcC8w=
@@ -981,8 +981,8 @@ github.com/ultraware/whitespace v0.1.0 h1:O1HKYoh0kIeqE8sFqZf1o0qbORXUCOQFrlaQyZ
 github.com/ultraware/whitespace v0.1.0/go.mod h1:/se4r3beMFNmewJ4Xmz0nMQ941GJt+qmSHGP9emHYe0=
 github.com/uudashr/gocognit v1.1.2 h1:l6BAEKJqQH2UpKAPKdMfZf5kE4W/2xk8pfU1OVLvniI=
 github.com/uudashr/gocognit v1.1.2/go.mod h1:aAVdLURqcanke8h3vg35BC++eseDm66Z7KmchI5et4k=
-github.com/vbatts/tar-split v0.11.5 h1:3bHCTIheBm1qFTcgh9oPu+nNBtX+XJIupG/vacinCts=
-github.com/vbatts/tar-split v0.11.5/go.mod h1:yZbwRsSeGjusneWgA781EKej9HF8vme8okylkAeNKLk=
+github.com/vbatts/tar-split v0.11.6 h1:4SjTW5+PU11n6fZenf2IPoV8/tz3AaYHMWjf23envGs=
+github.com/vbatts/tar-split v0.11.6/go.mod h1:dqKNtesIOr2j2Qv3W/cHjnvk9I8+G7oAkFDFN6TCBEI=
 github.com/vishvananda/netns v0.0.0-20200728191858-db3c7e526aae/go.mod h1:DD4vA1DwXk04H54A1oHXtwZmA0grkVMdPxx/VGLCah0=
 github.com/vishvananda/netns v0.0.4 h1:Oeaw1EM2JMxD51g9uhtC0D7erkIjgmj8+JZc26m1YX8=
 github.com/vishvananda/netns v0.0.4/go.mod h1:SpkAiCQRtJ6TvvxPnOSyH3BMl6unz3xZlaprSwhNNJM=
@@ -1022,20 +1022,20 @@ go.opencensus.io v0.22.0/go.mod h1:+kGneAE2xo2IficOXnaByMWTGM9T73dGwxeWcUqIpI8=
 go.opencensus.io v0.22.2/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.3/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
-go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.47.0 h1:sv9kVfal0MK0wBMCOGr+HeJm9v803BkJxGrk2au7j08=
-go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.47.0/go.mod h1:SK2UL73Zy1quvRPonmOmRDiWk1KBV3LyIeeIxcEApWw=
-go.opentelemetry.io/otel v1.22.0 h1:xS7Ku+7yTFvDfDraDIJVpw7XPyuHlB9MCiqqX5mcJ6Y=
-go.opentelemetry.io/otel v1.22.0/go.mod h1:eoV4iAi3Ea8LkAEI9+GFT44O6T/D0GWAVFyZVCC6pMI=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.57.0 h1:DheMAlT6POBP+gh8RUH19EOTnQIor5QE0uSRPtzCpSw=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.57.0/go.mod h1:wZcGmeVO9nzP67aYSLDqXNWK87EZWhi7JWj1v7ZXf94=
+go.opentelemetry.io/otel v1.32.0 h1:WnBN+Xjcteh0zdk01SVqV55d/m62NJLJdIyb4y/WO5U=
+go.opentelemetry.io/otel v1.32.0/go.mod h1:00DCVSB0RQcnzlwyTfqtxSm+DRr9hpYrHjNGiBHVQIg=
 go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.22.0 h1:9M3+rhx7kZCIQQhQRYaZCdNu1V73tm4TvXs2ntl98C4=
 go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.22.0/go.mod h1:noq80iT8rrHP1SfybmPiRGc9dc5M8RPmGvtwo7Oo7tc=
-go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.22.0 h1:FyjCyI9jVEfqhUh2MoSkmolPjfh5fp2hnV0b0irxH4Q=
-go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.22.0/go.mod h1:hYwym2nDEeZfG/motx0p7L7J1N1vyzIThemQsb4g2qY=
-go.opentelemetry.io/otel/metric v1.22.0 h1:lypMQnGyJYeuYPhOM/bgjbFM6WE44W1/T45er4d8Hhg=
-go.opentelemetry.io/otel/metric v1.22.0/go.mod h1:evJGjVpZv0mQ5QBRJoBF64yMuOf4xCWdXjK8pzFvliY=
-go.opentelemetry.io/otel/sdk v1.22.0 h1:6coWHw9xw7EfClIC/+O31R8IY3/+EiRFHevmHafB2Gw=
-go.opentelemetry.io/otel/sdk v1.22.0/go.mod h1:iu7luyVGYovrRpe2fmj3CVKouQNdTOkxtLzPvPz1DOc=
-go.opentelemetry.io/otel/trace v1.22.0 h1:Hg6pPujv0XG9QaVbGOBVHunyuLcCC3jN7WEhPx83XD0=
-go.opentelemetry.io/otel/trace v1.22.0/go.mod h1:RbbHXVqKES9QhzZq/fE5UnOSILqRt40a21sPw2He1xo=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.28.0 h1:j9+03ymgYhPKmeXGk5Zu+cIZOlVzd9Zv7QIiyItjFBU=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.28.0/go.mod h1:Y5+XiUG4Emn1hTfciPzGPJaSI+RpDts6BnCIir0SLqk=
+go.opentelemetry.io/otel/metric v1.32.0 h1:xV2umtmNcThh2/a/aCP+h64Xx5wsj8qqnkYZktzNa0M=
+go.opentelemetry.io/otel/metric v1.32.0/go.mod h1:jH7CIbbK6SH2V2wE16W05BHCtIDzauciCRLoc/SyMv8=
+go.opentelemetry.io/otel/sdk v1.28.0 h1:b9d7hIry8yZsgtbmM0DKyPWMMUMlK9NEKuIG4aBqWyE=
+go.opentelemetry.io/otel/sdk v1.28.0/go.mod h1:oYj7ClPUA7Iw3m+r7GeEjz0qckQRJK2B8zjcZEfu7Pg=
+go.opentelemetry.io/otel/trace v1.32.0 h1:WIC9mYrXf8TmY/EXuULKc8hR17vE+Hjv2cssQDe03fM=
+go.opentelemetry.io/otel/trace v1.32.0/go.mod h1:+i4rkvCraA+tG6AzwloGaCtkx53Fa+L+V8e9a7YvhT8=
 go.opentelemetry.io/proto/otlp v1.0.0 h1:T0TX0tmXU8a3CbNXzEKGeU5mIVOdf0oykP+u2lIVU/I=
 go.opentelemetry.io/proto/otlp v1.0.0/go.mod h1:Sy6pihPLfYHkr3NkUbEhGHFhINUSI/v80hjKIs5JXpM=
 go.uber.org/automaxprocs v1.5.3 h1:kWazyxZUrS3Gs4qUpbwo5kEIMGe/DAvi5Z4tl2NW4j8=
@@ -1176,8 +1176,8 @@ golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
-golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sync v0.9.0 h1:fEo0HyrW1GIgZdpbhCRO0PkJajUS5H9IFUztCgEo2jQ=
+golang.org/x/sync v0.9.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -1239,8 +1239,8 @@ golang.org/x/sys v0.4.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.4.1-0.20230131160137-e7d7f63158de/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
-golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.27.0 h1:wBqf8DvsY9Y/2P8gAfPDEYNuS30J4lPHJxXSb/nJZ+s=
+golang.org/x/sys v0.27.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/term v0.1.0/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=

go.toolchain.rev

@@ -1 +1 @@
-bf15628b759344c6fc7763795a405ba65b8be5d7
+96578f73d04e1a231fa2a495ad3fa97747785bc6

hostinfo/hostinfo.go

@@ -25,7 +25,7 @@ import (
 	"tailscale.com/types/ptr"
 	"tailscale.com/util/cloudenv"
 	"tailscale.com/util/dnsname"
-	"tailscale.com/util/lineread"
+	"tailscale.com/util/lineiter"
 	"tailscale.com/version"
 	"tailscale.com/version/distro"
 )
@@ -231,12 +231,12 @@ func desktop() (ret opt.Bool) {
 	}
 
 	seenDesktop := false
-	lineread.File("/proc/net/unix", func(line []byte) error {
+	for lr := range lineiter.File("/proc/net/unix") {
+		line, _ := lr.Value()
 		seenDesktop = seenDesktop || mem.Contains(mem.B(line), mem.S(" @/tmp/dbus-"))
 		seenDesktop = seenDesktop || mem.Contains(mem.B(line), mem.S(".X11-unix"))
 		seenDesktop = seenDesktop || mem.Contains(mem.B(line), mem.S("/wayland-1"))
-		return nil
-	})
+	}
 	ret.Set(seenDesktop)
 
 	// Only cache after a minute - compositors might not have started yet.
@@ -305,21 +305,21 @@ func inContainer() opt.Bool {
 		ret.Set(true)
 		return ret
 	}
-	lineread.File("/proc/1/cgroup", func(line []byte) error {
+	for lr := range lineiter.File("/proc/1/cgroup") {
+		line, _ := lr.Value()
 		if mem.Contains(mem.B(line), mem.S("/docker/")) ||
 			mem.Contains(mem.B(line), mem.S("/lxc/")) {
 			ret.Set(true)
-			return io.EOF // arbitrary non-nil error to stop loop
+			break
 		}
-		return nil
-	})
-	lineread.File("/proc/mounts", func(line []byte) error {
+	}
+	for lr := range lineiter.File("/proc/mounts") {
+		line, _ := lr.Value()
 		if mem.Contains(mem.B(line), mem.S("lxcfs /proc/cpuinfo fuse.lxcfs")) {
 			ret.Set(true)
-			return io.EOF
+			break
 		}
-		return nil
-	})
+	}
 	return ret
 }
 

hostinfo/hostinfo_linux.go

@@ -12,7 +12,7 @@ import (
 
 	"golang.org/x/sys/unix"
 	"tailscale.com/types/ptr"
-	"tailscale.com/util/lineread"
+	"tailscale.com/util/lineiter"
 	"tailscale.com/version/distro"
 )
 
@@ -106,15 +106,18 @@ func linuxVersionMeta() (meta versionMeta) {
 	}
 
 	m := map[string]string{}
-	lineread.File(propFile, func(line []byte) error {
+	for lr := range lineiter.File(propFile) {
+		line, err := lr.Value()
+		if err != nil {
+			break
+		}
 		eq := bytes.IndexByte(line, '=')
 		if eq == -1 {
-			return nil
+			continue
 		}
 		k, v := string(line[:eq]), strings.Trim(string(line[eq+1:]), `"'`)
 		m[k] = v
-		return nil
-	})
+	}
 
 	if v := m["VERSION_CODENAME"]; v != "" {
 		meta.DistroCodeName = v

ipn/backend.go

@@ -73,6 +73,15 @@ const (
 	NotifyInitialOutgoingFiles // if set, the first Notify message (sent immediately) will contain the current Taildrop OutgoingFiles
 
 	NotifyInitialHealthState // if set, the first Notify message (sent immediately) will contain the current health.State of the client
+
+	NotifyRateLimitNetmaps // if set, rate limit netmap updates to once every DefaultNetmapRateLimit seconds
+)
+
+const (
+	// This is the minimum time between netmap updates when NotifyRateLimitNetmaps is included in the Notify opts.
+	// 3 seconds should be sufficient to avoid flooding the UI with netmap updates on large/chatty tailnets without
+	// causing noticable issues with the UI being out of date.
+	DefaultNetmapRateLimit = time.Duration(3 * time.Second)
 )
 
 // Notify is a communication from a backend (e.g. tailscaled) to a frontend

ipn/ipnlocal/c2n.go

@@ -350,6 +350,8 @@ func handleC2NPostureIdentityGet(b *LocalBackend, w http.ResponseWriter, r *http
 		res.PostureDisabled = true
 	}
 
+	b.logf("c2n: posture identity disabled=%v reported %d serials %d hwaddrs", res.PostureDisabled, len(res.SerialNumbers), len(res.IfaceHardwareAddrs))
+
 	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(res)
 }

ipn/ipnlocal/drive.go

@@ -354,9 +354,8 @@ func (b *LocalBackend) driveRemotesFromPeers(nm *netmap.NetworkMap) []*drive.Rem
 
 				// Check that the peer is allowed to share with us.
 				addresses := peer.Addresses()
-				for i := range addresses.Len() {
-					addr := addresses.At(i)
-					capsMap := b.PeerCaps(addr.Addr())
+				for _, p := range addresses.All() {
+					capsMap := b.PeerCaps(p.Addr())
 					if capsMap.HasCapability(tailcfg.PeerCapabilityTaildriveSharer) {
 						return true
 					}

ipn/ipnlocal/local.go

@@ -82,6 +82,7 @@ import (
 	"tailscale.com/tka"
 	"tailscale.com/tsd"
 	"tailscale.com/tstime"
+	"tailscale.com/tstime/rate"
 	"tailscale.com/types/appctype"
 	"tailscale.com/types/dnstype"
 	"tailscale.com/types/empty"
@@ -370,6 +371,16 @@ type LocalBackend struct {
 	// backend is healthy and captive portal detection is not required
 	// (sending false).
 	needsCaptiveDetection chan bool
+
+	// netmapRateLimiter rate limits netmap updates to to the IPN bus.
+	// It should be nil if the ipn bus options do not include the rate limiting flag.
+	// It is automatically created via setNetmapRateLimit.
+	netmapRateLimiter *rate.Limiter
+
+	// deferredNetmapCancel is used to cancel deferred netmap updates which
+	// were initially blocked due to rate limiting.  We always attempt to send the latest
+	// netmap once the rate limiter allows it, discarding any pending netmaps.
+	deferredNetmapCancel context.CancelFunc
 }
 
 // HealthTracker returns the health tracker for the backend.
@@ -475,6 +486,7 @@ func NewLocalBackend(logf logger.Logf, logID logid.PublicID, sys *tsd.System, lo
 		captiveCtx:            captiveCtx,
 		captiveCancel:         nil, // so that we start checkCaptivePortalLoop when Running
 		needsCaptiveDetection: make(chan bool),
+		deferredNetmapCancel:  nil,
 	}
 	mConn.SetNetInfoCallback(b.setNetInfo)
 
@@ -800,6 +812,19 @@ func (b *LocalBackend) pauseOrResumeControlClientLocked() {
 	b.cc.SetPaused((b.state == ipn.Stopped && b.netMap != nil) || (!networkUp && !testenv.InTest() && !assumeNetworkUpdateForTest()))
 }
 
+// DisconnectControl shuts down control client. This can be run before node shutdown to force control to consider this ndoe
+// inactive. This can be used to ensure that nodes that are HA subnet router or app connector replicas are shutting
+// down, clients switch over to other replicas whilst the existing connections are kept alive for some period of time.
+func (b *LocalBackend) DisconnectControl() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	cc := b.resetControlClientLocked()
+	if cc == nil {
+		return
+	}
+	cc.Shutdown()
+}
+
 // captivePortalDetectionInterval is the duration to wait in an unhealthy state with connectivity broken
 // before running captive portal detection.
 const captivePortalDetectionInterval = 2 * time.Second
@@ -952,6 +977,11 @@ func (b *LocalBackend) Shutdown() {
 	if b.notifyCancel != nil {
 		b.notifyCancel()
 	}
+
+	if b.deferredNetmapCancel != nil {
+		b.deferredNetmapCancel()
+	}
+
 	b.mu.Unlock()
 	b.webClientShutdown()
 
@@ -1578,8 +1608,7 @@ func (b *LocalBackend) SetControlClientStatus(c controlclient.Client, st control
 
 		// Update the DERP map in the health package, which uses it for health notifications
 		b.health.SetDERPMap(st.NetMap.DERPMap)
-
-		b.send(ipn.Notify{NetMap: st.NetMap})
+		b.sendNetmap(st.NetMap)
 	}
 	if st.URL != "" {
 		b.logf("Received auth URL: %.20v...", st.URL)
@@ -1664,20 +1693,91 @@ func applySysPolicy(prefs *ipn.Prefs) (anyChange bool) {
 	return anyChange
 }
 
+// setNetmapRateLimit Sets the minimum interval between netmap updates on the IPN Bus (in seconds)
+// If interval is 0 or negative, the rate limiter is disabled.  Netmap rate limiting is
+// disabled by default
+// b.mu must be held
+func (b *LocalBackend) setNetmapRateLimit(interval time.Duration) {
+	if interval > 0 {
+		b.netmapRateLimiter = rate.NewLimiter(rate.Every(interval), 1)
+	} else {
+		b.netmapRateLimiter = nil
+	}
+}
+
+// sendNetmap sends a netmap update to the IPN bus respecting the rate limiter.  This function
+// should be used for all netmap updates on the IPN bus unless there is some critical reason that
+// a netmap update be sent immediately.
+//
+// A non-nil channel will be returned if the netmap update was deferred due to rate limiting.  The channel will be closed
+// when the netmap update is handled.  true or false will be sent to the channel to indicate whether
+// or not the netmap was sent or cancelled respectively.  A nil return value indicates that the netmap
+// was sent immediately.  The returned value is primarily useful for testing and you can safely ignore
+// it and just call this method at will.
+func (b *LocalBackend) sendNetmap(nm *netmap.NetworkMap) chan bool {
+	notify := ipn.Notify{NetMap: nm}
+
+	b.mu.Lock()
+
+	// Cancel all pending netmap updates, they're stale and we have something newer
+	if b.deferredNetmapCancel != nil {
+		b.deferredNetmapCancel()
+	}
+
+	// No rate limiter?  Send it.
+	// Rate limiter allows the send?  Send it.
+	if b.netmapRateLimiter == nil || b.netmapRateLimiter.Allow() {
+		b.mu.Unlock()
+		b.send(notify)
+		return nil
+	}
+
+	// We're rate limited.  Defer the netmap update
+	var ctx context.Context
+	ctx, cancel := context.WithCancel(b.ctx)
+	b.deferredNetmapCancel = cancel
+	// The rate limiter is set to Limit() events per second.  Convert that back to
+	// the time interval we need to wait
+	delay := b.netmapRateLimiter.Delay()
+	b.mu.Unlock()
+
+	c := make(chan bool)
+
+	// Send the netmap update once the rate limiter allows it
+	go func() {
+		select {
+		case <-time.After(delay):
+			b.send(notify)
+			c <- true
+		case <-ctx.Done():
+			c <- false
+		}
+		close(c)
+	}()
+	return c
+}
+
 var _ controlclient.NetmapDeltaUpdater = (*LocalBackend)(nil)
 
-// UpdateNetmapDelta implements controlclient.NetmapDeltaUpdater.
 func (b *LocalBackend) UpdateNetmapDelta(muts []netmap.NodeMutation) (handled bool) {
 	if !b.MagicConn().UpdateNetmapDelta(muts) {
 		return false
 	}
 
-	var notify *ipn.Notify // non-nil if we need to send a Notify
+	// Will be sent if non nil
+	var netmap *netmap.NetworkMap
+	// Will send an empty notify if true and netmap is nil (for tests - see below)
+	var sendEmpty = false
+
 	defer func() {
-		if notify != nil {
+		if netmap != nil {
+			b.sendNetmap(netmap)
+		} else if sendEmpty {
+			notify := new(ipn.Notify)
 			b.send(*notify)
 		}
 	}()
+
 	unlock := b.lockAndGetUnlock()
 	defer unlock()
 	if !b.updateNetmapDeltaLocked(muts) {
@@ -1699,13 +1799,14 @@ func (b *LocalBackend) UpdateNetmapDelta(muts []netmap.NodeMutation) (handled bo
 		slices.SortFunc(nm.Peers, func(a, b tailcfg.NodeView) int {
 			return cmp.Compare(a.ID(), b.ID())
 		})
-		notify = &ipn.Notify{NetMap: nm}
+		netmap = nm
 	} else if testenv.InTest() {
 		// In tests, send an empty Notify as a wake-up so end-to-end
 		// integration tests in another repo can check on the status of
 		// LocalBackend after processing deltas.
-		notify = new(ipn.Notify)
+		sendEmpty = true
 	}
+
 	return true
 }
 
@@ -1798,8 +1899,7 @@ func setExitNodeID(prefs *ipn.Prefs, nm *netmap.NetworkMap, lastSuggestedExitNod
 	}
 
 	for _, peer := range nm.Peers {
-		for i := range peer.Addresses().Len() {
-			addr := peer.Addresses().At(i)
+		for _, addr := range peer.Addresses().All() {
 			if !addr.IsSingleIP() || addr.Addr() != prefs.ExitNodeIP {
 				continue
 			}
@@ -2737,6 +2837,12 @@ func (b *LocalBackend) WatchNotificationsAs(ctx context.Context, actor ipnauth.A
 		cancel:    cancel,
 	}
 	mak.Set(&b.notifyWatchers, sessionID, session)
+	if mask&ipn.NotifyRateLimitNetmaps != 0 {
+		b.setNetmapRateLimit(ipn.DefaultNetmapRateLimit)
+	} else {
+		b.setNetmapRateLimit(0)
+	}
+
 	b.mu.Unlock()
 
 	defer func() {
@@ -4977,6 +5083,9 @@ func (b *LocalBackend) enterStateLockedOnEntry(newState ipn.State, unlock unlock
 		if authURL == "" {
 			systemd.Status("Stopped; run 'tailscale up' to log in")
 		}
+		if b.deferredNetmapCancel != nil {
+			b.deferredNetmapCancel()
+		}
 	case ipn.Starting, ipn.NeedsMachineAuth:
 		b.authReconfig()
 		// Needed so that UpdateEndpoints can run
@@ -4984,12 +5093,14 @@ func (b *LocalBackend) enterStateLockedOnEntry(newState ipn.State, unlock unlock
 	case ipn.Running:
 		var addrStrs []string
 		addrs := netMap.GetAddresses()
-		for i := range addrs.Len() {
-			addrStrs = append(addrStrs, addrs.At(i).Addr().String())
+		for _, p := range addrs.All() {
+			addrStrs = append(addrStrs, p.Addr().String())
 		}
 		systemd.Status("Connected; %s; %s", activeLogin, strings.Join(addrStrs, " "))
 	case ipn.NoState:
-		// Do nothing.
+		if b.deferredNetmapCancel != nil {
+			b.deferredNetmapCancel()
+		}
 	default:
 		b.logf("[unexpected] unknown newState %#v", newState)
 	}
@@ -6076,8 +6187,7 @@ func (b *LocalBackend) SetDNS(ctx context.Context, name, value string) error {
 
 func peerAPIPorts(peer tailcfg.NodeView) (p4, p6 uint16) {
 	svcs := peer.Hostinfo().Services()
-	for i := range svcs.Len() {
-		s := svcs.At(i)
+	for _, s := range svcs.All() {
 		switch s.Proto {
 		case tailcfg.PeerAPI4:
 			p4 = s.Port
@@ -6109,8 +6219,7 @@ func peerAPIBase(nm *netmap.NetworkMap, peer tailcfg.NodeView) string {
 
 	var have4, have6 bool
 	addrs := nm.GetAddresses()
-	for i := range addrs.Len() {
-		a := addrs.At(i)
+	for _, a := range addrs.All() {
 		if !a.IsSingleIP() {
 			continue
 		}
@@ -6132,10 +6241,9 @@ func peerAPIBase(nm *netmap.NetworkMap, peer tailcfg.NodeView) string {
 }
 
 func nodeIP(n tailcfg.NodeView, pred func(netip.Addr) bool) netip.Addr {
-	for i := range n.Addresses().Len() {
-		a := n.Addresses().At(i)
-		if a.IsSingleIP() && pred(a.Addr()) {
-			return a.Addr()
+	for _, pfx := range n.Addresses().All() {
+		if pfx.IsSingleIP() && pred(pfx.Addr()) {
+			return pfx.Addr()
 		}
 	}
 	return netip.Addr{}
@@ -6365,8 +6473,8 @@ func peerCanProxyDNS(p tailcfg.NodeView) bool {
 	// If p.Cap is not populated (e.g. older control server), then do the old
 	// thing of searching through services.
 	services := p.Hostinfo().Services()
-	for i := range services.Len() {
-		if s := services.At(i); s.Proto == tailcfg.PeerAPIDNS && s.Port >= 1 {
+	for _, s := range services.All() {
+		if s.Proto == tailcfg.PeerAPIDNS && s.Port >= 1 {
 			return true
 		}
 	}

ipn/ipnlocal/local_test.go

@@ -572,6 +572,164 @@ func TestSetUseExitNodeEnabled(t *testing.T) {
 	}
 }
 
+func TestNetmapRateLimiting(t *testing.T) {
+	b := new(LocalBackend)
+	var cancel context.CancelFunc
+	b.ctx, cancel = context.WithCancel(context.Background())
+	b.logf = t.Logf
+	b.setNetmapRateLimit(time.Duration(100 * time.Millisecond))
+
+	if b.netmapRateLimiter == nil {
+		t.Fatalf("no netmapRateLimiter")
+	}
+
+	now := time.Now()
+
+	b.netMap = new(netmap.NetworkMap)
+	if g := b.sendNetmap(b.netMap); g != nil {
+		t.Errorf("First should be immediately sent immediately")
+	}
+
+	// We just sent a netmap, so these should all be rate limited. c1 should get cancelled.
+	// c2 should be cancelled.  c3 should be sent after 100ms.
+	c1 := b.sendNetmap(b.netMap)
+	c2 := b.sendNetmap(b.netMap)
+
+	// Let's spam a bunch more we won't track, just for fun
+	for i := 0; i < 10; i++ {
+		if g := b.sendNetmap(b.netMap); g == nil {
+			t.Errorf("should have been deferred")
+		}
+	}
+
+	// This is our last netmap send. It should be deferred and sent after 100ms.
+	c3 := b.sendNetmap(b.netMap)
+
+	// The first onnetmape should be cancelled
+	select {
+	case sent := <-c1:
+		if sent {
+			t.Errorf("Second netmap update was not cacncelled; sent got %v, want %v", sent, false)
+		}
+	}
+
+	// The second netmap should be cancelled
+	select {
+	case sent := <-c2:
+		if sent {
+			t.Errorf("Second netmap update was not cacncelled; got %v, sent want %v", sent, false)
+		}
+	}
+
+	// The last netmap should be sent after about 100ms
+	select {
+	case sent := <-c3:
+		if !sent {
+			t.Errorf("Fourth netmap update was deferred but not sent; sent got %v, want %v", sent, true)
+		}
+	}
+
+	elapsed := time.Since(now)
+	if elapsed < 90*time.Millisecond {
+		t.Errorf("elapsed time %v is too short", elapsed)
+	}
+	if elapsed > 110*time.Millisecond {
+		t.Errorf("elapsed time %v is too long", elapsed)
+	}
+
+	// The rate limiter should be reset at this point and the next netmap should be sent immediately.
+	if g := b.sendNetmap(b.netMap); g != nil {
+		t.Errorf("netmap should be immediately sent immediately")
+	}
+
+	// We're rate limited - becuase we just sent a netmap.
+	// Lower the rate limit and make sure we can send again once the rate limit is up.
+	b.setNetmapRateLimit(time.Duration(10 * time.Millisecond))
+	time.Sleep(12 * time.Millisecond)
+	if g := b.sendNetmap(b.netMap); g != nil {
+		t.Errorf("netmap should be immediately sent immediately")
+	}
+
+	// Check to make sure the cancellation function is properly set and does what it's
+	// supposed to do.
+	c4 := b.sendNetmap(b.netMap)
+	b.deferredNetmapCancel()
+	select {
+	case sent := <-c4:
+		if sent {
+			t.Errorf("Fourth netmap should have been cancelled; sent got %v, want %v", sent, true)
+		}
+	}
+
+	cancel()
+}
+
+func TestNetmapDeferral(t *testing.T) {
+	b := new(LocalBackend)
+	var cancel context.CancelFunc
+	b.ctx, cancel = context.WithCancel(context.Background())
+	b.logf = t.Logf
+
+	w := 40 * time.Millisecond
+
+	// Ensure that a deferred netmap gets sent with the correct delay
+	b.setNetmapRateLimit(time.Duration(w))
+	start := time.Now()
+	b.sendNetmap(b.netMap)
+
+	// Snooze for 20ms
+	time.Sleep(20 * time.Millisecond)
+
+	// This one should be deferred and sent after ~40-20ms
+	c := b.sendNetmap(b.netMap)
+	select {
+	case sent := <-c:
+		if !sent {
+			t.Errorf("Fourth netmap update was deferred but not sent; sent got %v, want %v", sent, true)
+		}
+	}
+
+	slop := 5 * time.Millisecond
+	g := time.Since(start) * time.Millisecond
+
+	// The difference between the elapsed time and the expected time should be within the slop
+	// and our total time should always be slightly greater than the expected time.
+	if w-g > slop || w > g {
+		t.Errorf("elapsed time is too incorrect w:%v g:%v", w, g)
+	}
+
+	cancel()
+}
+
+func TestNetmapNoRateLimiting(t *testing.T) {
+	b := new(LocalBackend)
+	var cancel context.CancelFunc
+	b.ctx, cancel = context.WithCancel(context.Background())
+	b.logf = t.Logf
+
+	// A zero rate limit means send-at-will
+	b.setNetmapRateLimit(0)
+
+	b.netMap = new(netmap.NetworkMap)
+
+	for i := 0; i < 10; i++ {
+		if g := b.sendNetmap(b.netMap); g != nil {
+			t.Errorf("should be immediately sent immediately")
+		}
+	}
+
+	// A negative rate limit also means send-at-will
+	b.setNetmapRateLimit(-1)
+
+	for i := 0; i < 10; i++ {
+		if g := b.sendNetmap(b.netMap); g != nil {
+			t.Errorf("should be immediately sent immediately")
+		}
+	}
+
+	cancel()
+}
+
 func TestFileTargets(t *testing.T) {
 	b := new(LocalBackend)
 	_, err := b.FileTargets()
@@ -3041,12 +3199,10 @@ func deterministicNodeForTest(t testing.TB, want views.Slice[tailcfg.StableNodeI
 		var ret tailcfg.NodeView
 
 		gotIDs := make([]tailcfg.StableNodeID, got.Len())
-		for i := range got.Len() {
-			nv := got.At(i)
+		for i, nv := range got.All() {
 			if !nv.Valid() {
 				t.Fatalf("invalid node at index %v", i)
 			}
-
 			gotIDs[i] = nv.StableID()
 			if nv.StableID() == use {
 				ret = nv

ipn/ipnlocal/network-lock.go

@@ -430,8 +430,7 @@ func (b *LocalBackend) tkaBootstrapFromGenesisLocked(g tkatype.MarshaledAUM, per
 		}
 		bootstrapStateID := fmt.Sprintf("%d:%d", genesis.State.StateID1, genesis.State.StateID2)
 
-		for i := range persist.DisallowedTKAStateIDs().Len() {
-			stateID := persist.DisallowedTKAStateIDs().At(i)
+		for _, stateID := range persist.DisallowedTKAStateIDs().All() {
 			if stateID == bootstrapStateID {
 				return fmt.Errorf("TKA with stateID of %q is disallowed on this node", stateID)
 			}
@@ -572,8 +571,7 @@ func tkaStateFromPeer(p tailcfg.NodeView) ipnstate.TKAPeer {
 		TailscaleIPs: make([]netip.Addr, 0, p.Addresses().Len()),
 		NodeKey:      p.Key(),
 	}
-	for i := range p.Addresses().Len() {
-		addr := p.Addresses().At(i)
+	for _, addr := range p.Addresses().All() {
 		if addr.IsSingleIP() && tsaddr.IsTailscaleIP(addr.Addr()) {
 			fp.TailscaleIPs = append(fp.TailscaleIPs, addr.Addr())
 		}

ipn/ipnlocal/serve.go

@@ -242,8 +242,7 @@ func (b *LocalBackend) updateServeTCPPortNetMapAddrListenersLocked(ports []uint1
 	}
 
 	addrs := nm.GetAddresses()
-	for i := range addrs.Len() {
-		a := addrs.At(i)
+	for _, a := range addrs.All() {
 		for _, p := range ports {
 			addrPort := netip.AddrPortFrom(a.Addr(), p)
 			if _, ok := b.serveListeners[addrPort]; ok {

ipn/ipnlocal/ssh.go

@@ -27,7 +27,7 @@ import (
 	"github.com/tailscale/golang-x-crypto/ssh"
 	"go4.org/mem"
 	"tailscale.com/tailcfg"
-	"tailscale.com/util/lineread"
+	"tailscale.com/util/lineiter"
 	"tailscale.com/util/mak"
 )
 
@@ -80,30 +80,32 @@ func (b *LocalBackend) getSSHUsernames(req *tailcfg.C2NSSHUsernamesRequest) (*ta
 		if err != nil {
 			return nil, err
 		}
-		lineread.Reader(bytes.NewReader(out), func(line []byte) error {
+		for line := range lineiter.Bytes(out) {
 			line = bytes.TrimSpace(line)
 			if len(line) == 0 || line[0] == '_' {
-				return nil
+				continue
 			}
 			add(string(line))
-			return nil
-		})
+		}
 	default:
-		lineread.File("/etc/passwd", func(line []byte) error {
+		for lr := range lineiter.File("/etc/passwd") {
+			line, err := lr.Value()
+			if err != nil {
+				break
+			}
 			line = bytes.TrimSpace(line)
 			if len(line) == 0 || line[0] == '#' || line[0] == '_' {
-				return nil
+				continue
 			}
 			if mem.HasSuffix(mem.B(line), mem.S("/nologin")) ||
 				mem.HasSuffix(mem.B(line), mem.S("/false")) {
-				return nil
+				continue
 			}
 			colon := bytes.IndexByte(line, ':')
 			if colon != -1 {
 				add(string(line[:colon]))
 			}
-			return nil
-		})
+		}
 	}
 	return res, nil
 }

ipn/ipnlocal/web_client.go

@@ -121,8 +121,8 @@ func (b *LocalBackend) updateWebClientListenersLocked() {
 	}
 
 	addrs := b.netMap.GetAddresses()
-	for i := range addrs.Len() {
-		addrPort := netip.AddrPortFrom(addrs.At(i).Addr(), webClientPort)
+	for _, pfx := range addrs.All() {
+		addrPort := netip.AddrPortFrom(pfx.Addr(), webClientPort)
 		if _, ok := b.webClientListeners[addrPort]; ok {
 			continue // already listening
 		}

ipn/localapi/localapi.go

@@ -100,6 +100,7 @@ var handler = map[string]localAPIHandler{
 	"derpmap":                     (*Handler).serveDERPMap,
 	"dev-set-state-store":         (*Handler).serveDevSetStateStore,
 	"dial":                        (*Handler).serveDial,
+	"disconnect-control":          (*Handler).disconnectControl,
 	"dns-osconfig":                (*Handler).serveDNSOSConfig,
 	"dns-query":                   (*Handler).serveDNSQuery,
 	"drive/fileserver-address":    (*Handler).serveDriveServerAddr,
@@ -952,6 +953,22 @@ func (h *Handler) servePprof(w http.ResponseWriter, r *http.Request) {
 	servePprofFunc(w, r)
 }
 
+// disconnectControl is the handler for local API /disconnect-control endpoint that shuts down control client, so that
+// node no longer communicates with control. Doing this makes control consider this node inactive. This can be used
+// before shutting down a replica of HA subnet  router or app connector deployments to ensure that control tells the
+// peers to switch over to another replica whilst still maintaining th existing peer connections.
+func (h *Handler) disconnectControl(w http.ResponseWriter, r *http.Request) {
+	if !h.PermitWrite {
+		http.Error(w, "access denied", http.StatusForbidden)
+		return
+	}
+	if r.Method != httpm.POST {
+		http.Error(w, "use POST", http.StatusMethodNotAllowed)
+		return
+	}
+	h.b.DisconnectControl()
+}
+
 func (h *Handler) reloadConfig(w http.ResponseWriter, r *http.Request) {
 	if !h.PermitWrite {
 		http.Error(w, "access denied", http.StatusForbidden)

k8s-operator/api.md

@@ -21,6 +21,22 @@
 
 
 
+#### AppConnector
+
+
+
+AppConnector defines a Tailscale app connector node configured via Connector.
+
+
+
+_Appears in:_
+- [ConnectorSpec](#connectorspec)
+
+| Field | Description | Default | Validation |
+| --- | --- | --- | --- |
+| `routes` _[Routes](#routes)_ | Routes are optional preconfigured routes for the domains routed via the app connector.<br />If not set, routes for the domains will be discovered dynamically.<br />If set, the app connector will immediately be able to route traffic using the preconfigured routes, but may<br />also dynamically discover other routes.<br />https://tailscale.com/kb/1332/apps-best-practices#preconfiguration |  | Format: cidr <br />MinItems: 1 <br />Type: string <br /> |
+
+
 
 
 #### Connector
@@ -86,8 +102,9 @@ _Appears in:_
 | `tags` _[Tags](#tags)_ | Tags that the Tailscale node will be tagged with.<br />Defaults to [tag:k8s].<br />To autoapprove the subnet routes or exit node defined by a Connector,<br />you can configure Tailscale ACLs to give these tags the necessary<br />permissions.<br />See https://tailscale.com/kb/1337/acl-syntax#autoapprovers.<br />If you specify custom tags here, you must also make the operator an owner of these tags.<br />See  https://tailscale.com/kb/1236/kubernetes-operator/#setting-up-the-kubernetes-operator.<br />Tags cannot be changed once a Connector node has been created.<br />Tag values must be in form ^tag:[a-zA-Z][a-zA-Z0-9-]*$. |  | Pattern: `^tag:[a-zA-Z][a-zA-Z0-9-]*$` <br />Type: string <br /> |
 | `hostname` _[Hostname](#hostname)_ | Hostname is the tailnet hostname that should be assigned to the<br />Connector node. If unset, hostname defaults to <connector<br />name>-connector. Hostname can contain lower case letters, numbers and<br />dashes, it must not start or end with a dash and must be between 2<br />and 63 characters long. |  | Pattern: `^[a-z0-9][a-z0-9-]{0,61}[a-z0-9]$` <br />Type: string <br /> |
 | `proxyClass` _string_ | ProxyClass is the name of the ProxyClass custom resource that<br />contains configuration options that should be applied to the<br />resources created for this Connector. If unset, the operator will<br />create resources with the default configuration. |  |  |
-| `subnetRouter` _[SubnetRouter](#subnetrouter)_ | SubnetRouter defines subnet routes that the Connector node should<br />expose to tailnet. If unset, none are exposed.<br />https://tailscale.com/kb/1019/subnets/ |  |  |
-| `exitNode` _boolean_ | ExitNode defines whether the Connector node should act as a<br />Tailscale exit node. Defaults to false.<br />https://tailscale.com/kb/1103/exit-nodes |  |  |
+| `subnetRouter` _[SubnetRouter](#subnetrouter)_ | SubnetRouter defines subnet routes that the Connector device should<br />expose to tailnet as a Tailscale subnet router.<br />https://tailscale.com/kb/1019/subnets/<br />If this field is unset, the device does not get configured as a Tailscale subnet router.<br />This field is mutually exclusive with the appConnector field. |  |  |
+| `appConnector` _[AppConnector](#appconnector)_ | AppConnector defines whether the Connector device should act as a Tailscale app connector. A Connector that is<br />configured as an app connector cannot be a subnet router or an exit node. If this field is unset, the<br />Connector does not act as an app connector.<br />Note that you will need to manually configure the permissions and the domains for the app connector via the<br />Admin panel.<br />Note also that the main tested and supported use case of this config option is to deploy an app connector on<br />Kubernetes to access SaaS applications available on the public internet. Using the app connector to expose<br />cluster workloads or other internal workloads to tailnet might work, but this is not a use case that we have<br />tested or optimised for.<br />If you are using the app connector to access SaaS applications because you need a predictable egress IP that<br />can be whitelisted, it is also your responsibility to ensure that cluster traffic from the connector flows<br />via that predictable IP, for example by enforcing that cluster egress traffic is routed via an egress NAT<br />device with a static IP address.<br />https://tailscale.com/kb/1281/app-connectors |  |  |
+| `exitNode` _boolean_ | ExitNode defines whether the Connector device should act as a Tailscale exit node. Defaults to false.<br />This field is mutually exclusive with the appConnector field.<br />https://tailscale.com/kb/1103/exit-nodes |  |  |
 
 
 #### ConnectorStatus
@@ -106,6 +123,7 @@ _Appears in:_
 | `conditions` _[Condition](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.3/#condition-v1-meta) array_ | List of status conditions to indicate the status of the Connector.<br />Known condition types are `ConnectorReady`. |  |  |
 | `subnetRoutes` _string_ | SubnetRoutes are the routes currently exposed to tailnet via this<br />Connector instance. |  |  |
 | `isExitNode` _boolean_ | IsExitNode is set to true if the Connector acts as an exit node. |  |  |
+| `isAppConnector` _boolean_ | IsAppConnector is set to true if the Connector acts as an app connector. |  |  |
 | `tailnetIPs` _string array_ | TailnetIPs is the set of tailnet IP addresses (both IPv4 and IPv6)<br />assigned to the Connector node. |  |  |
 | `hostname` _string_ | Hostname is the fully qualified domain name of the Connector node.<br />If MagicDNS is enabled in your tailnet, it is the MagicDNS name of the<br />node. |  |  |
 
@@ -746,6 +764,7 @@ _Validation:_
 - Type: string
 
 _Appears in:_
+- [AppConnector](#appconnector)
 - [SubnetRouter](#subnetrouter)
 
 

k8s-operator/apis/v1alpha1/types_connector.go

@@ -22,6 +22,7 @@ var ConnectorKind = "Connector"
 // +kubebuilder:resource:scope=Cluster,shortName=cn
 // +kubebuilder:printcolumn:name="SubnetRoutes",type="string",JSONPath=`.status.subnetRoutes`,description="CIDR ranges exposed to tailnet by a subnet router defined via this Connector instance."
 // +kubebuilder:printcolumn:name="IsExitNode",type="string",JSONPath=`.status.isExitNode`,description="Whether this Connector instance defines an exit node."
+// +kubebuilder:printcolumn:name="IsAppConnector",type="string",JSONPath=`.status.isAppConnector`,description="Whether this Connector instance is an app connector."
 // +kubebuilder:printcolumn:name="Status",type="string",JSONPath=`.status.conditions[?(@.type == "ConnectorReady")].reason`,description="Status of the deployed Connector resources."
 
 // Connector defines a Tailscale node that will be deployed in the cluster. The
@@ -55,7 +56,8 @@ type ConnectorList struct {
 }
 
 // ConnectorSpec describes a Tailscale node to be deployed in the cluster.
-// +kubebuilder:validation:XValidation:rule="has(self.subnetRouter) || self.exitNode == true",message="A Connector needs to be either an exit node or a subnet router, or both."
+// +kubebuilder:validation:XValidation:rule="has(self.subnetRouter) || (has(self.exitNode) && self.exitNode == true) || has(self.appConnector)",message="A Connector needs to have at least one of exit node, subnet router or app connector configured."
+// +kubebuilder:validation:XValidation:rule="!((has(self.subnetRouter) || (has(self.exitNode)  && self.exitNode == true)) && has(self.appConnector))",message="The appConnector field is mutually exclusive with exitNode and subnetRouter fields."
 type ConnectorSpec struct {
 	// Tags that the Tailscale node will be tagged with.
 	// Defaults to [tag:k8s].
@@ -82,13 +84,31 @@ type ConnectorSpec struct {
 	// create resources with the default configuration.
 	// +optional
 	ProxyClass string `json:"proxyClass,omitempty"`
-	// SubnetRouter defines subnet routes that the Connector node should
-	// expose to tailnet. If unset, none are exposed.
+	// SubnetRouter defines subnet routes that the Connector device should
+	// expose to tailnet as a Tailscale subnet router.
 	// https://tailscale.com/kb/1019/subnets/
+	// If this field is unset, the device does not get configured as a Tailscale subnet router.
+	// This field is mutually exclusive with the appConnector field.
 	// +optional
-	SubnetRouter *SubnetRouter `json:"subnetRouter"`
-	// ExitNode defines whether the Connector node should act as a
-	// Tailscale exit node. Defaults to false.
+	SubnetRouter *SubnetRouter `json:"subnetRouter,omitempty"`
+	// AppConnector defines whether the Connector device should act as a Tailscale app connector. A Connector that is
+	// configured as an app connector cannot be a subnet router or an exit node. If this field is unset, the
+	// Connector does not act as an app connector.
+	// Note that you will need to manually configure the permissions and the domains for the app connector via the
+	// Admin panel.
+	// Note also that the main tested and supported use case of this config option is to deploy an app connector on
+	// Kubernetes to access SaaS applications available on the public internet. Using the app connector to expose
+	// cluster workloads or other internal workloads to tailnet might work, but this is not a use case that we have
+	// tested or optimised for.
+	// If you are using the app connector to access SaaS applications because you need a predictable egress IP that
+	// can be whitelisted, it is also your responsibility to ensure that cluster traffic from the connector flows
+	// via that predictable IP, for example by enforcing that cluster egress traffic is routed via an egress NAT
+	// device with a static IP address.
+	// https://tailscale.com/kb/1281/app-connectors
+	// +optional
+	AppConnector *AppConnector `json:"appConnector,omitempty"`
+	// ExitNode defines whether the Connector device should act as a Tailscale exit node. Defaults to false.
+	// This field is mutually exclusive with the appConnector field.
 	// https://tailscale.com/kb/1103/exit-nodes
 	// +optional
 	ExitNode bool `json:"exitNode"`
@@ -104,6 +124,17 @@ type SubnetRouter struct {
 	AdvertiseRoutes Routes `json:"advertiseRoutes"`
 }
 
+// AppConnector defines a Tailscale app connector node configured via Connector.
+type AppConnector struct {
+	// Routes are optional preconfigured routes for the domains routed via the app connector.
+	// If not set, routes for the domains will be discovered dynamically.
+	// If set, the app connector will immediately be able to route traffic using the preconfigured routes, but may
+	// also dynamically discover other routes.
+	// https://tailscale.com/kb/1332/apps-best-practices#preconfiguration
+	// +optional
+	Routes Routes `json:"routes"`
+}
+
 type Tags []Tag
 
 func (tags Tags) Stringify() []string {
@@ -156,6 +187,9 @@ type ConnectorStatus struct {
 	// IsExitNode is set to true if the Connector acts as an exit node.
 	// +optional
 	IsExitNode bool `json:"isExitNode"`
+	// IsAppConnector is set to true if the Connector acts as an app connector.
+	// +optional
+	IsAppConnector bool `json:"isAppConnector"`
 	// TailnetIPs is the set of tailnet IP addresses (both IPv4 and IPv6)
 	// assigned to the Connector node.
 	// +optional

k8s-operator/apis/v1alpha1/zz_generated.deepcopy.go

@@ -13,6 +13,26 @@ import (
 	"k8s.io/apimachinery/pkg/runtime"
 )
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *AppConnector) DeepCopyInto(out *AppConnector) {
+	*out = *in
+	if in.Routes != nil {
+		in, out := &in.Routes, &out.Routes
+		*out = make(Routes, len(*in))
+		copy(*out, *in)
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new AppConnector.
+func (in *AppConnector) DeepCopy() *AppConnector {
+	if in == nil {
+		return nil
+	}
+	out := new(AppConnector)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *Connector) DeepCopyInto(out *Connector) {
 	*out = *in
@@ -85,6 +105,11 @@ func (in *ConnectorSpec) DeepCopyInto(out *ConnectorSpec) {
 		*out = new(SubnetRouter)
 		(*in).DeepCopyInto(*out)
 	}
+	if in.AppConnector != nil {
+		in, out := &in.AppConnector, &out.AppConnector
+		*out = new(AppConnector)
+		(*in).DeepCopyInto(*out)
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new ConnectorSpec.

k8s-operator/utils.go

@@ -32,9 +32,6 @@ type Records struct {
 // TailscaledConfigFileName returns a tailscaled config file name in
 // format expected by containerboot for the given CapVer.
 func TailscaledConfigFileName(cap tailcfg.CapabilityVersion) string {
-	if cap < 95 {
-		return "tailscaled"
-	}
 	return fmt.Sprintf("cap-%v.hujson", cap)
 }
 

kube/kubetypes/metrics.go

@@ -5,12 +5,14 @@ package kubetypes
 
 const (
 	// Hostinfo App values for the Tailscale Kubernetes Operator components.
-	AppOperator        = "k8s-operator"
-	AppAPIServerProxy  = "k8s-operator-proxy"
-	AppIngressProxy    = "k8s-operator-ingress-proxy"
-	AppIngressResource = "k8s-operator-ingress-resource"
-	AppEgressProxy     = "k8s-operator-egress-proxy"
-	AppConnector       = "k8s-operator-connector-resource"
+	AppOperator          = "k8s-operator"
+	AppAPIServerProxy    = "k8s-operator-proxy"
+	AppIngressProxy      = "k8s-operator-ingress-proxy"
+	AppIngressResource   = "k8s-operator-ingress-resource"
+	AppEgressProxy       = "k8s-operator-egress-proxy"
+	AppConnector         = "k8s-operator-connector-resource"
+	AppProxyGroupEgress  = "k8s-operator-proxygroup-egress"
+	AppProxyGroupIngress = "k8s-operator-proxygroup-ingress"
 
 	// Clientmetrics for Tailscale Kubernetes Operator components
 	MetricIngressProxyCount              = "k8s_ingress_proxies"   // L3
@@ -19,8 +21,10 @@ const (
 	MetricConnectorResourceCount         = "k8s_connector_resources"
 	MetricConnectorWithSubnetRouterCount = "k8s_connector_subnetrouter_resources"
 	MetricConnectorWithExitNodeCount     = "k8s_connector_exitnode_resources"
+	MetricConnectorWithAppConnectorCount = "k8s_connector_appconnector_resources"
 	MetricNameserverCount                = "k8s_nameserver_resources"
 	MetricRecorderCount                  = "k8s_recorder_resources"
 	MetricEgressServiceCount             = "k8s_egress_service_resources"
-	MetricProxyGroupCount                = "k8s_proxygroup_resources"
+	MetricProxyGroupEgressCount          = "k8s_proxygroup_egress_resources"
+	MetricProxyGroupIngressCount         = "k8s_proxygroup_ingress_resources"
 )

licenses/windows.md

@@ -57,8 +57,8 @@ Windows][].  See also the dependencies in the [Tailscale CLI][].
  - [github.com/tailscale/go-winio](https://pkg.go.dev/github.com/tailscale/go-winio) ([MIT](https://github.com/tailscale/go-winio/blob/c4f33415bf55/LICENSE))
  - [github.com/tailscale/hujson](https://pkg.go.dev/github.com/tailscale/hujson) ([BSD-3-Clause](https://github.com/tailscale/hujson/blob/20486734a56a/LICENSE))
  - [github.com/tailscale/netlink](https://pkg.go.dev/github.com/tailscale/netlink) ([Apache-2.0](https://github.com/tailscale/netlink/blob/4d49adab4de7/LICENSE))
- - [github.com/tailscale/walk](https://pkg.go.dev/github.com/tailscale/walk) ([BSD-3-Clause](https://github.com/tailscale/walk/blob/52804fd3056a/LICENSE))
- - [github.com/tailscale/win](https://pkg.go.dev/github.com/tailscale/win) ([BSD-3-Clause](https://github.com/tailscale/win/blob/6580b55d49ca/LICENSE))
+ - [github.com/tailscale/walk](https://pkg.go.dev/github.com/tailscale/walk) ([BSD-3-Clause](https://github.com/tailscale/walk/blob/8865133fd3ef/LICENSE))
+ - [github.com/tailscale/win](https://pkg.go.dev/github.com/tailscale/win) ([BSD-3-Clause](https://github.com/tailscale/win/blob/28f7e73c7afb/LICENSE))
  - [github.com/tailscale/xnet/webdav](https://pkg.go.dev/github.com/tailscale/xnet/webdav) ([BSD-3-Clause](https://github.com/tailscale/xnet/blob/8497ac4dab2e/LICENSE))
  - [github.com/tc-hib/winres](https://pkg.go.dev/github.com/tc-hib/winres) ([0BSD](https://github.com/tc-hib/winres/blob/v0.2.1/LICENSE))
  - [github.com/vishvananda/netns](https://pkg.go.dev/github.com/vishvananda/netns) ([Apache-2.0](https://github.com/vishvananda/netns/blob/v0.0.4/LICENSE))

net/ipset/ipset.go

@@ -82,8 +82,8 @@ func NewContainsIPFunc(addrs views.Slice[netip.Prefix]) func(ip netip.Addr) bool
 		pathForTest("bart")
 		// Built a bart table.
 		t := &bart.Table[struct{}]{}
-		for i := range addrs.Len() {
-			t.Insert(addrs.At(i), struct{}{})
+		for _, p := range addrs.All() {
+			t.Insert(p, struct{}{})
 		}
 		return bartLookup(t)
 	}
@@ -99,8 +99,8 @@ func NewContainsIPFunc(addrs views.Slice[netip.Prefix]) func(ip netip.Addr) bool
 	// General case:
 	pathForTest("ip-map")
 	m := set.Set[netip.Addr]{}
-	for i := range addrs.Len() {
-		m.Add(addrs.At(i).Addr())
+	for _, p := range addrs.All() {
+		m.Add(p.Addr())
 	}
 	return ipInMap(m)
 }

net/netmon/interfaces_android.go

@@ -5,7 +5,6 @@ package netmon
 
 import (
 	"bytes"
-	"errors"
 	"log"
 	"net/netip"
 	"os/exec"
@@ -15,7 +14,7 @@ import (
 	"golang.org/x/sys/unix"
 	"tailscale.com/net/netaddr"
 	"tailscale.com/syncs"
-	"tailscale.com/util/lineread"
+	"tailscale.com/util/lineiter"
 )
 
 var (
@@ -34,11 +33,6 @@ func init() {
 
 var procNetRouteErr atomic.Bool
 
-// errStopReading is a sentinel error value used internally by
-// lineread.File callers to stop reading. It doesn't escape to
-// callers/users.
-var errStopReading = errors.New("stop reading")
-
 /*
 Parse 10.0.0.1 out of:
 
@@ -54,44 +48,42 @@ func likelyHomeRouterIPAndroid() (ret netip.Addr, myIP netip.Addr, ok bool) {
 	}
 	lineNum := 0
 	var f []mem.RO
-	err := lineread.File(procNetRoutePath, func(line []byte) error {
+	for lr := range lineiter.File(procNetRoutePath) {
+		line, err := lr.Value()
+		if err != nil {
+			procNetRouteErr.Store(true)
+			return likelyHomeRouterIP()
+		}
+
 		lineNum++
 		if lineNum == 1 {
 			// Skip header line.
-			return nil
+			continue
 		}
 		if lineNum > maxProcNetRouteRead {
-			return errStopReading
+			break
 		}
 		f = mem.AppendFields(f[:0], mem.B(line))
 		if len(f) < 4 {
-			return nil
+			continue
 		}
 		gwHex, flagsHex := f[2], f[3]
 		flags, err := mem.ParseUint(flagsHex, 16, 16)
 		if err != nil {
-			return nil // ignore error, skip line and keep going
+			continue // ignore error, skip line and keep going
 		}
 		if flags&(unix.RTF_UP|unix.RTF_GATEWAY) != unix.RTF_UP|unix.RTF_GATEWAY {
-			return nil
+			continue
 		}
 		ipu32, err := mem.ParseUint(gwHex, 16, 32)
 		if err != nil {
-			return nil // ignore error, skip line and keep going
+			continue // ignore error, skip line and keep going
 		}
 		ip := netaddr.IPv4(byte(ipu32), byte(ipu32>>8), byte(ipu32>>16), byte(ipu32>>24))
 		if ip.IsPrivate() {
 			ret = ip
-			return errStopReading
+			break
 		}
-		return nil
-	})
-	if errors.Is(err, errStopReading) {
-		err = nil
-	}
-	if err != nil {
-		procNetRouteErr.Store(true)
-		return likelyHomeRouterIP()
 	}
 	if ret.IsValid() {
 		// Try to get the local IP of the interface associated with
@@ -144,23 +136,26 @@ func likelyHomeRouterIPHelper() (ret netip.Addr, _ netip.Addr, ok bool) {
 		return
 	}
 	// Search for line like "default via 10.0.2.2 dev radio0 table 1016 proto static mtu 1500 "
-	lineread.Reader(out, func(line []byte) error {
+	for lr := range lineiter.Reader(out) {
+		line, err := lr.Value()
+		if err != nil {
+			break
+		}
 		const pfx = "default via "
 		if !mem.HasPrefix(mem.B(line), mem.S(pfx)) {
-			return nil
+			continue
 		}
 		line = line[len(pfx):]
 		sp := bytes.IndexByte(line, ' ')
 		if sp == -1 {
-			return nil
+			continue
 		}
 		ipb := line[:sp]
 		if ip, err := netip.ParseAddr(string(ipb)); err == nil && ip.Is4() {
 			ret = ip
 			log.Printf("interfaces: found Android default route %v", ip)
 		}
-		return nil
-	})
+	}
 	cmd.Process.Kill()
 	cmd.Wait()
 	return ret, netip.Addr{}, ret.IsValid()

net/netmon/interfaces_darwin_test.go

@@ -4,14 +4,13 @@
 package netmon
 
 import (
-	"errors"
 	"io"
 	"net/netip"
 	"os/exec"
 	"testing"
 
 	"go4.org/mem"
-	"tailscale.com/util/lineread"
+	"tailscale.com/util/lineiter"
 	"tailscale.com/version"
 )
 
@@ -73,31 +72,34 @@ func likelyHomeRouterIPDarwinExec() (ret netip.Addr, netif string, ok bool) {
 	defer io.Copy(io.Discard, stdout) // clear the pipe to prevent hangs
 
 	var f []mem.RO
-	lineread.Reader(stdout, func(lineb []byte) error {
+	for lr := range lineiter.Reader(stdout) {
+		lineb, err := lr.Value()
+		if err != nil {
+			break
+		}
 		line := mem.B(lineb)
 		if !mem.Contains(line, mem.S("default")) {
-			return nil
+			continue
 		}
 		f = mem.AppendFields(f[:0], line)
 		if len(f) < 4 || !f[0].EqualString("default") {
-			return nil
+			continue
 		}
 		ipm, flagsm, netifm := f[1], f[2], f[3]
 		if !mem.Contains(flagsm, mem.S("G")) {
-			return nil
+			continue
 		}
 		if mem.Contains(flagsm, mem.S("I")) {
-			return nil
+			continue
 		}
 		ip, err := netip.ParseAddr(string(mem.Append(nil, ipm)))
 		if err == nil && ip.IsPrivate() {
 			ret = ip
 			netif = netifm.StringCopy()
 			// We've found what we're looking for.
-			return errStopReadingNetstatTable
+			break
 		}
-		return nil
-	})
+	}
 	return ret, netif, ret.IsValid()
 }
 
@@ -110,5 +112,3 @@ func TestFetchRoutingTable(t *testing.T) {
 		}
 	}
 }
-
-var errStopReadingNetstatTable = errors.New("found private gateway")

net/netmon/interfaces_linux.go

@@ -23,7 +23,7 @@ import (
 	"go4.org/mem"
 	"golang.org/x/sys/unix"
 	"tailscale.com/net/netaddr"
-	"tailscale.com/util/lineread"
+	"tailscale.com/util/lineiter"
 )
 
 func init() {
@@ -32,11 +32,6 @@ func init() {
 
 var procNetRouteErr atomic.Bool
 
-// errStopReading is a sentinel error value used internally by
-// lineread.File callers to stop reading. It doesn't escape to
-// callers/users.
-var errStopReading = errors.New("stop reading")
-
 /*
 Parse 10.0.0.1 out of:
 
@@ -52,44 +47,42 @@ func likelyHomeRouterIPLinux() (ret netip.Addr, myIP netip.Addr, ok bool) {
 	}
 	lineNum := 0
 	var f []mem.RO
-	err := lineread.File(procNetRoutePath, func(line []byte) error {
+	for lr := range lineiter.File(procNetRoutePath) {
+		line, err := lr.Value()
+		if err != nil {
+			procNetRouteErr.Store(true)
+			log.Printf("interfaces: failed to read /proc/net/route: %v", err)
+			return ret, myIP, false
+		}
 		lineNum++
 		if lineNum == 1 {
 			// Skip header line.
-			return nil
+			continue
 		}
 		if lineNum > maxProcNetRouteRead {
-			return errStopReading
+			break
 		}
 		f = mem.AppendFields(f[:0], mem.B(line))
 		if len(f) < 4 {
-			return nil
+			continue
 		}
 		gwHex, flagsHex := f[2], f[3]
 		flags, err := mem.ParseUint(flagsHex, 16, 16)
 		if err != nil {
-			return nil // ignore error, skip line and keep going
+			continue // ignore error, skip line and keep going
 		}
 		if flags&(unix.RTF_UP|unix.RTF_GATEWAY) != unix.RTF_UP|unix.RTF_GATEWAY {
-			return nil
+			continue
 		}
 		ipu32, err := mem.ParseUint(gwHex, 16, 32)
 		if err != nil {
-			return nil // ignore error, skip line and keep going
+			continue // ignore error, skip line and keep going
 		}
 		ip := netaddr.IPv4(byte(ipu32), byte(ipu32>>8), byte(ipu32>>16), byte(ipu32>>24))
 		if ip.IsPrivate() {
 			ret = ip
-			return errStopReading
+			break
 		}
-		return nil
-	})
-	if errors.Is(err, errStopReading) {
-		err = nil
-	}
-	if err != nil {
-		procNetRouteErr.Store(true)
-		log.Printf("interfaces: failed to read /proc/net/route: %v", err)
 	}
 	if ret.IsValid() {
 		// Try to get the local IP of the interface associated with

net/netmon/netmon_linux_test.go

@@ -1,6 +1,8 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
+//go:build linux && !android
+
 package netmon
 
 import (

net/tsaddr/tsaddr.go

@@ -180,8 +180,7 @@ func PrefixIs6(p netip.Prefix) bool { return p.Addr().Is6() }
 // IPv6 /0 route.
 func ContainsExitRoutes(rr views.Slice[netip.Prefix]) bool {
 	var v4, v6 bool
-	for i := range rr.Len() {
-		r := rr.At(i)
+	for _, r := range rr.All() {
 		if r == allIPv4 {
 			v4 = true
 		} else if r == allIPv6 {
@@ -194,8 +193,8 @@ func ContainsExitRoutes(rr views.Slice[netip.Prefix]) bool {
 // ContainsExitRoute reports whether rr contains at least one of IPv4 or
 // IPv6 /0 (exit) routes.
 func ContainsExitRoute(rr views.Slice[netip.Prefix]) bool {
-	for i := range rr.Len() {
-		if rr.At(i).Bits() == 0 {
+	for _, r := range rr.All() {
+		if r.Bits() == 0 {
 			return true
 		}
 	}
@@ -205,8 +204,8 @@ func ContainsExitRoute(rr views.Slice[netip.Prefix]) bool {
 // ContainsNonExitSubnetRoutes reports whether v contains Subnet
 // Routes other than ExitNode Routes.
 func ContainsNonExitSubnetRoutes(rr views.Slice[netip.Prefix]) bool {
-	for i := range rr.Len() {
-		if rr.At(i).Bits() != 0 {
+	for _, r := range rr.All() {
+		if r.Bits() != 0 {
 			return true
 		}
 	}

net/tsdial/dnsmap.go

@@ -42,8 +42,8 @@ func dnsMapFromNetworkMap(nm *netmap.NetworkMap) dnsMap {
 		if dnsname.HasSuffix(nm.Name, suffix) {
 			ret[canonMapKey(dnsname.TrimSuffix(nm.Name, suffix))] = ip
 		}
-		for i := range addrs.Len() {
-			if addrs.At(i).Addr().Is4() {
+		for _, p := range addrs.All() {
+			if p.Addr().Is4() {
 				have4 = true
 			}
 		}
@@ -52,9 +52,8 @@ func dnsMapFromNetworkMap(nm *netmap.NetworkMap) dnsMap {
 		if p.Name() == "" {
 			continue
 		}
-		for i := range p.Addresses().Len() {
-			a := p.Addresses().At(i)
-			ip := a.Addr()
+		for _, pfx := range p.Addresses().All() {
+			ip := pfx.Addr()
 			if ip.Is4() && !have4 {
 				continue
 			}

net/tshttpproxy/tshttpproxy_synology.go

@@ -17,7 +17,7 @@ import (
 	"sync"
 	"time"
 
-	"tailscale.com/util/lineread"
+	"tailscale.com/util/lineiter"
 )
 
 // These vars are overridden for tests.
@@ -76,21 +76,22 @@ func synologyProxiesFromConfig() (*url.URL, *url.URL, error) {
 func parseSynologyConfig(r io.Reader) (*url.URL, *url.URL, error) {
 	cfg := map[string]string{}
 
-	if err := lineread.Reader(r, func(line []byte) error {
+	for lr := range lineiter.Reader(r) {
+		line, err := lr.Value()
+		if err != nil {
+			return nil, nil, err
+		}
 		// accept and skip over empty lines
 		line = bytes.TrimSpace(line)
 		if len(line) == 0 {
-			return nil
+			continue
 		}
 
 		key, value, ok := strings.Cut(string(line), "=")
 		if !ok {
-			return fmt.Errorf("missing \"=\" in proxy.conf line: %q", line)
+			return nil, nil, fmt.Errorf("missing \"=\" in proxy.conf line: %q", line)
 		}
 		cfg[string(key)] = string(value)
-		return nil
-	}); err != nil {
-		return nil, nil, err
 	}
 
 	if cfg["proxy_enabled"] != "yes" {

safeweb/http.go

@@ -71,6 +71,7 @@ package safeweb
 
 import (
 	"cmp"
+	"context"
 	crand "crypto/rand"
 	"fmt"
 	"log"
@@ -416,3 +417,7 @@ func (s *Server) ListenAndServe(addr string) error {
 func (s *Server) Close() error {
 	return s.h.Close()
 }
+
+// Shutdown gracefully shuts down the server without interrupting any active
+// connections. It has the same semantics as[http.Server.Shutdown].
+func (s *Server) Shutdown(ctx context.Context) error { return s.h.Shutdown(ctx) }

ssh/tailssh/tailssh_test.go

@@ -48,7 +48,7 @@ import (
 	"tailscale.com/types/netmap"
 	"tailscale.com/types/ptr"
 	"tailscale.com/util/cibuild"
-	"tailscale.com/util/lineread"
+	"tailscale.com/util/lineiter"
 	"tailscale.com/util/must"
 	"tailscale.com/version/distro"
 	"tailscale.com/wgengine"
@@ -1123,14 +1123,11 @@ func TestSSH(t *testing.T) {
 
 func parseEnv(out []byte) map[string]string {
 	e := map[string]string{}
-	lineread.Reader(bytes.NewReader(out), func(line []byte) error {
-		i := bytes.IndexByte(line, '=')
-		if i == -1 {
-			return nil
+	for line := range lineiter.Bytes(out) {
+		if i := bytes.IndexByte(line, '='); i != -1 {
+			e[string(line[:i])] = string(line[i+1:])
 		}
-		e[string(line[:i])] = string(line[i+1:])
-		return nil
-	})
+	}
 	return e
 }
 

ssh/tailssh/user.go

@@ -6,7 +6,6 @@
 package tailssh
 
 import (
-	"io"
 	"os"
 	"os/exec"
 	"os/user"
@@ -18,7 +17,7 @@ import (
 	"go4.org/mem"
 	"tailscale.com/envknob"
 	"tailscale.com/hostinfo"
-	"tailscale.com/util/lineread"
+	"tailscale.com/util/lineiter"
 	"tailscale.com/util/osuser"
 	"tailscale.com/version/distro"
 )
@@ -110,15 +109,16 @@ func defaultPathForUser(u *user.User) string {
 }
 
 func defaultPathForUserOnNixOS(u *user.User) string {
-	var path string
-	lineread.File("/etc/pam/environment", func(lineb []byte) error {
-		if v := pathFromPAMEnvLine(lineb, u); v != "" {
-			path = v
-			return io.EOF // stop iteration
+	for lr := range lineiter.File("/etc/pam/environment") {
+		lineb, err := lr.Value()
+		if err != nil {
+			return ""
 		}
-		return nil
-	})
-	return path
+		if v := pathFromPAMEnvLine(lineb, u); v != "" {
+			return v
+		}
+	}
+	return ""
 }
 
 func pathFromPAMEnvLine(line []byte, u *user.User) (path string) {

tsnet/tsnet.go

@@ -433,8 +433,7 @@ func (s *Server) TailscaleIPs() (ip4, ip6 netip.Addr) {
 		return
 	}
 	addrs := nm.GetAddresses()
-	for i := range addrs.Len() {
-		addr := addrs.At(i)
+	for _, addr := range addrs.All() {
 		ip := addr.Addr()
 		if ip.Is6() {
 			ip6 = ip

tstest/deptest/deptest.go

@@ -13,14 +13,19 @@ import (
 	"path/filepath"
 	"regexp"
 	"runtime"
+	"slices"
 	"strings"
 	"testing"
+
+	"tailscale.com/util/set"
 )
 
 type DepChecker struct {
-	GOOS    string            // optional
-	GOARCH  string            // optional
-	BadDeps map[string]string // package => why
+	GOOS     string            // optional
+	GOARCH   string            // optional
+	BadDeps  map[string]string // package => why
+	WantDeps set.Set[string]   // packages expected
+	Tags     string            // comma-separated
 }
 
 func (c DepChecker) Check(t *testing.T) {
@@ -29,7 +34,7 @@ func (c DepChecker) Check(t *testing.T) {
 		t.Skip("skipping dep tests on windows hosts")
 	}
 	t.Helper()
-	cmd := exec.Command("go", "list", "-json", ".")
+	cmd := exec.Command("go", "list", "-json", "-tags="+c.Tags, ".")
 	var extraEnv []string
 	if c.GOOS != "" {
 		extraEnv = append(extraEnv, "GOOS="+c.GOOS)
@@ -54,6 +59,11 @@ func (c DepChecker) Check(t *testing.T) {
 			t.Errorf("package %q is not allowed as a dependency (env: %q); reason: %s", dep, extraEnv, why)
 		}
 	}
+	for dep := range c.WantDeps {
+		if !slices.Contains(res.Deps, dep) {
+			t.Errorf("expected package %q to be a dependency (env: %q)", dep, extraEnv)
+		}
+	}
 	t.Logf("got %d dependencies", len(res.Deps))
 }
 

tstest/integration/testcontrol/testcontrol.go

@@ -26,7 +26,7 @@ import (
 	"time"
 
 	"golang.org/x/net/http2"
-	"tailscale.com/control/controlhttp"
+	"tailscale.com/control/controlhttp/controlhttpserver"
 	"tailscale.com/net/netaddr"
 	"tailscale.com/net/tsaddr"
 	"tailscale.com/tailcfg"
@@ -288,7 +288,7 @@ func (s *Server) serveNoiseUpgrade(w http.ResponseWriter, r *http.Request) {
 	s.mu.Lock()
 	noisePrivate := s.noisePrivKey
 	s.mu.Unlock()
-	cc, err := controlhttp.AcceptHTTP(ctx, w, r, noisePrivate, nil)
+	cc, err := controlhttpserver.AcceptHTTP(ctx, w, r, noisePrivate, nil)
 	if err != nil {
 		log.Printf("AcceptHTTP: %v", err)
 		return

tstime/rate/rate.go

@@ -56,6 +56,29 @@ func NewLimiter(r Limit, b int) *Limiter {
 	return &Limiter{limit: r, burst: float64(b)}
 }
 
+// Limit returns the maximum overall event rate.
+func (lim *Limiter) Limit() Limit {
+	return lim.limit
+}
+
+// Delay returns the approximate minimum duration before sufficient tokens
+// will be available to permit another event.
+func (lim *Limiter) Delay() time.Duration {
+	lim.mu.Lock()
+	defer lim.mu.Unlock()
+
+	// Calculate the new number of tokens available due to the passage of time.
+	elapsed := mono.Now().Sub(lim.last)
+	tokens := lim.tokens + float64(lim.limit)*elapsed.Seconds()
+	if tokens > lim.burst {
+		tokens = lim.burst
+	}
+
+	// Calculate the time until the next token is available.
+	wait := time.Duration((1-tokens)/float64(lim.limit)*1e9) * time.Nanosecond
+	return wait
+}
+
 // Allow reports whether an event may happen now.
 func (lim *Limiter) Allow() bool {
 	return lim.allow(mono.Now())

tstime/rate/rate_test.go

@@ -145,6 +145,31 @@ func TestSimultaneousRequests(t *testing.T) {
 	}
 }
 
+func TestDelay(t *testing.T) {
+	lim := NewLimiter(Every(1*time.Second), 1)
+	// We'll allow for 10 ms of slop to avoid flakiness.
+	// w should always be just slightly greater than d
+	slop := int64(10)
+
+	lim.Allow()
+
+	d := lim.Delay().Milliseconds()
+	w := int64(1000)
+
+	if w-d > slop || d > w {
+		t.Errorf("Delay() = %v want 1000", d)
+	}
+
+	time.Sleep(50 * time.Millisecond)
+	w = 950
+	d = lim.Delay().Milliseconds()
+
+	// ~50 milliseconds will have passed,
+	if w-d > slop || d > w {
+		t.Errorf("Delay() = %v want 950", d)
+	}
+}
+
 func BenchmarkAllowN(b *testing.B) {
 	lim := NewLimiter(Every(1*time.Second), 1)
 	now := mono.Now()

tsweb/varz/varz.go

@@ -23,10 +23,16 @@ import (
 	"tailscale.com/version"
 )
 
+// StaticStringVar returns a new expvar.Var that always returns s.
+func StaticStringVar(s string) expvar.Var {
+	var v any = s // box s into an interface just once
+	return expvar.Func(func() any { return v })
+}
+
 func init() {
 	expvar.Publish("process_start_unix_time", expvar.Func(func() any { return timeStart.Unix() }))
-	expvar.Publish("version", expvar.Func(func() any { return version.Long() }))
-	expvar.Publish("go_version", expvar.Func(func() any { return runtime.Version() }))
+	expvar.Publish("version", StaticStringVar(version.Long()))
+	expvar.Publish("go_version", StaticStringVar(runtime.Version()))
 	expvar.Publish("counter_uptime_sec", expvar.Func(func() any { return int64(Uptime().Seconds()) }))
 	expvar.Publish("gauge_goroutines", expvar.Func(func() any { return runtime.NumGoroutine() }))
 }

types/netmap/netmap.go

@@ -279,15 +279,14 @@ func (a *NetworkMap) equalConciseHeader(b *NetworkMap) bool {
 // in nodeConciseEqual in sync.
 func printPeerConcise(buf *strings.Builder, p tailcfg.NodeView) {
 	aip := make([]string, p.AllowedIPs().Len())
-	for i := range aip {
-		a := p.AllowedIPs().At(i)
-		s := strings.TrimSuffix(fmt.Sprint(a), "/32")
+	for i, a := range p.AllowedIPs().All() {
+		s := strings.TrimSuffix(a.String(), "/32")
 		aip[i] = s
 	}
 
-	ep := make([]string, p.Endpoints().Len())
-	for i := range ep {
-		e := p.Endpoints().At(i).String()
+	epStrs := make([]string, p.Endpoints().Len())
+	for i, ep := range p.Endpoints().All() {
+		e := ep.String()
 		// Align vertically on the ':' between IP and port
 		colon := strings.IndexByte(e, ':')
 		spaces := 0
@@ -295,7 +294,7 @@ func printPeerConcise(buf *strings.Builder, p tailcfg.NodeView) {
 			spaces++
 			colon--
 		}
-		ep[i] = fmt.Sprintf("%21v", e+strings.Repeat(" ", spaces))
+		epStrs[i] = fmt.Sprintf("%21v", e+strings.Repeat(" ", spaces))
 	}
 
 	derp := p.DERP()
@@ -316,7 +315,7 @@ func printPeerConcise(buf *strings.Builder, p tailcfg.NodeView) {
 		discoShort,
 		derp,
 		strings.Join(aip, " "),
-		strings.Join(ep, " "))
+		strings.Join(epStrs, " "))
 }
 
 // nodeConciseEqual reports whether a and b are equal for the fields accessed by printPeerConcise.

types/result/result.go

@@ -0,0 +1,49 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Package result contains the Of result type, which is
+// either a value or an error.
+package result
+
+// Of is either a T value or an error.
+//
+// Think of it like Rust or Swift's result types.
+// It's named "Of" because the fully qualified name
+// for callers reads result.Of[T].
+type Of[T any] struct {
+	v   T // valid if Err is nil; invalid if Err is non-nil
+	err error
+}
+
+// Value returns a new result with value v,
+// without an error.
+func Value[T any](v T) Of[T] {
+	return Of[T]{v: v}
+}
+
+// Error returns a new result with error err.
+// If err is nil, the returned result is equivalent
+// to calling Value with T's zero value.
+func Error[T any](err error) Of[T] {
+	return Of[T]{err: err}
+}
+
+// MustValue returns r's result value.
+// It panics if r.Err returns non-nil.
+func (r Of[T]) MustValue() T {
+	if r.err != nil {
+		panic(r.err)
+	}
+	return r.v
+}
+
+// Value returns r's result value and error.
+func (r Of[T]) Value() (T, error) {
+	return r.v, r.err
+}
+
+// Err returns r's error, if any.
+// When r.Err returns nil, it's safe to call r.MustValue without it panicking.
+func (r Of[T]) Err() error {
+	return r.err
+}

util/codegen/codegen.go

@@ -277,11 +277,16 @@ func IsInvalid(t types.Type) bool {
 // It has special handling for some types that contain pointers
 // that we know are free from memory aliasing/mutation concerns.
 func ContainsPointers(typ types.Type) bool {
-	switch typ.String() {
+	s := typ.String()
+	switch s {
 	case "time.Time":
-		// time.Time contains a pointer that does not need copying
+		// time.Time contains a pointer that does not need cloning.
 		return false
-	case "inet.af/netip.Addr", "net/netip.Addr", "net/netip.Prefix", "net/netip.AddrPort":
+	case "inet.af/netip.Addr":
+		return false
+	}
+	if strings.HasPrefix(s, "unique.Handle[") {
+		// unique.Handle contains a pointer that does not need cloning.
 		return false
 	}
 	switch ft := typ.Underlying().(type) {

util/codegen/codegen_test.go

@@ -10,6 +10,8 @@ import (
 	"strings"
 	"sync"
 	"testing"
+	"time"
+	"unique"
 	"unsafe"
 
 	"golang.org/x/exp/constraints"
@@ -84,6 +86,16 @@ type PointerUnionParam[T netip.Prefix | BasicType | IntPtr] struct {
 	V T
 }
 
+type StructWithUniqueHandle struct{ _ unique.Handle[[32]byte] }
+
+type StructWithTime struct{ _ time.Time }
+
+type StructWithNetipTypes struct {
+	_ netip.Addr
+	_ netip.AddrPort
+	_ netip.Prefix
+}
+
 type Interface interface {
 	Method()
 }
@@ -161,6 +173,18 @@ func TestGenericContainsPointers(t *testing.T) {
 			typ:         "PointerUnionParam",
 			wantPointer: true,
 		},
+		{
+			typ:         "StructWithUniqueHandle",
+			wantPointer: false,
+		},
+		{
+			typ:         "StructWithTime",
+			wantPointer: false,
+		},
+		{
+			typ:         "StructWithNetipTypes",
+			wantPointer: false,
+		},
 	}
 
 	for _, tt := range tests {

util/lineiter/lineiter.go

@@ -0,0 +1,72 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Package lineiter iterates over lines in things.
+package lineiter
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"iter"
+	"os"
+
+	"tailscale.com/types/result"
+)
+
+// File returns an iterator that reads lines from the named file.
+//
+// The returned substrings don't include the trailing newline.
+// Lines may be empty.
+func File(name string) iter.Seq[result.Of[[]byte]] {
+	f, err := os.Open(name)
+	return reader(f, f, err)
+}
+
+// Bytes returns an iterator over the lines in bs.
+// The returned substrings don't include the trailing newline.
+// Lines may be empty.
+func Bytes(bs []byte) iter.Seq[[]byte] {
+	return func(yield func([]byte) bool) {
+		for len(bs) > 0 {
+			i := bytes.IndexByte(bs, '\n')
+			if i < 0 {
+				yield(bs)
+				return
+			}
+			if !yield(bs[:i]) {
+				return
+			}
+			bs = bs[i+1:]
+		}
+	}
+}
+
+// Reader returns an iterator over the lines in r.
+//
+// The returned substrings don't include the trailing newline.
+// Lines may be empty.
+func Reader(r io.Reader) iter.Seq[result.Of[[]byte]] {
+	return reader(r, nil, nil)
+}
+
+func reader(r io.Reader, c io.Closer, err error) iter.Seq[result.Of[[]byte]] {
+	return func(yield func(result.Of[[]byte]) bool) {
+		if err != nil {
+			yield(result.Error[[]byte](err))
+			return
+		}
+		if c != nil {
+			defer c.Close()
+		}
+		bs := bufio.NewScanner(r)
+		for bs.Scan() {
+			if !yield(result.Value(bs.Bytes())) {
+				return
+			}
+		}
+		if err := bs.Err(); err != nil {
+			yield(result.Error[[]byte](err))
+		}
+	}
+}

util/lineiter/lineiter_test.go

@@ -0,0 +1,32 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package lineiter
+
+import (
+	"slices"
+	"strings"
+	"testing"
+)
+
+func TestBytesLines(t *testing.T) {
+	var got []string
+	for line := range Bytes([]byte("foo\n\nbar\nbaz")) {
+		got = append(got, string(line))
+	}
+	want := []string{"foo", "", "bar", "baz"}
+	if !slices.Equal(got, want) {
+		t.Errorf("got %q; want %q", got, want)
+	}
+}
+
+func TestReader(t *testing.T) {
+	var got []string
+	for line := range Reader(strings.NewReader("foo\n\nbar\nbaz")) {
+		got = append(got, string(line.MustValue()))
+	}
+	want := []string{"foo", "", "bar", "baz"}
+	if !slices.Equal(got, want) {
+		t.Errorf("got %q; want %q", got, want)
+	}
+}

util/pidowner/pidowner_linux.go

@@ -8,26 +8,26 @@ import (
 	"os"
 	"strings"
 
-	"tailscale.com/util/lineread"
+	"tailscale.com/util/lineiter"
 )
 
 func ownerOfPID(pid int) (userID string, err error) {
 	file := fmt.Sprintf("/proc/%d/status", pid)
-	err = lineread.File(file, func(line []byte) error {
+	for lr := range lineiter.File(file) {
+		line, err := lr.Value()
+		if err != nil {
+			if os.IsNotExist(err) {
+				return "", ErrProcessNotFound
+			}
+			return "", err
+		}
 		if len(line) < 4 || string(line[:4]) != "Uid:" {
-			return nil
+			continue
 		}
 		f := strings.Fields(string(line))
 		if len(f) >= 2 {
 			userID = f[1] // real userid
 		}
-		return nil
-	})
-	if os.IsNotExist(err) {
-		return "", ErrProcessNotFound
-	}
-	if err != nil {
-		return
 	}
 	if userID == "" {
 		return "", fmt.Errorf("missing Uid line in %s", file)

util/set/slice.go

@@ -67,7 +67,7 @@ func (ss *Slice[T]) Add(vs ...T) {
 
 // AddSlice adds all elements in vs to the set.
 func (ss *Slice[T]) AddSlice(vs views.Slice[T]) {
-	for i := range vs.Len() {
-		ss.Add(vs.At(i))
+	for _, v := range vs.All() {
+		ss.Add(v)
 	}
 }

version/distro/distro.go

@@ -6,13 +6,12 @@ package distro
 
 import (
 	"bytes"
-	"io"
 	"os"
 	"runtime"
 	"strconv"
 
 	"tailscale.com/types/lazy"
-	"tailscale.com/util/lineread"
+	"tailscale.com/util/lineiter"
 )
 
 type Distro string
@@ -132,18 +131,19 @@ func DSMVersion() int {
 			return v
 		}
 		// But when run from the command line, we have to read it from the file:
-		lineread.File("/etc/VERSION", func(line []byte) error {
+		for lr := range lineiter.File("/etc/VERSION") {
+			line, err := lr.Value()
+			if err != nil {
+				break // but otherwise ignore
+			}
 			line = bytes.TrimSpace(line)
 			if string(line) == `majorversion="7"` {
-				v = 7
-				return io.EOF
+				return 7
 			}
 			if string(line) == `majorversion="6"` {
-				v = 6
-				return io.EOF
+				return 6
 			}
-			return nil
-		})
-		return v
+		}
+		return 0
 	})
 }

wgengine/magicsock/debughttp.go

@@ -102,8 +102,7 @@ func (c *Conn) ServeHTTPDebug(w http.ResponseWriter, r *http.Request) {
 		sort.Slice(ent, func(i, j int) bool { return ent[i].pub.Less(ent[j].pub) })
 
 		peers := map[key.NodePublic]tailcfg.NodeView{}
-		for i := range c.peers.Len() {
-			p := c.peers.At(i)
+		for _, p := range c.peers.All() {
 			peers[p.Key()] = p
 		}
 

wgengine/magicsock/endpoint.go

@@ -9,6 +9,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
+	"iter"
 	"math"
 	"math/rand/v2"
 	"net"
@@ -1384,20 +1385,18 @@ func (de *endpoint) updateFromNode(n tailcfg.NodeView, heartbeatDisabled bool, p
 }
 
 func (de *endpoint) setEndpointsLocked(eps interface {
-	Len() int
-	At(i int) netip.AddrPort
+	All() iter.Seq2[int, netip.AddrPort]
 }) {
 	for _, st := range de.endpointState {
 		st.index = indexSentinelDeleted // assume deleted until updated in next loop
 	}
 
 	var newIpps []netip.AddrPort
-	for i := range eps.Len() {
+	for i, ipp := range eps.All() {
 		if i > math.MaxInt16 {
 			// Seems unlikely.
 			break
 		}
-		ipp := eps.At(i)
 		if !ipp.IsValid() {
 			de.c.logf("magicsock: bogus netmap endpoint from %v", eps)
 			continue

wgengine/magicsock/magicsock.go

@@ -1120,8 +1120,8 @@ func (c *Conn) determineEndpoints(ctx context.Context) ([]tailcfg.Endpoint, erro
 	// re-run.
 	eps = c.endpointTracker.update(time.Now(), eps)
 
-	for i := range c.staticEndpoints.Len() {
-		addAddr(c.staticEndpoints.At(i), tailcfg.EndpointExplicitConf)
+	for _, ep := range c.staticEndpoints.All() {
+		addAddr(ep, tailcfg.EndpointExplicitConf)
 	}
 
 	if localAddr := c.pconn4.LocalAddr(); localAddr.IP.IsUnspecified() {
@@ -2360,16 +2360,14 @@ func (c *Conn) logEndpointCreated(n tailcfg.NodeView) {
 			fmt.Fprintf(w, "derp=%v%s ", regionID, code)
 		}
 
-		for i := range n.AllowedIPs().Len() {
-			a := n.AllowedIPs().At(i)
+		for _, a := range n.AllowedIPs().All() {
 			if a.IsSingleIP() {
 				fmt.Fprintf(w, "aip=%v ", a.Addr())
 			} else {
 				fmt.Fprintf(w, "aip=%v ", a)
 			}
 		}
-		for i := range n.Endpoints().Len() {
-			ep := n.Endpoints().At(i)
+		for _, ep := range n.Endpoints().All() {
 			fmt.Fprintf(w, "ep=%v ", ep)
 		}
 	}))

wgengine/netstack/netstack.go

@@ -643,13 +643,11 @@ func (ns *Impl) UpdateNetstackIPs(nm *netmap.NetworkMap) {
 	newPfx := make(map[netip.Prefix]bool)
 
 	if selfNode.Valid() {
-		for i := range selfNode.Addresses().Len() {
-			p := selfNode.Addresses().At(i)
+		for _, p := range selfNode.Addresses().All() {
 			newPfx[p] = true
 		}
 		if ns.ProcessSubnets {
-			for i := range selfNode.AllowedIPs().Len() {
-				p := selfNode.AllowedIPs().At(i)
+			for _, p := range selfNode.AllowedIPs().All() {
 				newPfx[p] = true
 			}
 		}

wgengine/pendopen.go

@@ -207,8 +207,7 @@ func (e *userspaceEngine) onOpenTimeout(flow flowtrack.Tuple) {
 	ps, found := e.getPeerStatusLite(n.Key())
 	if !found {
 		onlyZeroRoute := true // whether peerForIP returned n only because its /0 route matched
-		for i := range n.AllowedIPs().Len() {
-			r := n.AllowedIPs().At(i)
+		for _, r := range n.AllowedIPs().All() {
 			if r.Bits() != 0 && r.Contains(flow.DstAddr()) {
 				onlyZeroRoute = false
 				break

wgengine/userspace.go

@@ -852,8 +852,7 @@ func (e *userspaceEngine) updateActivityMapsLocked(trackNodes []key.NodePublic,
 // hasOverlap checks if there is a IPPrefix which is common amongst the two
 // provided slices.
 func hasOverlap(aips, rips views.Slice[netip.Prefix]) bool {
-	for i := range aips.Len() {
-		aip := aips.At(i)
+	for _, aip := range aips.All() {
 		if views.SliceContains(rips, aip) {
 			return true
 		}
@@ -1329,9 +1328,9 @@ func (e *userspaceEngine) mySelfIPMatchingFamily(dst netip.Addr) (src netip.Addr
 	if addrs.Len() == 0 {
 		return zero, errors.New("no self address in netmap")
 	}
-	for i := range addrs.Len() {
-		if a := addrs.At(i); a.IsSingleIP() && a.Addr().BitLen() == dst.BitLen() {
-			return a.Addr(), nil
+	for _, p := range addrs.All() {
+		if p.IsSingleIP() && p.Addr().BitLen() == dst.BitLen() {
+			return p.Addr(), nil
 		}
 	}
 	return zero, errors.New("no self address in netmap matching address family")

wgengine/wgcfg/nmcfg/nmcfg.go

@@ -40,8 +40,7 @@ func cidrIsSubnet(node tailcfg.NodeView, cidr netip.Prefix) bool {
 	if !cidr.IsSingleIP() {
 		return true
 	}
-	for i := range node.Addresses().Len() {
-		selfCIDR := node.Addresses().At(i)
+	for _, selfCIDR := range node.Addresses().All() {
 		if cidr == selfCIDR {
 			return false
 		}
@@ -110,8 +109,7 @@ func WGCfg(nm *netmap.NetworkMap, logf logger.Logf, flags netmap.WGConfigFlags,
 		cpeer.V4MasqAddr = peer.SelfNodeV4MasqAddrForThisPeer()
 		cpeer.V6MasqAddr = peer.SelfNodeV6MasqAddrForThisPeer()
 		cpeer.IsJailed = peer.IsJailed()
-		for i := range peer.AllowedIPs().Len() {
-			allowedIP := peer.AllowedIPs().At(i)
+		for _, allowedIP := range peer.AllowedIPs().All() {
 			if allowedIP.Bits() == 0 && peer.StableID() != exitNode {
 				if didExitNodeWarn {
 					// Don't log about both the IPv4 /0 and IPv6 /0.

words/scales.txt

@@ -391,3 +391,11 @@ godzilla
 sirius
 vector
 cherimoya
+shilling
+kettle
+kitchen
+fahrenheit
+rankine
+piano
+ruler
+scoville