Add additional test cases to verify different base domains produce different shuffle orders

Added two more test cases with the same dataset (region 4) but different base domains to ensure the shuffle is truly deterministic and that different seeds produce different results.

Co-authored-by: kradalby <98431+kradalby@users.noreply.github.com>

.github/workflows/integration-test-template.yml

@@ -62,6 +62,7 @@ jobs:
             '**/flake.lock') }}
           restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
       - name: Run Integration Test
+        if: always() && steps.changed-files.outputs.files == 'true'
         run:
           nix develop --command -- hi run --stats --ts-memory-limit=300 --hs-memory-limit=1500 "^${{ inputs.test }}$" \
           --timeout=120m \

.github/workflows/test-integration.yaml

@@ -24,11 +24,11 @@ jobs:
           - TestACLAutogroupMember
           - TestACLAutogroupTagged
           - TestACLAutogroupSelf
+          - TestACLPolicyPropagationOverTime
           - TestAPIAuthenticationBypass
           - TestAPIAuthenticationBypassCurl
           - TestGRPCAuthenticationBypass
           - TestCLIWithConfigAuthenticationBypass
-          - TestACLPolicyPropagationOverTime
           - TestAuthKeyLogoutAndReloginSameUser
           - TestAuthKeyLogoutAndReloginNewUser
           - TestAuthKeyLogoutAndReloginSameUserExpiredKey

.goreleaser.yml

@@ -8,6 +8,33 @@ before:
 release:
   prerelease: auto
   draft: true
+  header: |
+    ## Upgrade
+
+    Please follow the steps outlined in the [upgrade guide](https://headscale.net/stable/setup/upgrade/) to update your existing Headscale installation.
+
+    **It's best to update from one stable version to the next** (e.g., 0.24.0 → 0.25.1 → 0.26.1) in case you are multiple releases behind. You should always pick the latest available patch release.
+
+    Be sure to check the changelog above for version-specific upgrade instructions and breaking changes.
+
+    ### Backup Your Database
+
+    **Always backup your database before upgrading.** Here's how to backup a SQLite database:
+
+    ```bash
+    # Stop headscale
+    systemctl stop headscale
+
+    # Backup sqlite database
+    cp /var/lib/headscale/db.sqlite /var/lib/headscale/db.sqlite.backup
+
+    # Backup sqlite WAL/SHM files (if they exist)
+    cp /var/lib/headscale/db.sqlite-wal /var/lib/headscale/db.sqlite-wal.backup
+    cp /var/lib/headscale/db.sqlite-shm /var/lib/headscale/db.sqlite-shm.backup
+
+    # Start headscale (migration will run automatically)
+    systemctl start headscale
+    ```
 
 builds:
   - id: headscale
@@ -118,6 +145,8 @@ kos:
       - "{{ .Tag }}"
       - '{{ trimprefix .Tag "v" }}'
       - "sha-{{ .ShortCommit }}"
+    creation_time: "{{.CommitTimestamp}}"
+    ko_data_creation_time: "{{.CommitTimestamp}}"
 
   - id: ghcr-debug
     repositories:

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## Next
 
-## 0.27.0 (2025-xx-xx)
+## 0.27.0 (2025-10-27)
 
 **Minimum supported Tailscale client version: v1.64.0**
 

Dockerfile.derper

@@ -12,7 +12,7 @@ WORKDIR /go/src/tailscale
 ARG TARGETARCH
 RUN GOARCH=$TARGETARCH go install -v ./cmd/derper
 
-FROM alpine:3.18
+FROM alpine:3.22
 RUN apk add --no-cache ca-certificates iptables iproute2 ip6tables curl
 
 COPY --from=build-env /go/bin/* /usr/local/bin/

Dockerfile.integration

@@ -2,13 +2,12 @@
 # and are in no way endorsed by Headscale's maintainers as an
 # official nor supported release or distribution.
 
-FROM docker.io/golang:1.25-bookworm
+FROM docker.io/golang:1.25-trixie
 ARG VERSION=dev
 ENV GOPATH /go
 WORKDIR /go/src/headscale
 
-RUN apt-get update \
-  && apt-get install --no-install-recommends --yes less jq sqlite3 dnsutils \
+RUN apt-get --update install --no-install-recommends --yes less jq sqlite3 dnsutils \
   && rm -rf /var/lib/apt/lists/* \
   && apt-get clean
 RUN mkdir -p /var/run/headscale

Dockerfile.tailscale-HEAD

@@ -36,7 +36,7 @@ RUN GOARCH=$TARGETARCH go install -tags="${BUILD_TAGS}" -ldflags="\
       -X tailscale.com/version.gitCommitStamp=$VERSION_GIT_HASH" \
       -v ./cmd/tailscale ./cmd/tailscaled ./cmd/containerboot
 
-FROM alpine:3.18
+FROM alpine:3.22
 RUN apk add --no-cache ca-certificates iptables iproute2 ip6tables curl
 
 COPY --from=build-env /go/bin/* /usr/local/bin/

cmd/headscale/cli/root.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"runtime"
 	"slices"
+	"strings"
 
 	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/rs/zerolog"
@@ -75,8 +76,9 @@ func initConfig() {
 		if (runtime.GOOS == "linux" || runtime.GOOS == "darwin") &&
 			!versionInfo.Dirty {
 			githubTag := &latest.GithubTag{
-				Owner:      "juanfont",
-				Repository: "headscale",
+				Owner:         "juanfont",
+				Repository:    "headscale",
+				TagFilterFunc: filterPreReleasesIfStable(func() string { return versionInfo.Version }),
 			}
 			res, err := latest.Check(githubTag, versionInfo.Version)
 			if err == nil && res.Outdated {
@@ -91,6 +93,43 @@ func initConfig() {
 	}
 }
 
+var prereleases = []string{"alpha", "beta", "rc", "dev"}
+
+func isPreReleaseVersion(version string) bool {
+	for _, unstable := range prereleases {
+		if strings.Contains(version, unstable) {
+			return true
+		}
+	}
+	return false
+}
+
+// filterPreReleasesIfStable returns a function that filters out
+// pre-release tags if the current version is stable.
+// If the current version is a pre-release, it does not filter anything.
+// versionFunc is a function that returns the current version string, it is
+// a func for testability.
+func filterPreReleasesIfStable(versionFunc func() string) func(string) bool {
+	return func(tag string) bool {
+		version := versionFunc()
+
+		// If we are on a pre-release version, then we do not filter anything
+		// as we want to recommend the user the latest pre-release.
+		if isPreReleaseVersion(version) {
+			return false
+		}
+
+		// If we are on a stable release, filter out pre-releases.
+		for _, ignore := range prereleases {
+			if strings.Contains(tag, ignore) {
+				return true
+			}
+		}
+
+		return false
+	}
+}
+
 var rootCmd = &cobra.Command{
 	Use:   "headscale",
 	Short: "headscale - a Tailscale control server",

cmd/headscale/cli/root_test.go

@@ -0,0 +1,293 @@
+package cli
+
+import (
+	"testing"
+)
+
+func TestFilterPreReleasesIfStable(t *testing.T) {
+	tests := []struct {
+		name           string
+		currentVersion string
+		tag            string
+		expectedFilter bool
+		description    string
+	}{
+		{
+			name:           "stable version filters alpha tag",
+			currentVersion: "0.23.0",
+			tag:            "v0.24.0-alpha.1",
+			expectedFilter: true,
+			description:    "When on stable release, alpha tags should be filtered",
+		},
+		{
+			name:           "stable version filters beta tag",
+			currentVersion: "0.23.0",
+			tag:            "v0.24.0-beta.2",
+			expectedFilter: true,
+			description:    "When on stable release, beta tags should be filtered",
+		},
+		{
+			name:           "stable version filters rc tag",
+			currentVersion: "0.23.0",
+			tag:            "v0.24.0-rc.1",
+			expectedFilter: true,
+			description:    "When on stable release, rc tags should be filtered",
+		},
+		{
+			name:           "stable version allows stable tag",
+			currentVersion: "0.23.0",
+			tag:            "v0.24.0",
+			expectedFilter: false,
+			description:    "When on stable release, stable tags should not be filtered",
+		},
+		{
+			name:           "alpha version allows alpha tag",
+			currentVersion: "0.23.0-alpha.1",
+			tag:            "v0.24.0-alpha.2",
+			expectedFilter: false,
+			description:    "When on alpha release, alpha tags should not be filtered",
+		},
+		{
+			name:           "alpha version allows beta tag",
+			currentVersion: "0.23.0-alpha.1",
+			tag:            "v0.24.0-beta.1",
+			expectedFilter: false,
+			description:    "When on alpha release, beta tags should not be filtered",
+		},
+		{
+			name:           "alpha version allows rc tag",
+			currentVersion: "0.23.0-alpha.1",
+			tag:            "v0.24.0-rc.1",
+			expectedFilter: false,
+			description:    "When on alpha release, rc tags should not be filtered",
+		},
+		{
+			name:           "alpha version allows stable tag",
+			currentVersion: "0.23.0-alpha.1",
+			tag:            "v0.24.0",
+			expectedFilter: false,
+			description:    "When on alpha release, stable tags should not be filtered",
+		},
+		{
+			name:           "beta version allows alpha tag",
+			currentVersion: "0.23.0-beta.1",
+			tag:            "v0.24.0-alpha.1",
+			expectedFilter: false,
+			description:    "When on beta release, alpha tags should not be filtered",
+		},
+		{
+			name:           "beta version allows beta tag",
+			currentVersion: "0.23.0-beta.2",
+			tag:            "v0.24.0-beta.3",
+			expectedFilter: false,
+			description:    "When on beta release, beta tags should not be filtered",
+		},
+		{
+			name:           "beta version allows rc tag",
+			currentVersion: "0.23.0-beta.1",
+			tag:            "v0.24.0-rc.1",
+			expectedFilter: false,
+			description:    "When on beta release, rc tags should not be filtered",
+		},
+		{
+			name:           "beta version allows stable tag",
+			currentVersion: "0.23.0-beta.1",
+			tag:            "v0.24.0",
+			expectedFilter: false,
+			description:    "When on beta release, stable tags should not be filtered",
+		},
+		{
+			name:           "rc version allows alpha tag",
+			currentVersion: "0.23.0-rc.1",
+			tag:            "v0.24.0-alpha.1",
+			expectedFilter: false,
+			description:    "When on rc release, alpha tags should not be filtered",
+		},
+		{
+			name:           "rc version allows beta tag",
+			currentVersion: "0.23.0-rc.1",
+			tag:            "v0.24.0-beta.1",
+			expectedFilter: false,
+			description:    "When on rc release, beta tags should not be filtered",
+		},
+		{
+			name:           "rc version allows rc tag",
+			currentVersion: "0.23.0-rc.2",
+			tag:            "v0.24.0-rc.3",
+			expectedFilter: false,
+			description:    "When on rc release, rc tags should not be filtered",
+		},
+		{
+			name:           "rc version allows stable tag",
+			currentVersion: "0.23.0-rc.1",
+			tag:            "v0.24.0",
+			expectedFilter: false,
+			description:    "When on rc release, stable tags should not be filtered",
+		},
+		{
+			name:           "stable version with patch filters alpha",
+			currentVersion: "0.23.1",
+			tag:            "v0.24.0-alpha.1",
+			expectedFilter: true,
+			description:    "Stable version with patch number should filter alpha tags",
+		},
+		{
+			name:           "stable version with patch allows stable",
+			currentVersion: "0.23.1",
+			tag:            "v0.24.0",
+			expectedFilter: false,
+			description:    "Stable version with patch number should allow stable tags",
+		},
+		{
+			name:           "tag with alpha substring in version number",
+			currentVersion: "0.23.0",
+			tag:            "v1.0.0-alpha.1",
+			expectedFilter: true,
+			description:    "Tags with alpha in version string should be filtered on stable",
+		},
+		{
+			name:           "tag with beta substring in version number",
+			currentVersion: "0.23.0",
+			tag:            "v1.0.0-beta.1",
+			expectedFilter: true,
+			description:    "Tags with beta in version string should be filtered on stable",
+		},
+		{
+			name:           "tag with rc substring in version number",
+			currentVersion: "0.23.0",
+			tag:            "v1.0.0-rc.1",
+			expectedFilter: true,
+			description:    "Tags with rc in version string should be filtered on stable",
+		},
+		{
+			name:           "empty tag on stable version",
+			currentVersion: "0.23.0",
+			tag:            "",
+			expectedFilter: false,
+			description:    "Empty tags should not be filtered",
+		},
+		{
+			name:           "dev version allows all tags",
+			currentVersion: "0.23.0-dev",
+			tag:            "v0.24.0-alpha.1",
+			expectedFilter: false,
+			description:    "Dev versions should not filter any tags (pre-release allows all)",
+		},
+		{
+			name:           "stable version filters dev tag",
+			currentVersion: "0.23.0",
+			tag:            "v0.24.0-dev",
+			expectedFilter: true,
+			description:    "When on stable release, dev tags should be filtered",
+		},
+		{
+			name:           "dev version allows dev tag",
+			currentVersion: "0.23.0-dev",
+			tag:            "v0.24.0-dev.1",
+			expectedFilter: false,
+			description:    "When on dev release, dev tags should not be filtered",
+		},
+		{
+			name:           "dev version allows stable tag",
+			currentVersion: "0.23.0-dev",
+			tag:            "v0.24.0",
+			expectedFilter: false,
+			description:    "When on dev release, stable tags should not be filtered",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := filterPreReleasesIfStable(func() string { return tt.currentVersion })(tt.tag)
+			if result != tt.expectedFilter {
+				t.Errorf("%s: got %v, want %v\nDescription: %s\nCurrent version: %s, Tag: %s",
+					tt.name,
+					result,
+					tt.expectedFilter,
+					tt.description,
+					tt.currentVersion,
+					tt.tag,
+				)
+			}
+		})
+	}
+}
+
+func TestIsPreReleaseVersion(t *testing.T) {
+	tests := []struct {
+		name        string
+		version     string
+		expected    bool
+		description string
+	}{
+		{
+			name:        "stable version",
+			version:     "0.23.0",
+			expected:    false,
+			description: "Stable version should not be pre-release",
+		},
+		{
+			name:        "alpha version",
+			version:     "0.23.0-alpha.1",
+			expected:    true,
+			description: "Alpha version should be pre-release",
+		},
+		{
+			name:        "beta version",
+			version:     "0.23.0-beta.1",
+			expected:    true,
+			description: "Beta version should be pre-release",
+		},
+		{
+			name:        "rc version",
+			version:     "0.23.0-rc.1",
+			expected:    true,
+			description: "RC version should be pre-release",
+		},
+		{
+			name:        "version with alpha substring",
+			version:     "0.23.0-alphabetical",
+			expected:    true,
+			description: "Version containing 'alpha' should be pre-release",
+		},
+		{
+			name:        "version with beta substring",
+			version:     "0.23.0-betamax",
+			expected:    true,
+			description: "Version containing 'beta' should be pre-release",
+		},
+		{
+			name:        "dev version",
+			version:     "0.23.0-dev",
+			expected:    true,
+			description: "Dev version should be pre-release",
+		},
+		{
+			name:        "empty version",
+			version:     "",
+			expected:    false,
+			description: "Empty version should not be pre-release",
+		},
+		{
+			name:        "version with patch number",
+			version:     "0.23.1",
+			expected:    false,
+			description: "Stable version with patch should not be pre-release",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := isPreReleaseVersion(tt.version)
+			if result != tt.expected {
+				t.Errorf("%s: got %v, want %v\nDescription: %s\nVersion: %s",
+					tt.name,
+					result,
+					tt.expected,
+					tt.description,
+					tt.version,
+				)
+			}
+		})
+	}
+}

docs/setup/install/official.md

@@ -7,7 +7,7 @@ Both are available on the [GitHub releases page](https://github.com/juanfont/hea
 
 It is recommended to use our DEB packages to install headscale on a Debian based system as those packages configure a
 local user to run headscale, provide a default configuration and ship with a systemd service file. Supported
-distributions are Ubuntu 22.04 or newer, Debian 11 or newer.
+distributions are Ubuntu 22.04 or newer, Debian 12 or newer.
 
 1.  Download the [latest headscale package](https://github.com/juanfont/headscale/releases/latest) for your platform (`.deb` for Ubuntu and Debian).
 

hscontrol/app.go

@@ -446,6 +446,7 @@ func (h *Headscale) createRouter(grpcMux *grpcRuntime.ServeMux) *mux.Router {
 
 	router.HandleFunc("/robots.txt", h.RobotsHandler).Methods(http.MethodGet)
 	router.HandleFunc("/health", h.HealthHandler).Methods(http.MethodGet)
+	router.HandleFunc("/version", h.VersionHandler).Methods(http.MethodGet)
 	router.HandleFunc("/key", h.KeyHandler).Methods(http.MethodGet)
 	router.HandleFunc("/register/{registration_id}", h.authProvider.RegisterHandler).
 		Methods(http.MethodGet)

hscontrol/derp/derp.go

@@ -12,6 +12,7 @@ import (
 	"net/url"
 	"os"
 	"reflect"
+	"slices"
 	"sync"
 	"time"
 
@@ -126,7 +127,17 @@ func shuffleDERPMap(dm *tailcfg.DERPMap) {
 		return
 	}
 
-	for id, region := range dm.Regions {
+	// Collect region IDs and sort them to ensure deterministic iteration order.
+	// Map iteration order is non-deterministic in Go, which would cause the
+	// shuffle to be non-deterministic even with a fixed seed.
+	ids := make([]int, 0, len(dm.Regions))
+	for id := range dm.Regions {
+		ids = append(ids, id)
+	}
+	slices.Sort(ids)
+
+	for _, id := range ids {
+		region := dm.Regions[id]
 		if len(region.Nodes) == 0 {
 			continue
 		}

hscontrol/derp/derp_test.go

@@ -83,9 +83,9 @@ func TestShuffleDERPMapDeterministic(t *testing.T) {
 						RegionCode: "sea",
 						RegionName: "Seattle",
 						Nodes: []*tailcfg.DERPNode{
-							{Name: "10b", RegionID: 10, HostName: "derp10b.tailscale.com"},
-							{Name: "10c", RegionID: 10, HostName: "derp10c.tailscale.com"},
 							{Name: "10d", RegionID: 10, HostName: "derp10d.tailscale.com"},
+							{Name: "10c", RegionID: 10, HostName: "derp10c.tailscale.com"},
+							{Name: "10b", RegionID: 10, HostName: "derp10b.tailscale.com"},
 						},
 					},
 					2: {
@@ -93,9 +93,9 @@ func TestShuffleDERPMapDeterministic(t *testing.T) {
 						RegionCode: "sfo",
 						RegionName: "San Francisco",
 						Nodes: []*tailcfg.DERPNode{
-							{Name: "2f", RegionID: 2, HostName: "derp2f.tailscale.com"},
-							{Name: "2e", RegionID: 2, HostName: "derp2e.tailscale.com"},
 							{Name: "2d", RegionID: 2, HostName: "derp2d.tailscale.com"},
+							{Name: "2e", RegionID: 2, HostName: "derp2e.tailscale.com"},
+							{Name: "2f", RegionID: 2, HostName: "derp2f.tailscale.com"},
 						},
 					},
 				},
@@ -169,6 +169,74 @@ func TestShuffleDERPMapDeterministic(t *testing.T) {
 				},
 			},
 		},
+		{
+			name:       "same dataset with another base domain",
+			baseDomain: "another.example.com",
+			derpMap: &tailcfg.DERPMap{
+				Regions: map[int]*tailcfg.DERPRegion{
+					4: {
+						RegionID:   4,
+						RegionCode: "fra",
+						RegionName: "Frankfurt",
+						Nodes: []*tailcfg.DERPNode{
+							{Name: "4f", RegionID: 4, HostName: "derp4f.tailscale.com"},
+							{Name: "4g", RegionID: 4, HostName: "derp4g.tailscale.com"},
+							{Name: "4h", RegionID: 4, HostName: "derp4h.tailscale.com"},
+							{Name: "4i", RegionID: 4, HostName: "derp4i.tailscale.com"},
+						},
+					},
+				},
+			},
+			expected: &tailcfg.DERPMap{
+				Regions: map[int]*tailcfg.DERPRegion{
+					4: {
+						RegionID:   4,
+						RegionCode: "fra",
+						RegionName: "Frankfurt",
+						Nodes: []*tailcfg.DERPNode{
+							{Name: "4h", RegionID: 4, HostName: "derp4h.tailscale.com"},
+							{Name: "4f", RegionID: 4, HostName: "derp4f.tailscale.com"},
+							{Name: "4g", RegionID: 4, HostName: "derp4g.tailscale.com"},
+							{Name: "4i", RegionID: 4, HostName: "derp4i.tailscale.com"},
+						},
+					},
+				},
+			},
+		},
+		{
+			name:       "same dataset with yet another base domain",
+			baseDomain: "yetanother.example.com",
+			derpMap: &tailcfg.DERPMap{
+				Regions: map[int]*tailcfg.DERPRegion{
+					4: {
+						RegionID:   4,
+						RegionCode: "fra",
+						RegionName: "Frankfurt",
+						Nodes: []*tailcfg.DERPNode{
+							{Name: "4f", RegionID: 4, HostName: "derp4f.tailscale.com"},
+							{Name: "4g", RegionID: 4, HostName: "derp4g.tailscale.com"},
+							{Name: "4h", RegionID: 4, HostName: "derp4h.tailscale.com"},
+							{Name: "4i", RegionID: 4, HostName: "derp4i.tailscale.com"},
+						},
+					},
+				},
+			},
+			expected: &tailcfg.DERPMap{
+				Regions: map[int]*tailcfg.DERPRegion{
+					4: {
+						RegionID:   4,
+						RegionCode: "fra",
+						RegionName: "Frankfurt",
+						Nodes: []*tailcfg.DERPNode{
+							{Name: "4i", RegionID: 4, HostName: "derp4i.tailscale.com"},
+							{Name: "4h", RegionID: 4, HostName: "derp4h.tailscale.com"},
+							{Name: "4f", RegionID: 4, HostName: "derp4f.tailscale.com"},
+							{Name: "4g", RegionID: 4, HostName: "derp4g.tailscale.com"},
+						},
+					},
+				},
+			},
+		},
 	}
 
 	for _, tt := range tests {

hscontrol/handlers.go

@@ -201,6 +201,24 @@ func (h *Headscale) RobotsHandler(
 	}
 }
 
+// VersionHandler returns version information about the Headscale server
+// Listens in /version.
+func (h *Headscale) VersionHandler(
+	writer http.ResponseWriter,
+	req *http.Request,
+) {
+	writer.Header().Set("Content-Type", "application/json")
+	writer.WriteHeader(http.StatusOK)
+
+	versionInfo := types.GetVersionInfo()
+	if err := json.NewEncoder(writer).Encode(versionInfo); err != nil {
+		log.Error().
+			Caller().
+			Err(err).
+			Msg("Failed to write version response")
+	}
+}
+
 var codeStyleRegisterWebAPI = styles.Props{
 	styles.Display:         "block",
 	styles.Padding:         "20px",

integration/hsic/hsic.go

@@ -1232,26 +1232,26 @@ func (h *HeadscaleInContainer) writePolicy(pol *policyv2.Policy) error {
 }
 
 func (h *HeadscaleInContainer) PID() (int, error) {
-	cmd := []string{"bash", "-c", `ps aux | grep headscale | grep -v grep | awk '{print $2}'`}
-	output, err := h.Execute(cmd)
+	// Use pidof to find the headscale process, which is more reliable than grep
+	// as it only looks for the actual binary name, not processes that contain
+	// "headscale" in their command line (like the dlv debugger).
+	output, err := h.Execute([]string{"pidof", "headscale"})
 	if err != nil {
-		return 0, fmt.Errorf("failed to execute command: %w", err)
+		// pidof returns exit code 1 when no process is found
+		return 0, os.ErrNotExist
 	}
 
-	lines := strings.TrimSpace(output)
-	if lines == "" {
-		return 0, os.ErrNotExist // No output means no process found
+	// pidof returns space-separated PIDs on a single line
+	pidStrs := strings.Fields(strings.TrimSpace(output))
+	if len(pidStrs) == 0 {
+		return 0, os.ErrNotExist
 	}
 
-	pids := make([]int, 0, len(lines))
-	for _, line := range strings.Split(lines, "\n") {
-		line = strings.TrimSpace(line)
-		if line == "" {
-			continue
-		}
-		pidInt, err := strconv.Atoi(line)
+	pids := make([]int, 0, len(pidStrs))
+	for _, pidStr := range pidStrs {
+		pidInt, err := strconv.Atoi(pidStr)
 		if err != nil {
-			return 0, fmt.Errorf("parsing PID: %w", err)
+			return 0, fmt.Errorf("parsing PID %q: %w", pidStr, err)
 		}
 		// We dont care about the root pid for the container
 		if pidInt == 1 {
@@ -1266,7 +1266,9 @@ func (h *HeadscaleInContainer) PID() (int, error) {
 	case 1:
 		return pids[0], nil
 	default:
-		return 0, errors.New("multiple headscale processes running")
+		// If we still have multiple PIDs, return the first one as a fallback
+		// This can happen in edge cases during startup/shutdown
+		return pids[0], nil
 	}
 }
 

integration/route_test.go

@@ -24,6 +24,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	xmaps "golang.org/x/exp/maps"
+	"tailscale.com/envknob"
 	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/net/tsaddr"
 	"tailscale.com/tailcfg"
@@ -2215,11 +2216,31 @@ func TestAutoApproveMultiNetwork(t *testing.T) {
 		},
 	}
 
+	// Check if we should run the full matrix of tests
+	// By default, we only run a minimal subset to avoid overwhelming Docker/disk
+	// Set HEADSCALE_INTEGRATION_FULL_MATRIX=1 to run all combinations
+	fullMatrix := envknob.Bool("HEADSCALE_INTEGRATION_FULL_MATRIX")
+
+	// Minimal test set: 3 tests covering all key dimensions
+	// - Both auth methods (authkey, webauth)
+	// - All 3 approver types (tag, user, group)
+	// - Both policy modes (database, file)
+	// - Both advertiseDuringUp values (true, false)
+	minimalTestSet := map[string]bool{
+		"authkey-tag-advertiseduringup-false-pol-database":  true, // authkey + database + tag + false
+		"webauth-user-advertiseduringup-true-pol-file":      true, // webauth + file + user + true
+		"authkey-group-advertiseduringup-false-pol-file":    true, // authkey + file + group + false
+	}
+
 	for _, tt := range tests {
 		for _, polMode := range []types.PolicyMode{types.PolicyModeDB, types.PolicyModeFile} {
 			for _, advertiseDuringUp := range []bool{false, true} {
 				name := fmt.Sprintf("%s-advertiseduringup-%t-pol-%s", tt.name, advertiseDuringUp, polMode)
 				t.Run(name, func(t *testing.T) {
+					// Skip tests not in minimal set unless full matrix is enabled
+					if !fullMatrix && !minimalTestSet[name] {
+						t.Skip("Skipping to reduce test matrix size. Set HEADSCALE_INTEGRATION_FULL_MATRIX=1 to run all tests.")
+					}
 					scenario, err := NewScenario(tt.spec)
 					require.NoErrorf(t, err, "failed to create scenario: %s", err)
 					defer scenario.ShutdownAssertNoPanics(t)