modernize: run gopls modernize to bring up to 1.25 (#2920)

cmd/headscale/cli/utils.go

@@ -130,7 +130,7 @@ func newHeadscaleCLIWithConfig() (context.Context, v1.HeadscaleServiceClient, *g
 	return ctx, client, conn, cancel
 }
 
-func output(result interface{}, override string, outputFormat string) string {
+func output(result any, override string, outputFormat string) string {
 	var jsonBytes []byte
 	var err error
 	switch outputFormat {
@@ -158,7 +158,7 @@ func output(result interface{}, override string, outputFormat string) string {
 }
 
 // SuccessOutput prints the result to stdout and exits with status code 0.
-func SuccessOutput(result interface{}, override string, outputFormat string) {
+func SuccessOutput(result any, override string, outputFormat string) {
 	fmt.Println(output(result, override, outputFormat))
 	os.Exit(0)
 }

cmd/hi/docker.go

@@ -456,8 +456,8 @@ func boolToInt(b bool) int {
 // DockerContext represents Docker context information.
 type DockerContext struct {
 	Name      string         `json:"Name"`
-	Metadata  map[string]interface{} `json:"Metadata"`
+	Metadata  map[string]any `json:"Metadata"`
-	Endpoints map[string]interface{} `json:"Endpoints"`
+	Endpoints map[string]any `json:"Endpoints"`
 	Current   bool           `json:"Current"`
 }
 
@@ -473,7 +473,7 @@ func createDockerClient() (*client.Client, error) {
 
 	if contextInfo != nil {
 		if endpoints, ok := contextInfo.Endpoints["docker"]; ok {
-			if endpointMap, ok := endpoints.(map[string]interface{}); ok {
+			if endpointMap, ok := endpoints.(map[string]any); ok {
 				if host, ok := endpointMap["Host"].(string); ok {
 					if runConfig.Verbose {
 						log.Printf("Using Docker host from context '%s': %s", contextInfo.Name, host)

hscontrol/auth_test.go

@@ -2760,7 +2760,7 @@ func TestPreAuthKeyLogoutAndReloginDifferentUser(t *testing.T) {
 	require.Equal(t, 2, user2NodesAfter.Len(), "user2 should still have 2 nodes (old nodes from original registration)")
 
 	// Verify original nodes still exist with original users
-	for i := 0; i < 2; i++ {
+	for i := range 2 {
 		node := nodes[i]
 		// User1's original nodes should still be owned by user1
 		registeredNode, found := app.state.GetNodeByMachineKey(node.machineKey.Public(), types.UserID(user1.ID))
@@ -3195,6 +3195,7 @@ func TestNodeReregistrationWithExpiredPreAuthKey(t *testing.T) {
 	assert.Error(t, err, "expired pre-auth key should be rejected")
 	assert.Contains(t, err.Error(), "authkey expired", "error should mention key expiration")
 }
+
 // TestGitHubIssue2830_ExistingNodeCanReregisterWithUsedPreAuthKey tests that an existing node
 // can re-register using a pre-auth key that's already marked as Used=true, as long as:
 // 1. The node is re-registering with the same MachineKey it originally used
@@ -3204,6 +3205,7 @@ func TestNodeReregistrationWithExpiredPreAuthKey(t *testing.T) {
 //
 // Background: When Docker/Kubernetes containers restart, they keep their persistent state
 // (including the MachineKey), but container entrypoints unconditionally run:
+//
 //	tailscale up --authkey=$TS_AUTHKEY
 //
 // This caused nodes to be rejected after restart because the pre-auth key was already

hscontrol/db/text_serialiser.go

@@ -31,7 +31,7 @@ func decodingError(name string, err error) error {
 // have a type that implements encoding.TextUnmarshaler.
 type TextSerialiser struct{}
 
-func (TextSerialiser) Scan(ctx context.Context, field *schema.Field, dst reflect.Value, dbValue interface{}) (err error) {
+func (TextSerialiser) Scan(ctx context.Context, field *schema.Field, dst reflect.Value, dbValue any) error {
 	fieldValue := reflect.New(field.FieldType)
 
 	// If the field is a pointer, we need to dereference it to get the actual type
@@ -77,10 +77,10 @@ func (TextSerialiser) Scan(ctx context.Context, field *schema.Field, dst reflect
 		}
 	}
 
-	return err
+	return nil
 }
 
-func (TextSerialiser) Value(ctx context.Context, field *schema.Field, dst reflect.Value, fieldValue interface{}) (interface{}, error) {
+func (TextSerialiser) Value(ctx context.Context, field *schema.Field, dst reflect.Value, fieldValue any) (any, error) {
 	switch v := fieldValue.(type) {
 	case encoding.TextMarshaler:
 		// If the value is nil, we return nil, however, go nil values are not

hscontrol/mapper/batcher_test.go

@@ -1136,13 +1136,9 @@ func XTestBatcherChannelClosingRace(t *testing.T) {
 				// First connection
 				ch1 := make(chan *tailcfg.MapResponse, 1)
 
-				wg.Add(1)
+				wg.Go(func() {
-
-				go func() {
-					defer wg.Done()
-
 					batcher.AddNode(testNode.n.ID, ch1, tailcfg.CapabilityVersion(100))
-				}()
+				})
 
 				// Add real work during connection chaos
 				if i%10 == 0 {
@@ -1152,24 +1148,17 @@ func XTestBatcherChannelClosingRace(t *testing.T) {
 				// Rapid second connection - should replace ch1
 				ch2 := make(chan *tailcfg.MapResponse, 1)
 
-				wg.Add(1)
+				wg.Go(func() {
-
-				go func() {
-					defer wg.Done()
-
 					time.Sleep(1 * time.Microsecond)
 					batcher.AddNode(testNode.n.ID, ch2, tailcfg.CapabilityVersion(100))
-				}()
+				})
 
 				// Remove second connection
-				wg.Add(1)
-
-				go func() {
-					defer wg.Done()
 
+				wg.Go(func() {
 					time.Sleep(2 * time.Microsecond)
 					batcher.RemoveNode(testNode.n.ID, ch2)
-				}()
+				})
 
 				wg.Wait()
 
@@ -1789,10 +1778,7 @@ func XTestBatcherScalability(t *testing.T) {
 							// This ensures some nodes stay connected to continue receiving updates
 							startIdx := cycle % len(testNodes)
 
-							endIdx := startIdx + len(testNodes)/4
+							endIdx := min(startIdx+len(testNodes)/4, len(testNodes))
-							if endIdx > len(testNodes) {
-								endIdx = len(testNodes)
-							}
 
 							if startIdx >= endIdx {
 								startIdx = 0
@@ -2313,7 +2299,7 @@ func TestBatcherRapidReconnection(t *testing.T) {
 			receivedCount := 0
 			timeout := time.After(500 * time.Millisecond)
 
-			for i := 0; i < len(allNodes); i++ {
+			for i := range allNodes {
 				select {
 				case update := <-newChannels[i]:
 					if update != nil {

hscontrol/policy/v2/filter.go

@@ -3,6 +3,7 @@ package v2
 import (
 	"errors"
 	"fmt"
+	"slices"
 	"time"
 
 	"github.com/juanfont/headscale/hscontrol/types"
@@ -178,11 +179,8 @@ func (pol *Policy) compileACLWithAutogroupSelf(
 			for _, ips := range resolvedSrcIPs {
 				for _, n := range sameUserNodes {
 					// Check if any of this node's IPs are in the source set
-					for _, nodeIP := range n.IPs() {
+					if slices.ContainsFunc(n.IPs(), ips.Contains) {
-						if ips.Contains(nodeIP) {
 						n.AppendToIPSet(&srcIPs)
-							break
-						}
 					}
 				}
 			}
@@ -375,11 +373,8 @@ func (pol *Policy) compileSSHPolicy(
 				var filteredSrcIPs netipx.IPSetBuilder
 				for _, n := range sameUserNodes {
 					// Check if any of this node's IPs are in the source set
-					for _, nodeIP := range n.IPs() {
+					if slices.ContainsFunc(n.IPs(), srcIPs.Contains) {
-						if srcIPs.Contains(nodeIP) {
+						n.AppendToIPSet(&filteredSrcIPs) // Found this node, move to next
-							n.AppendToIPSet(&filteredSrcIPs)
-							break // Found this node, move to next
-						}
 					}
 				}
 

hscontrol/policy/v2/filter_test.go

@@ -3,6 +3,7 @@ package v2
 import (
 	"encoding/json"
 	"net/netip"
+	"slices"
 	"strings"
 	"testing"
 	"time"
@@ -906,14 +907,7 @@ func TestCompileFilterRulesForNodeWithAutogroupSelf(t *testing.T) {
 	}
 
 	for _, expectedIP := range expectedDestIPs {
-		found := false
+		found := slices.Contains(actualDestIPs, expectedIP)
-
-		for _, actualIP := range actualDestIPs {
-			if actualIP == expectedIP {
-				found = true
-				break
-			}
-		}
 
 		if !found {
 			t.Errorf("expected destination IP %s to be included, got: %v", expectedIP, actualDestIPs)

hscontrol/policy/v2/types.go

@@ -1007,7 +1007,7 @@ func (g Groups) Contains(group *Group) error {
 // with "group:". If any group name is invalid, an error is returned.
 func (g *Groups) UnmarshalJSON(b []byte) error {
 	// First unmarshal as a generic map to validate group names first
-	var rawMap map[string]interface{}
+	var rawMap map[string]any
 	if err := json.Unmarshal(b, &rawMap); err != nil {
 		return err
 	}
@@ -1024,7 +1024,7 @@ func (g *Groups) UnmarshalJSON(b []byte) error {
 	rawGroups := make(map[string][]string)
 	for key, value := range rawMap {
 		switch v := value.(type) {
-		case []interface{}:
+		case []any:
 			// Convert []interface{} to []string
 			var stringSlice []string
 			for _, item := range v {

hscontrol/policy/v2/utils.go

@@ -39,9 +39,10 @@ func parsePortRange(portDef string) ([]tailcfg.PortRange, error) {
 	}
 
 	var portRanges []tailcfg.PortRange
-	parts := strings.Split(portDef, ",")
 
-	for _, part := range parts {
+	parts := strings.SplitSeq(portDef, ",")
+
+	for part := range parts {
 		if strings.Contains(part, "-") {
 			rangeParts := strings.Split(part, "-")
 			rangeParts = slices.DeleteFunc(rangeParts, func(e string) bool {

hscontrol/state/debug.go

@@ -200,9 +200,9 @@ func (s *State) DebugSSHPolicies() map[string]*tailcfg.SSHPolicy {
 }
 
 // DebugRegistrationCache returns debug information about the registration cache.
-func (s *State) DebugRegistrationCache() map[string]interface{} {
+func (s *State) DebugRegistrationCache() map[string]any {
 	// The cache doesn't expose internal statistics, so we provide basic info
-	result := map[string]interface{}{
+	result := map[string]any{
 		"type":       "zcache",
 		"expiration": registerCacheExpiration.String(),
 		"cleanup":    registerCacheCleanup.String(),

hscontrol/state/node_store_test.go

@@ -872,7 +872,7 @@ func TestNodeStoreConcurrentPutNode(t *testing.T) {
 
 	var wg sync.WaitGroup
 	results := make(chan bool, concurrentOps)
-	for i := 0; i < concurrentOps; i++ {
+	for i := range concurrentOps {
 		wg.Add(1)
 		go func(nodeID int) {
 			defer wg.Done()
@@ -904,7 +904,7 @@ func TestNodeStoreBatchingEfficiency(t *testing.T) {
 
 	var wg sync.WaitGroup
 	results := make(chan bool, ops)
-	for i := 0; i < ops; i++ {
+	for i := range ops {
 		wg.Add(1)
 		go func(nodeID int) {
 			defer wg.Done()
@@ -941,11 +941,12 @@ func TestNodeStoreRaceConditions(t *testing.T) {
 	var wg sync.WaitGroup
 	errors := make(chan error, numGoroutines*opsPerGoroutine)
 
-	for i := 0; i < numGoroutines; i++ {
+	for i := range numGoroutines {
 		wg.Add(1)
 		go func(gid int) {
 			defer wg.Done()
-			for j := 0; j < opsPerGoroutine; j++ {
+
+			for j := range opsPerGoroutine {
 				switch j % 3 {
 				case 0:
 					resultNode, _ := store.UpdateNode(nodeID, func(n *types.Node) {
@@ -993,7 +994,7 @@ func TestNodeStoreResourceCleanup(t *testing.T) {
 	afterStartGoroutines := runtime.NumGoroutine()
 
 	const ops = 100
-	for i := 0; i < ops; i++ {
+	for i := range ops {
 		nodeID := types.NodeID(i + 1)
 		node := createConcurrentTestNode(nodeID, "cleanup-node")
 		resultNode := store.PutNode(node)
@@ -1100,7 +1101,7 @@ func TestNodeStoreOperationTimeout(t *testing.T) {
 
 // --- Edge case: update non-existent node ---
 func TestNodeStoreUpdateNonExistentNode(t *testing.T) {
-	for i := 0; i < 10; i++ {
+	for i := range 10 {
 		store := NewNodeStore(nil, allowAllPeersFunc, TestBatchSize, TestBatchTimeout)
 		store.Start()
 		nonExistentID := types.NodeID(999 + i)
@@ -1124,8 +1125,7 @@ func BenchmarkNodeStoreAllocations(b *testing.B) {
 	store.Start()
 	defer store.Stop()
 
-	b.ResetTimer()
+	for i := 0; b.Loop(); i++ {
-	for i := 0; i < b.N; i++ {
 		nodeID := types.NodeID(i + 1)
 		node := createConcurrentTestNode(nodeID, "bench-node")
 		store.PutNode(node)

hscontrol/types/common.go

@@ -220,10 +220,12 @@ func DefaultBatcherWorkers() int {
 // DefaultBatcherWorkersFor returns the default number of batcher workers for a given CPU count.
 // Default to 3/4 of CPU cores, minimum 1, no maximum.
 func DefaultBatcherWorkersFor(cpuCount int) int {
-	defaultWorkers := (cpuCount * 3) / 4
+	const (
-	if defaultWorkers < 1 {
+		workerNumerator   = 3
-		defaultWorkers = 1
+		workerDenominator = 4
-	}
+	)
+
+	defaultWorkers := max((cpuCount*workerNumerator)/workerDenominator, 1)
 
 	return defaultWorkers
 }

hscontrol/util/log.go

@@ -49,22 +49,22 @@ func (l *DBLogWrapper) LogMode(gormLogger.LogLevel) gormLogger.Interface {
 	return l
 }
 
-func (l *DBLogWrapper) Info(ctx context.Context, msg string, data ...interface{}) {
+func (l *DBLogWrapper) Info(ctx context.Context, msg string, data ...any) {
 	l.Logger.Info().Msgf(msg, data...)
 }
 
-func (l *DBLogWrapper) Warn(ctx context.Context, msg string, data ...interface{}) {
+func (l *DBLogWrapper) Warn(ctx context.Context, msg string, data ...any) {
 	l.Logger.Warn().Msgf(msg, data...)
 }
 
-func (l *DBLogWrapper) Error(ctx context.Context, msg string, data ...interface{}) {
+func (l *DBLogWrapper) Error(ctx context.Context, msg string, data ...any) {
 	l.Logger.Error().Msgf(msg, data...)
 }
 
 func (l *DBLogWrapper) Trace(ctx context.Context, begin time.Time, fc func() (sql string, rowsAffected int64), err error) {
 	elapsed := time.Since(begin)
 	sql, rowsAffected := fc()
-	fields := map[string]interface{}{
+	fields := map[string]any{
 		"duration":     elapsed,
 		"sql":          sql,
 		"rowsAffected": rowsAffected,
@@ -83,7 +83,7 @@ func (l *DBLogWrapper) Trace(ctx context.Context, begin time.Time, fc func() (sq
 	l.Logger.Debug().Fields(fields).Msgf("")
 }
 
-func (l *DBLogWrapper) ParamsFilter(ctx context.Context, sql string, params ...interface{}) (string, []interface{}) {
+func (l *DBLogWrapper) ParamsFilter(ctx context.Context, sql string, params ...any) (string, []any) {
 	if l.ParameterizedQueries {
 		return sql, nil
 	}

integration/api_auth_test.go

@@ -98,7 +98,7 @@ func TestAPIAuthenticationBypass(t *testing.T) {
 
 		// Should NOT contain user data after "Unauthorized"
 		// This is the security bypass - if users array is present, auth was bypassed
-		var jsonCheck map[string]interface{}
+		var jsonCheck map[string]any
 		jsonErr := json.Unmarshal(body, &jsonCheck)
 
 		// If we can unmarshal JSON and it contains "users", that's the bypass
@@ -278,8 +278,8 @@ func TestAPIAuthenticationBypassCurl(t *testing.T) {
 		var responseBody string
 
 		for _, line := range lines {
-			if strings.HasPrefix(line, "HTTP_CODE:") {
+			if after, ok := strings.CutPrefix(line, "HTTP_CODE:"); ok {
-				httpCode = strings.TrimPrefix(line, "HTTP_CODE:")
+				httpCode = after
 			} else {
 				responseBody += line
 			}
@@ -324,8 +324,8 @@ func TestAPIAuthenticationBypassCurl(t *testing.T) {
 		var responseBody string
 
 		for _, line := range lines {
-			if strings.HasPrefix(line, "HTTP_CODE:") {
+			if after, ok := strings.CutPrefix(line, "HTTP_CODE:"); ok {
-				httpCode = strings.TrimPrefix(line, "HTTP_CODE:")
+				httpCode = after
 			} else {
 				responseBody += line
 			}
@@ -359,8 +359,8 @@ func TestAPIAuthenticationBypassCurl(t *testing.T) {
 		var responseBody string
 
 		for _, line := range lines {
-			if strings.HasPrefix(line, "HTTP_CODE:") {
+			if after, ok := strings.CutPrefix(line, "HTTP_CODE:"); ok {
-				httpCode = strings.TrimPrefix(line, "HTTP_CODE:")
+				httpCode = after
 			} else {
 				responseBody += line
 			}

integration/helpers.go

@@ -56,13 +56,6 @@ type NodeSystemStatus struct {
 	NodeStore        bool
 }
 
-// requireNotNil validates that an object is not nil and fails the test if it is.
-// This helper provides consistent error messaging for nil checks in integration tests.
-func requireNotNil(t *testing.T, object interface{}) {
-	t.Helper()
-	require.NotNil(t, object)
-}
-
 // requireNoErrHeadscaleEnv validates that headscale environment creation succeeded.
 // Provides specific error context for headscale environment setup failures.
 func requireNoErrHeadscaleEnv(t *testing.T, err error) {

integration/hsic/hsic.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"maps"
 	"net/http"
 	"net/netip"
 	"os"
@@ -132,9 +133,7 @@ func WithCustomTLS(cert, key []byte) Option {
 // can be used to override Headscale configuration.
 func WithConfigEnv(configEnv map[string]string) Option {
 	return func(hsic *HeadscaleInContainer) {
-		for key, value := range configEnv {
+		maps.Copy(hsic.env, configEnv)
-			hsic.env[key] = value
-		}
 	}
 }
 

integration/scenario.go

@@ -14,6 +14,7 @@ import (
 	"net/netip"
 	"net/url"
 	"os"
+	"slices"
 	"strconv"
 	"strings"
 	"sync"
@@ -1159,12 +1160,10 @@ func (s *Scenario) FindTailscaleClientByIP(ip netip.Addr) (TailscaleClient, erro
 
 	for _, client := range clients {
 		ips, _ := client.IPs()
-		for _, ip2 := range ips {
+		if slices.Contains(ips, ip) {
-			if ip == ip2 {
 			return client, nil
 		}
 	}
-	}
 
 	return nil, errNoClientFound
 }

tools/capver/main.go

@@ -11,6 +11,7 @@ import (
 	"net/http"
 	"os"
 	"regexp"
+	"slices"
 	"sort"
 	"strconv"
 	"strings"
@@ -116,10 +117,7 @@ func calculateMinSupportedCapabilityVersion(versions map[string]tailcfg.Capabili
 	sort.Strings(majorMinors)
 
 	// Take the latest 10 versions
-	supportedCount := supportedMajorMinorVersions
+	supportedCount := min(len(majorMinors), supportedMajorMinorVersions)
-	if len(majorMinors) < supportedCount {
-		supportedCount = len(majorMinors)
-	}
 
 	if supportedCount == 0 {
 		return fallbackCapVer
@@ -168,9 +166,7 @@ func writeCapabilityVersionsToFile(versions map[string]tailcfg.CapabilityVersion
 	}
 
 	capsSorted := xmaps.Keys(capVarToTailscaleVer)
-	sort.Slice(capsSorted, func(i, j int) bool {
+	slices.Sort(capsSorted)
-		return capsSorted[i] < capsSorted[j]
-	})
 
 	for _, capVer := range capsSorted {
 		fmt.Fprintf(&content, "\t%d:\t\t\"%s\",\n", capVer, capVarToTailscaleVer[capVer])
@@ -223,10 +219,7 @@ func writeTestDataFile(versions map[string]tailcfg.CapabilityVersion, minSupport
 	sort.Strings(majorMinors)
 
 	// Take latest 10
-	supportedCount := supportedMajorMinorVersions
+	supportedCount := min(len(majorMinors), supportedMajorMinorVersions)
-	if len(majorMinors) < supportedCount {
-		supportedCount = len(majorMinors)
-	}
 
 	latest10 := majorMinors[len(majorMinors)-supportedCount:]
 	latest3 := majorMinors[len(majorMinors)-3:]
@@ -308,9 +301,7 @@ func writeTestDataFile(versions map[string]tailcfg.CapabilityVersion, minSupport
 
 	// Add a few more test cases
 	capsSorted := xmaps.Keys(capVerToTailscaleVer)
-	sort.Slice(capsSorted, func(i, j int) bool {
+	slices.Sort(capsSorted)
-		return capsSorted[i] < capsSorted[j]
-	})
 
 	testCount := 0
 	for _, capVer := range capsSorted {