all: use any instead of interface{}

My favorite part of generics.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>

cmd/cloner/cloner.go

@@ -69,14 +69,14 @@ func main() {
 		gen(buf, imports, typ, pkg.Types)
 	}
 
-	w := func(format string, args ...interface{}) {
+	w := func(format string, args ...any) {
 		fmt.Fprintf(buf, format+"\n", args...)
 	}
 	if *flagCloneFunc {
 		w("// Clone duplicates src into dst and reports whether it succeeded.")
 		w("// To succeed, <src, dst> must be of types <*T, *T> or <*T, **T>,")
 		w("// where T is one of %s.", *flagTypes)
-		w("func Clone(dst, src interface{}) bool {")
+		w("func Clone(dst, src any) bool {")
 		w("	switch src := src.(type) {")
 		for _, typeName := range typeNames {
 			w("	case *%s:", typeName)
@@ -158,7 +158,7 @@ func gen(buf *bytes.Buffer, imports map[string]struct{}, typ *types.Named, thisP
 	fmt.Fprintf(buf, "// Clone makes a deep copy of %s.\n", name)
 	fmt.Fprintf(buf, "// The result aliases no memory with the original.\n")
 	fmt.Fprintf(buf, "func (src *%s) Clone() *%s {\n", name, name)
-	writef := func(format string, args ...interface{}) {
+	writef := func(format string, args ...any) {
 		fmt.Fprintf(buf, "\t"+format+"\n", args...)
 	}
 	writef("if src == nil {")

cmd/derpprobe/derpprobe.go

@@ -78,11 +78,11 @@ type overallStatus struct {
 	good, bad []string
 }
 
-func (st *overallStatus) addBadf(format string, a ...interface{}) {
+func (st *overallStatus) addBadf(format string, a ...any) {
 	st.bad = append(st.bad, fmt.Sprintf(format, a...))
 }
 
-func (st *overallStatus) addGoodf(format string, a ...interface{}) {
+func (st *overallStatus) addGoodf(format string, a ...any) {
 	st.good = append(st.good, fmt.Sprintf(format, a...))
 }
 
@@ -426,7 +426,7 @@ func probeNodePair(ctx context.Context, dm *tailcfg.DERPMap, from, to *tailcfg.D
 	}
 
 	// Receive the random packet.
-	recvc := make(chan interface{}, 1) // either derp.ReceivedPacket or error
+	recvc := make(chan any, 1) // either derp.ReceivedPacket or error
 	go func() {
 		for {
 			m, err := toc.Recv()

cmd/tailscale/cli/cert.go

@@ -79,7 +79,7 @@ func runCert(ctx context.Context, args []string) error {
 	}
 	domain := args[0]
 
-	printf := func(format string, a ...interface{}) {
+	printf := func(format string, a ...any) {
 		printf(format, a...)
 	}
 	if certArgs.certFile == "-" || certArgs.keyFile == "-" {

cmd/tailscale/cli/cli.go

@@ -35,7 +35,7 @@ import (
 var Stderr io.Writer = os.Stderr
 var Stdout io.Writer = os.Stdout
 
-func printf(format string, a ...interface{}) {
+func printf(format string, a ...any) {
 	fmt.Fprintf(Stdout, format, a...)
 }
 
@@ -44,7 +44,7 @@ func printf(format string, a ...interface{}) {
 //
 // It's not named println because that looks like the Go built-in
 // which goes to stderr and formats slightly differently.
-func outln(a ...interface{}) {
+func outln(a ...any) {
 	fmt.Fprintln(Stdout, a...)
 }
 
@@ -216,7 +216,7 @@ change in the future.
 	return err
 }
 
-func fatalf(format string, a ...interface{}) {
+func fatalf(format string, a ...any) {
 	if Fatalf != nil {
 		Fatalf(format, a...)
 		return
@@ -226,7 +226,7 @@ func fatalf(format string, a ...interface{}) {
 }
 
 // Fatalf, if non-nil, is used instead of log.Fatalf.
-var Fatalf func(format string, a ...interface{})
+var Fatalf func(format string, a ...any)
 
 var rootArgs struct {
 	socket string

cmd/tailscale/cli/status.go

@@ -136,7 +136,7 @@ func runStatus(ctx context.Context, args []string) error {
 	}
 
 	var buf bytes.Buffer
-	f := func(format string, a ...interface{}) { fmt.Fprintf(&buf, format, a...) }
+	f := func(format string, a ...any) { fmt.Fprintf(&buf, format, a...) }
 	printPS := func(ps *ipnstate.PeerStatus) {
 		f("%-15s %-20s %-12s %-7s ",
 			firstIPString(ps.TailscaleIPs),

cmd/tailscale/cli/up.go

@@ -192,7 +192,7 @@ type upOutputJSON struct {
 	Error        string `json:",omitempty"` // description of an error
 }
 
-func warnf(format string, args ...interface{}) {
+func warnf(format string, args ...any) {
 	printf("Warning: "+format+"\n", args...)
 }
 
@@ -823,8 +823,8 @@ func flagAppliesToOS(flag, goos string) bool {
 	return true
 }
 
-func prefsToFlags(env upCheckEnv, prefs *ipn.Prefs) (flagVal map[string]interface{}) {
-	ret := make(map[string]interface{})
+func prefsToFlags(env upCheckEnv, prefs *ipn.Prefs) (flagVal map[string]any) {
+	ret := make(map[string]any)
 
 	exitNodeIPStr := func() string {
 		if !prefs.ExitNodeIP.IsZero() {
@@ -841,7 +841,7 @@ func prefsToFlags(env upCheckEnv, prefs *ipn.Prefs) (flagVal map[string]interfac
 		if preflessFlag(f.Name) {
 			return
 		}
-		set := func(v interface{}) {
+		set := func(v any) {
 			if flagAppliesToOS(f.Name, env.goos) {
 				ret[f.Name] = v
 			} else {
@@ -895,7 +895,7 @@ func prefsToFlags(env upCheckEnv, prefs *ipn.Prefs) (flagVal map[string]interfac
 	return ret
 }
 
-func fmtFlagValueArg(flagName string, val interface{}) string {
+func fmtFlagValueArg(flagName string, val any) string {
 	if val == true {
 		return "--" + flagName
 	}

cmd/tailscale/cli/web.go

@@ -313,7 +313,7 @@ func webHandler(w http.ResponseWriter, r *http.Request) {
 			AdvertiseExitNode bool
 			Reauthenticate    bool
 		}
-		type mi map[string]interface{}
+		type mi map[string]any
 		if err := json.NewDecoder(r.Body).Decode(&postData); err != nil {
 			w.WriteHeader(400)
 			json.NewEncoder(w).Encode(mi{"error": err.Error()})

cmd/testcontrol/testcontrol.go

@@ -46,10 +46,10 @@ type fakeTB struct {
 }
 
 func (t fakeTB) Cleanup(_ func()) {}
-func (t fakeTB) Error(args ...interface{}) {
+func (t fakeTB) Error(args ...any) {
 	t.Fatal(args...)
 }
-func (t fakeTB) Errorf(format string, args ...interface{}) {
+func (t fakeTB) Errorf(format string, args ...any) {
 	t.Fatalf(format, args...)
 }
 func (t fakeTB) Fail() {
@@ -61,17 +61,17 @@ func (t fakeTB) FailNow() {
 func (t fakeTB) Failed() bool {
 	return false
 }
-func (t fakeTB) Fatal(args ...interface{}) {
+func (t fakeTB) Fatal(args ...any) {
 	log.Fatal(args...)
 }
-func (t fakeTB) Fatalf(format string, args ...interface{}) {
+func (t fakeTB) Fatalf(format string, args ...any) {
 	log.Fatalf(format, args...)
 }
 func (t fakeTB) Helper() {}
-func (t fakeTB) Log(args ...interface{}) {
+func (t fakeTB) Log(args ...any) {
 	log.Print(args...)
 }
-func (t fakeTB) Logf(format string, args ...interface{}) {
+func (t fakeTB) Logf(format string, args ...any) {
 	log.Printf(format, args...)
 }
 func (t fakeTB) Name() string {
@@ -80,13 +80,13 @@ func (t fakeTB) Name() string {
 func (t fakeTB) Setenv(key string, value string) {
 	panic("not implemented")
 }
-func (t fakeTB) Skip(args ...interface{}) {
+func (t fakeTB) Skip(args ...any) {
 	t.Fatal("skipped")
 }
 func (t fakeTB) SkipNow() {
 	t.Fatal("skipnow")
 }
-func (t fakeTB) Skipf(format string, args ...interface{}) {
+func (t fakeTB) Skipf(format string, args ...any) {
 	t.Logf(format, args...)
 	t.Fatal("skipped")
 }