cmd/tailscale,feature/featuretags: make webbrowser and colorable deps omittable

Add new "webbrowser" and "colorable" feature tags so that the
github.com/toqueteos/webbrowser and mattn/go-colorable packages
can be excluded from minbox builds.

Updates #12614

Change-Id: Iabd38b242f5a56aa10ef2050113785283f4e1fe8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

cmd/tailscale/cli/cli.go

@@ -21,8 +21,6 @@ import (
 	"text/tabwriter"
 	"time"
 
-	"github.com/mattn/go-colorable"
-	"github.com/mattn/go-isatty"
 	"github.com/peterbourgon/ff/v3/ffcli"
 	"tailscale.com/client/local"
 	"tailscale.com/cmd/tailscale/cli/ffcomplete"
@@ -484,20 +482,6 @@ func countFlags(fs *flag.FlagSet) (n int) {
 	return n
 }
 
-// colorableOutput returns a colorable writer if stdout is a terminal (not, say,
-// redirected to a file or pipe), the Stdout writer is os.Stdout (we're not
-// embedding the CLI in wasm or a mobile app), and NO_COLOR is not set (see
-// https://no-color.org/). If any of those is not the case, ok is false
-// and w is Stdout.
-func colorableOutput() (w io.Writer, ok bool) {
-	if Stdout != os.Stdout ||
-		os.Getenv("NO_COLOR") != "" ||
-		!isatty.IsTerminal(os.Stdout.Fd()) {
-		return Stdout, false
-	}
-	return colorable.NewColorableStdout(), true
-}
-
 type commandDoc struct {
 	Name        string
 	Desc        string

cmd/tailscale/cli/colorable.go

@@ -0,0 +1,28 @@
+// Copyright (c) Tailscale Inc & contributors
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !ts_omit_colorable
+
+package cli
+
+import (
+	"io"
+	"os"
+
+	"github.com/mattn/go-colorable"
+	"github.com/mattn/go-isatty"
+)
+
+// colorableOutput returns a colorable writer if stdout is a terminal (not, say,
+// redirected to a file or pipe), the Stdout writer is os.Stdout (we're not
+// embedding the CLI in wasm or a mobile app), and NO_COLOR is not set (see
+// https://no-color.org/). If any of those is not the case, ok is false
+// and w is Stdout.
+func colorableOutput() (w io.Writer, ok bool) {
+	if Stdout != os.Stdout ||
+		os.Getenv("NO_COLOR") != "" ||
+		!isatty.IsTerminal(os.Stdout.Fd()) {
+		return Stdout, false
+	}
+	return colorable.NewColorableStdout(), true
+}

cmd/tailscale/cli/colorable_omit.go

@@ -0,0 +1,12 @@
+// Copyright (c) Tailscale Inc & contributors
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build ts_omit_colorable
+
+package cli
+
+import "io"
+
+func colorableOutput() (w io.Writer, ok bool) {
+	return Stdout, false
+}

cmd/tailscale/cli/open_browser.go

@@ -0,0 +1,12 @@
+// Copyright (c) Tailscale Inc & contributors
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !ts_omit_webbrowser
+
+package cli
+
+import "github.com/toqueteos/webbrowser"
+
+func init() {
+	hookOpenURL.Set(webbrowser.Open)
+}

cmd/tailscale/cli/status.go

@@ -18,7 +18,6 @@ import (
 	"text/tabwriter"
 
 	"github.com/peterbourgon/ff/v3/ffcli"
-	"github.com/toqueteos/webbrowser"
 	"golang.org/x/net/idna"
 	"tailscale.com/feature"
 	"tailscale.com/ipn"
@@ -113,7 +112,9 @@ func runStatus(ctx context.Context, args []string) error {
 			ln.Close()
 		}()
 		if statusArgs.browser {
-			go webbrowser.Open(statusURL)
+			if f, ok := hookOpenURL.GetOk(); ok {
+				go f(statusURL)
+			}
 		}
 		err = http.Serve(ln, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			if r.RequestURI != "/" {
@@ -252,6 +253,8 @@ func runStatus(ctx context.Context, args []string) error {
 	return nil
 }
 
+var hookOpenURL feature.Hook[func(string) error]
+
 var hookPrintFunnelStatus feature.Hook[func(context.Context)]
 
 // isRunningOrStarting reports whether st is in state Running or Starting.

cmd/tailscaled/depaware-minbox.txt

@@ -21,8 +21,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         github.com/klauspost/compress/internal/snapref               from github.com/klauspost/compress/zstd
         github.com/klauspost/compress/zstd                           from tailscale.com/util/zstdframe
         github.com/klauspost/compress/zstd/internal/xxhash           from github.com/klauspost/compress/zstd
-        github.com/mattn/go-colorable                                from tailscale.com/cmd/tailscale/cli
-        github.com/mattn/go-isatty                                   from github.com/mattn/go-colorable+
+        github.com/mattn/go-isatty                                   from tailscale.com/util/prompt
      💣 github.com/mdlayher/netlink                                  from github.com/jsimonetti/rtnetlink+
      💣 github.com/mdlayher/netlink/nlenc                            from github.com/jsimonetti/rtnetlink+
      💣 github.com/mdlayher/socket                                   from github.com/mdlayher/netlink
@@ -38,7 +37,6 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         github.com/tailscale/wireguard-go/rwcancel                   from github.com/tailscale/wireguard-go/device+
         github.com/tailscale/wireguard-go/tai64n                     from github.com/tailscale/wireguard-go/device
      💣 github.com/tailscale/wireguard-go/tun                        from github.com/tailscale/wireguard-go/device+
-        github.com/toqueteos/webbrowser                              from tailscale.com/cmd/tailscale/cli
      💣 go4.org/mem                                                  from tailscale.com/control/controlbase+
         go4.org/netipx                                               from tailscale.com/ipn/ipnlocal+
         tailscale.com                                                from tailscale.com/version

cmd/tailscaled/deps_test.go

@@ -295,6 +295,8 @@ func TestMinTailscaledWithCLI(t *testing.T) {
 			"archive/tar":                            "unexpected archive/tar dep",
 			"tailscale.com/feature/conn25":           "unexpected conn25 dep",
 			"regexp":                                 "unexpected regexp dep; bloats binary",
+			"github.com/toqueteos/webbrowser":        "unexpected webbrowser dep with ts_omit_webbrowser",
+			"github.com/mattn/go-colorable":          "unexpected go-colorable dep with ts_omit_colorable",
 		},
 	}.Check(t)
 }