client/systray: add installer for a freedesktop autostart file (#18767)

Adds freedesktop as an option for installing autostart desktop files for
starting the systray application.

Fixes #18766

Signed-off-by: Claus Lensbøl <claus@tailscale.com>

client/freedesktop/freedesktop.go

@@ -0,0 +1,43 @@
+// Copyright (c) Tailscale Inc & contributors
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Package freedesktop provides helpers for freedesktop systems.
+package freedesktop
+
+import "strings"
+
+const needsEscape = " \t\n\"'\\><~|&;$*?#()`"
+
+var escaper = strings.NewReplacer(`"`, `\"`, "`", "\\`", `$`, `\$`, `\`, `\\`)
+
+// Quote quotes according to the Desktop Entry Specification, as below:
+//
+// Arguments may be quoted in whole. If an argument contains a reserved
+// character the argument must be quoted. The rules for quoting of arguments is
+// also applicable to the executable name or path of the executable program as
+// provided.
+//
+// Quoting must be done by enclosing the argument between double quotes and
+// escaping the double quote character, backtick character ("`"), dollar sign
+// ("$") and backslash character ("\") by preceding it with an additional
+// backslash character. Implementations must undo quoting before expanding field
+// codes and before passing the argument to the executable program. Reserved
+// characters are space (" "), tab, newline, double quote, single quote ("'"),
+// backslash character ("\"), greater-than sign (">"), less-than sign ("<"),
+// tilde ("~"), vertical bar ("|"), ampersand ("&"), semicolon (";"), dollar
+// sign ("$"), asterisk ("*"), question mark ("?"), hash mark ("#"), parenthesis
+// ("(") and (")") and backtick character ("`").
+func Quote(s string) string {
+	if s == "" {
+		return `""`
+	}
+	if !strings.ContainsAny(s, needsEscape) {
+		return s
+	}
+
+	var b strings.Builder
+	b.WriteString(`"`)
+	escaper.WriteString(&b, s)
+	b.WriteString(`"`)
+	return b.String()
+}

client/freedesktop/freedesktop_test.go

@@ -0,0 +1,145 @@
+// Copyright (c) Tailscale Inc & contributors
+// SPDX-License-Identifier: BSD-3-Clause
+
+package freedesktop
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestEscape(t *testing.T) {
+	tests := []struct {
+		name, input, want string
+	}{
+		{
+			name:  "no illegal chars",
+			input: "/home/user",
+			want:  "/home/user",
+		},
+		{
+			name:  "empty string",
+			input: "",
+			want:  "\"\"",
+		},
+		{
+			name:  "space",
+			input: " ",
+			want:  "\" \"",
+		},
+		{
+			name:  "tab",
+			input: "\t",
+			want:  "\"\t\"",
+		},
+		{
+			name:  "newline",
+			input: "\n",
+			want:  "\"\n\"",
+		},
+		{
+			name:  "double quote",
+			input: "\"",
+			want:  "\"\\\"\"",
+		},
+		{
+			name:  "single quote",
+			input: "'",
+			want:  "\"'\"",
+		},
+		{
+			name:  "backslash",
+			input: "\\",
+			want:  "\"\\\\\"",
+		},
+		{
+			name:  "greater than",
+			input: ">",
+			want:  "\">\"",
+		},
+		{
+			name:  "less than",
+			input: "<",
+			want:  "\"<\"",
+		},
+		{
+			name:  "tilde",
+			input: "~",
+			want:  "\"~\"",
+		},
+		{
+			name:  "pipe",
+			input: "|",
+			want:  "\"|\"",
+		},
+		{
+			name:  "ampersand",
+			input: "&",
+			want:  "\"&\"",
+		},
+		{
+			name:  "semicolon",
+			input: ";",
+			want:  "\";\"",
+		},
+		{
+			name:  "dollar",
+			input: "$",
+			want:  "\"\\$\"",
+		},
+		{
+			name:  "asterisk",
+			input: "*",
+			want:  "\"*\"",
+		},
+		{
+			name:  "question mark",
+			input: "?",
+			want:  "\"?\"",
+		},
+		{
+			name:  "hash",
+			input: "#",
+			want:  "\"#\"",
+		},
+		{
+			name:  "open paren",
+			input: "(",
+			want:  "\"(\"",
+		},
+		{
+			name:  "close paren",
+			input: ")",
+			want:  "\")\"",
+		},
+		{
+			name:  "backtick",
+			input: "`",
+			want:  "\"\\`\"",
+		},
+		{
+			name:  "char without escape",
+			input: "/home/user\t",
+			want:  "\"/home/user\t\"",
+		},
+		{
+			name:  "char with escape",
+			input: "/home/user\\",
+			want:  "\"/home/user\\\\\"",
+		},
+		{
+			name:  "all illegal chars",
+			input: "/home/user" + needsEscape,
+			want:  "\"/home/user \t\n\\\"'\\\\><~|&;\\$*?#()\\`\"",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := Quote(tt.input)
+			if strings.Compare(got, tt.want) != 0 {
+				t.Errorf("expected %s, got %s", tt.want, got)
+			}
+		})
+	}
+}

client/systray/startup-creator.go

@@ -10,20 +10,34 @@ import (
 	"bufio"
 	"bytes"
 	_ "embed"
+	"errors"
 	"fmt"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"strings"
+
+	"tailscale.com/client/freedesktop"
 )
 
 //go:embed tailscale-systray.service
 var embedSystemd string
 
+//go:embed tailscale-systray.desktop
+var embedFreedesktop string
+
+//go:embed tailscale.svg
+var embedLogoSvg string
+
+//go:embed tailscale.png
+var embedLogoPng string
+
 func InstallStartupScript(initSystem string) error {
 	switch initSystem {
 	case "systemd":
 		return installSystemd()
+	case "freedesktop":
+		return installFreedesktop()
 	default:
 		return fmt.Errorf("unsupported init system '%s'", initSystem)
 	}
@@ -58,7 +72,7 @@ func installSystemd() error {
 
 	systemdDir := filepath.Join(configDir, "systemd", "user")
 	if err := os.MkdirAll(systemdDir, 0o755); err != nil {
-		return fmt.Errorf("failed creating systemd uuser dir: %w", err)
+		return fmt.Errorf("failed creating systemd user dir: %w", err)
 	}
 
 	serviceFile := filepath.Join(systemdDir, "tailscale-systray.service")
@@ -74,3 +88,129 @@ func installSystemd() error {
 
 	return nil
 }
+
+func installFreedesktop() error {
+	tmpDir, err := os.MkdirTemp("", "tailscale-systray")
+	if err != nil {
+		return fmt.Errorf("unable to make tmpDir: %w", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Install icon, and use it if it works, and if not change to some generic
+	// network/vpn icon.
+	iconName := "tailscale"
+	if err := installIcon(tmpDir); err != nil {
+		iconName = "network-transmit"
+		fmt.Printf("unable to install icon, continuing without: %s\n", err.Error())
+	}
+
+	// Create desktop file in a tmp dir
+	desktopTmpPath := filepath.Join(tmpDir, "tailscale-systray.desktop")
+	if err := os.WriteFile(desktopTmpPath, []byte(embedFreedesktop),
+		0o0755); err != nil {
+		return fmt.Errorf("unable to create desktop file: %w", err)
+	}
+
+	// Ensure autostart dir exists and install the desktop file
+	configDir, err := os.UserConfigDir()
+	if err != nil {
+		homeDir, err := os.UserHomeDir()
+		if err != nil {
+			return fmt.Errorf("unable to locate user home: %w", err)
+		}
+		configDir = filepath.Join(homeDir, ".config")
+	}
+
+	autostartDir := filepath.Join(configDir, "autostart")
+	if err := os.MkdirAll(autostartDir, 0o644); err != nil {
+		return fmt.Errorf("failed creating freedesktop autostart dir: %w", err)
+	}
+
+	desktopCmd := exec.Command("desktop-file-install", "--dir", autostartDir,
+		desktopTmpPath)
+	if output, err := desktopCmd.Output(); err != nil {
+		return fmt.Errorf("unable to install desktop file: %w - %s", err, output)
+	}
+
+	// Find the path to tailscale, just in case it's not where the example file
+	// has it placed, and replace that before writing the file.
+	tailscaleBin, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("failed to find tailscale binary %w", err)
+	}
+	tailscaleBin = freedesktop.Quote(tailscaleBin)
+
+	// Make possible changes to the desktop file
+	runEdit := func(args ...string) error {
+		cmd := exec.Command("desktop-file-edit", args...)
+		out, err := cmd.Output()
+		if err != nil {
+			return fmt.Errorf("cmd: %s: %w\n%s", cmd.String(), err, out)
+		}
+		return nil
+	}
+
+	edits := [][]string{
+		{"--set-key=Exec", "--set-value=" + tailscaleBin + " systray"},
+		{"--set-key=TryExec", "--set-value=" + tailscaleBin},
+		{"--set-icon=" + iconName},
+	}
+
+	var errs []error
+	desktopFile := filepath.Join(autostartDir, "tailscale-systray.desktop")
+	for _, args := range edits {
+		args = append(args, desktopFile)
+		if err := runEdit(args...); err != nil {
+			errs = append(errs, err)
+		}
+	}
+
+	if len(errs) > 0 {
+		return fmt.Errorf(
+			"failed changing autostart file, try rebooting: %w", errors.Join(errs...))
+	}
+
+	fmt.Printf("Successfully installed freedesktop autostart service to: %s\n", desktopFile)
+	fmt.Println("The service will run upon logging in.")
+
+	return nil
+}
+
+// installIcon installs an icon using the freedesktop tools. SVG support
+// is still on its way for some distros, notably missing on Ubuntu 25.10 as of
+// 2026-02-19. Try to install both icons and let the DE decide from what is
+// available.
+// Reference: https://gitlab.freedesktop.org/xdg/xdg-utils/-/merge_requests/116
+func installIcon(tmpDir string) error {
+	svgPath := filepath.Join(tmpDir, "tailscale.svg")
+	if err := os.WriteFile(svgPath, []byte(embedLogoSvg), 0o0644); err != nil {
+		return fmt.Errorf("unable to create svg: %w", err)
+	}
+
+	pngPath := filepath.Join(tmpDir, "tailscale.png")
+	if err := os.WriteFile(pngPath, []byte(embedLogoPng), 0o0644); err != nil {
+		return fmt.Errorf("unable to create png: %w", err)
+	}
+
+	var errs []error
+	installed := false
+	svgCmd := exec.Command("xdg-icon-resource", "install", "--size", "scalable",
+		"--novendor", svgPath, "tailscale")
+	if output, err := svgCmd.Output(); err != nil {
+		errs = append(errs, fmt.Errorf("unable to install svg: %s - %s", err, output))
+	} else {
+		installed = true
+	}
+	pngCmd := exec.Command("xdg-icon-resource", "install", "--size", "512",
+		"--novendor", pngPath, "tailscale")
+	if output, err := pngCmd.Output(); err != nil {
+		errs = append(errs, fmt.Errorf("unable to install png: %s - %s", err, output))
+	} else {
+		installed = true
+	}
+
+	if !installed {
+		return errors.Join(errs...)
+	}
+	return nil
+}

client/systray/tailscale-systray.desktop

@@ -0,0 +1,13 @@
+[Desktop Entry]
+Type=Application
+Version=1.0
+Name=Tailscale System Tray
+Comment=Tailscale system tray applet for managing Tailscale
+Exec=/usr/bin/tailscale systray
+TryExec=/usr/bin/tailscale
+Terminal=false
+NoDisplay=true
+StartupNotify=false
+Icon=tailscale
+Categories=Network;System;
+X-GNOME-Autostart-enabled=true

client/systray/tailscale.svg

@@ -0,0 +1,14 @@
+<svg width="252" height="252" viewBox="0 0 252 252" fill="none" xmlns="http://www.w3.org/2000/svg">
+<rect width="252" height="252" rx="63" fill="#1F1E1E"/>
+<path d="M72 144C81.9411 144 90 135.941 90 126C90 116.059 81.9411 108 72 108C62.0589 108 54 116.059 54 126C54 135.941 62.0589 144 72 144Z" fill="white"/>
+<path d="M126 144C135.941 144 144 135.941 144 126C144 116.059 135.941 108 126 108C116.059 108 108 116.059 108 126C108 135.941 116.059 144 126 144Z" fill="white"/>
+<path d="M126 198C135.941 198 144 189.941 144 180C144 170.059 135.941 162 126 162C116.059 162 108 170.059 108 180C108 189.941 116.059 198 126 198Z" fill="white"/>
+<path d="M180 144C189.941 144 198 135.941 198 126C198 116.059 189.941 108 180 108C170.059 108 162 116.059 162 126C162 135.941 170.059 144 180 144Z" fill="white"/>
+<g opacity="0.4">
+<path d="M72 198C81.9411 198 90 189.941 90 180C90 170.059 81.9411 162 72 162C62.0589 162 54 170.059 54 180C54 189.941 62.0589 198 72 198Z" fill="white"/>
+<path d="M180 198C189.941 198 198 189.941 198 180C198 170.059 189.941 162 180 162C170.059 162 162 170.059 162 180C162 189.941 170.059 198 180 198Z" fill="white"/>
+<path d="M72 90C81.9411 90 90 81.9411 90 72C90 62.0589 81.9411 54 72 54C62.0589 54 54 62.0589 54 72C54 81.9411 62.0589 90 72 90Z" fill="white"/>
+<path d="M126 90C135.941 90 144 81.9411 144 72C144 62.0589 135.941 54 126 54C116.059 54 108 62.0589 108 72C108 81.9411 116.059 90 126 90Z" fill="white"/>
+<path d="M180 90C189.941 90 198 81.9411 198 72C198 62.0589 189.941 54 180 54C170.059 54 162 62.0589 162 72C162 81.9411 170.059 90 180 90Z" fill="white"/>
+</g>
+</svg>