fix: the terminal opens in the user's home directory, not in /

internal/agent/terminal.go

@@ -20,8 +20,16 @@ type PTY struct {
 // `su -l`, which only a root agent can do without a password.
 func StartPTY(user string) (*PTY, error) {
 	var cmd *exec.Cmd
+	env := append(os.Environ(), "TERM=xterm-256color")
 	if user == "" || user == currentUser() {
 		cmd = exec.Command(defaultShell(), "-l")
+		// A login shell does not change directory by itself: it would start
+		// where the service runs, "/". Start it at home, and say where home
+		// is, as a root service often has no $HOME.
+		if home := homeDir(""); isDir(home) {
+			cmd.Dir = home
+			env = append(env, "HOME="+home)
+		}
 	} else {
 		if !validUserName(user) {
 			return nil, fmt.Errorf("недопустимое имя пользователя %q", user)
@@ -37,8 +45,13 @@ func StartPTY(user string) (*PTY, error) {
 			return nil, fmt.Errorf("su не найден: %w", err)
 		}
 		cmd = exec.Command(su, "-l", user)
+		// su -l goes to the user's home; starting there too keeps the shell
+		// out of "/" should it not.
+		if home := homeDir(user); isDir(home) {
+			cmd.Dir = home
+		}
 	}
-	cmd.Env = append(os.Environ(), "TERM=xterm-256color")
+	cmd.Env = env
 	f, err := pty.Start(cmd)
 	if err != nil {
 		return nil, err
@@ -46,6 +59,11 @@ func StartPTY(user string) (*PTY, error) {
 	return &PTY{cmd: cmd, f: f}, nil
 }
 
+func isDir(p string) bool {
+	info, err := os.Stat(p)
+	return err == nil && info.IsDir()
+}
+
 // Read reads terminal output.
 func (p *PTY) Read(b []byte) (int, error) { return p.f.Read(b) }