refactor: simplify service installation process

internal/cli/elevate.go

@@ -0,0 +1,57 @@
+package cli
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"runtime"
+
+	"gitea.epss.net.cn/klesh/ss/internal/storage"
+)
+
+// ensureRoot re-execs the current command under sudo if it isn't already
+// running as root. It resolves the config directory *before* elevating and
+// passes it through explicitly as SF_CONFIG_DIR, because sudo resets $HOME
+// to /root's — without this, the elevated process would silently resolve
+// the default config directory under /root instead of the invoking user's
+// home.
+//
+// Windows is handled separately: UAC elevation launches a new process that
+// can't transparently inherit the current console, so internal/service's
+// runAsAdmin instead prints manual elevation instructions rather than
+// auto-elevating.
+func ensureRoot() error {
+	if runtime.GOOS == "windows" {
+		return nil
+	}
+	if os.Geteuid() == 0 {
+		return nil
+	}
+
+	s, err := storage.New()
+	if err != nil {
+		return fmt.Errorf("failed to resolve config directory: %w", err)
+	}
+
+	self, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("failed to determine executable path: %w", err)
+	}
+
+	sudoPath, err := exec.LookPath("sudo")
+	if err != nil {
+		return fmt.Errorf("this command requires root privileges, but sudo was not found on PATH: %w", err)
+	}
+
+	args := append([]string{"env", "SF_CONFIG_DIR=" + s.ConfigDir, self}, os.Args[1:]...)
+	cmd := exec.Command(sudoPath, args...)
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	runErr := cmd.Run()
+	if cmd.ProcessState != nil {
+		os.Exit(cmd.ProcessState.ExitCode())
+	}
+	return fmt.Errorf("failed to re-exec under sudo: %w", runErr)
+}