feat: additional flag to force start manager-api (#1898)

api/cmd/root.go

@@ -43,6 +43,7 @@ import (
 
 var (
 	configFile string
+	forceStart bool
 )
 
 var rootCmd = &cobra.Command{
@@ -65,6 +66,7 @@ func init() {
 
 	rootCmd.PersistentFlags().StringVarP(&configFile, "config", "c", "./conf/conf.yml", "config file")
 	rootCmd.PersistentFlags().StringVarP(&conf.WorkDir, "work-dir", "p", ".", "current work directory")
+	rootCmd.PersistentFlags().BoolVarP(&forceStart, "force", "f", false, "force start manager-api")
 
 	rootCmd.AddCommand(
 		newVersionCommand(),
@@ -86,7 +88,7 @@ func manageAPI() error {
 	conf.InitConf()
 	log.InitLogger()
 
-	if err := utils.WritePID(conf.PIDPath); err != nil {
+	if err := utils.WritePID(conf.PIDPath, forceStart); err != nil {
 		log.Errorf("failed to write pid: %s", err)
 		return err
 	}

api/internal/utils/pid.go

@@ -25,9 +25,12 @@ import (
 )
 
 // WritePID write pid to the given file path.
-func WritePID(filepath string) error {
-	if _, err := os.Stat(filepath); err == nil {
-		return fmt.Errorf("instance of Manager API already running: a pid file exists in %s", filepath)
+func WritePID(filepath string, forceStart bool) error {
+	if pid, err := ReadPID(filepath); err == nil {
+		if !forceStart {
+			return fmt.Errorf("Instance of Manager API maybe running with a pid %d. If not, please run Manager API with '-f' or '--force' flag\n", pid)
+		}
+		fmt.Printf("Force starting new instance. Another instance of Manager API maybe running with pid %d\n", pid)
 	}
 	pid := os.Getpid()
 	f, err := os.OpenFile(filepath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC|os.O_CREATE, 0600)