feat(cmd): add version flag (#822)

cmd/root.go

@@ -17,8 +17,14 @@ func Run() error {
 	configPath := flag.String("config-path", config.DefaultPath(), "path of the configuration file")
 	logPath := flag.String("log-path", logger.DefaultPath(), "path of the log file")
 	logLevel := flag.String("log-level", "info", "log level")
+	showVersion := flag.Bool("version", false, "print version and exit")
 	flag.Parse()
 
+	if *showVersion {
+		fmt.Printf("%s\n", buildVersion())
+		return nil
+	}
+
 	var level slog.Level
 	switch *logLevel {
 	case "debug":

cmd/version.go

@@ -0,0 +1,18 @@
+package cmd
+
+import (
+	"runtime/debug"
+)
+
+func buildVersion() string {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return "unknown"
+	}
+	switch info.Main.Version {
+	case "", "(devel)":
+		return "v0.0.0-dev"
+	default:
+		return info.Main.Version
+	}
+}