Add version flag

Author: rothgar

main.go

@@ -37,15 +37,23 @@ func main() {
 	help := pflag.BoolP("help", "h", false, "Print usage")
 	exitErr := pflag.BoolP("exit-with-error", "e", false, "Exit with error code if docker.sock found")
 	verbose := pflag.IntP("verbose", "v", 2, "Logging level")
+	printVersion := pflag.Bool("version", false, "Print plugin version and exit")
 
 	pflag.Parse()
 
+	var version = "development"
+
 	flag.Set("v", strconv.Itoa(*verbose))
 	if *help {
 		pflag.PrintDefaults()
 		os.Exit(0)
 	}
 
+	if *printVersion {
+		fmt.Println(version)
+		os.Exit(0)
+	}
+
 	// initialize tabwriter
 	w := new(tabwriter.Writer)