Use dynamic pushgateway url (#614)

Fixes: stashed/stash#596

root.go

@@ -50,6 +50,7 @@ func NewRootCmd() *cobra.Command {
 	rootCmd.PersistentFlags().AddGoFlagSet(flag.CommandLine)
 	// ref: https://github.com/kubernetes/kubernetes/issues/17162#issuecomment-225596212
 	flag.CommandLine.Parse([]string{})
+	rootCmd.PersistentFlags().StringVar(&util.ServiceName, "service-name", "stash-operator", "Stash service name.")
 	rootCmd.PersistentFlags().BoolVar(&util.EnableAnalytics, "enable-analytics", util.EnableAnalytics, "Send analytical events to Google Analytics")
 	rootCmd.PersistentFlags().BoolVar(&api.EnableStatusSubresource, "enable-status-subresource", api.EnableStatusSubresource, "If true, uses sub resource for crds.")