Disable cron job if in slave mode

refs SkygearIO#104

main.go

@@ -89,7 +89,10 @@ func main() {
 
 	preprocessorRegistry := router.PreprocessorRegistry{}
 
-	cronjob := cron.New()
+	var cronjob *cron.Cron
+	if !config.App.Slave {
+		cronjob = cron.New()
+	}
 	initContext := plugin.InitContext{
 		Router:           r,
 		Mux:              serveMux,
@@ -246,7 +249,6 @@ func main() {
 	}
 
 	// Bootstrap finished, starting services
-	cronjob.Start()
 	initPlugin(config, &initContext)
 
 	log.Printf("Listening on %v...", config.HTTP.Host)
@@ -392,6 +394,10 @@ func initSubscription(config skyconfig.Configuration, connOpener func() (skydb.C
 func initPlugin(config skyconfig.Configuration, initContext *plugin.InitContext) {
 	log.Infof("Supported plugin transports: %s", strings.Join(plugin.SupportedTransports(), ", "))
 
+	if initContext.Scheduler != nil {
+		initContext.Scheduler.Start()
+	}
+
 	for _, pluginConfig := range config.Plugin {
 		initContext.AddPluginConfiguration(pluginConfig.Transport, pluginConfig.Path, pluginConfig.Args)
 	}

pkg/server/plugin/plugin.go

@@ -168,11 +168,15 @@ func (p *Plugin) processRegistrationInfo(context *InitContext, regInfo registrat
 	log.WithFields(logrus.Fields{
 		"regInfo":   regInfo,
 		"transport": p.transport,
-	}).Debugln("Got configuration from pligin, registering")
+	}).Debugln("Got configuration from plugin, registering")
 	p.initHandler(context.Mux, context.Preprocessors, regInfo.Handlers)
 	p.initLambda(context.Router, context.Preprocessors, regInfo.Lambdas)
 	p.initHook(context.HookRegistry, regInfo.Hooks)
-	p.initTimer(context.Scheduler, regInfo.Timers)
+	if context.Scheduler != nil {
+		p.initTimer(context.Scheduler, regInfo.Timers)
+	} else {
+		log.Info("Ignoring scheduled cron jobs because server is in slave mode.")
+	}
 	p.initProvider(context.ProviderRegistry, regInfo.Providers)
 }