add comments for cpm

pkg/custompluginmonitor/plugin/plugin.go

@@ -93,6 +93,7 @@ func (p *Plugin) runRules() {
 	glog.V(3).Info("Start to run custom plugins")
 
 	for _, rule := range p.config.Rules {
+		// syncChan limits concurrent goroutines to configured PluginGlobalConfig.Concurrency value
 		p.syncChan <- struct{}{}
 		p.Add(1)
 		go func(rule *cpmtypes.CustomRule) {
@@ -116,6 +117,7 @@ func (p *Plugin) runRules() {
 				Message:    message,
 			}
 
+			// pipes result into resultChan which customPluginMonitor instance generates status from
 			p.resultChan <- result
 
 			// Let the result be logged at a higher verbosity level. If there is a change in status it is logged later.