Here is a simplified example showing how we used Kubernetes Events for error reporting across distinct services. We have open sourced a [sample golang application](https://github.com/box/error-reporting-with-kubernetes-events) representative of the previously mentioned control plane service. It watches changes on CRDs and does input parameter checking. If an error is discovered, a Kubernetes Event is generated and the relevant pod’s event stream is updated.  

The sample application executes this [code](https://github.com/box/error-reporting-with-kubernetes-events/blob/master/cmd/controlplane/main.go#L201) to setup the Kubernetes Event generation:  


```
// eventRecorder returns an EventRecorder type that can be  
// used to post Events to different object's lifecycles.  
func eventRecorder(  
   kubeClient \*kubernetes.Clientset) (record.EventRecorder, error) {  
   eventBroadcaster := record.NewBroadcaster()  
   eventBroadcaster.StartLogging(glog.Infof)  
   eventBroadcaster.StartRecordingToSink(  
      &typedcorev1.EventSinkImpl{  
         Interface: kubeClient.CoreV1().Events("")})  
   recorder := eventBroadcaster.NewRecorder(  
      scheme.Scheme,  
      v1.EventSource{Component: "controlplane"})  
   return recorder, nil  
}
 ```


After the one-time setup, the following [code](https://github.com/box/error-reporting-with-kubernetes-events/blob/master/cmd/controlplane/main.go#L163) generates events affiliated with pods:  


```
ref, err := reference.GetReference(scheme.Scheme, &pod)  
if err != nil {  
   glog.Fatalf("Could not get reference for pod %v: %v\n",  
      pod.Name, err)  
}  
recorder.Event(ref, v1.EventTypeWarning, "pki ServiceName error",  
   fmt.Sprintf("ServiceName: %s in pki: %s is not found in"+  
      " allowedNames: %s", pki.Spec.ServiceName, pki.Name,  
      allowedNames))
 ```


Further implementation details can be understood by running the sample application.  

As mentioned previously, here is the relevant kubectl describe output for the application owner.  


```
Events:  
  FirstSeen   LastSeen   Count   From         SubObjectPath   Type      Reason         Message  
  ---------   --------   -----   ----         -------------   --------   ------     
  ....  
  1d      1m      24   controlplane            Warning      pki ServiceName error   ServiceName: appp1 in pki: app1-pki is not found in allowedNames: [app1 app2]  
  ....  

 ```


We have demonstrated a practical use case with Kubernetes Events. The automated feedback to programmers in the case of configuration errors has significantly improved our troubleshooting efforts. In the future, we plan to use Kubernetes Events in various other applications under similar use cases. The recently created [sample-controller](https://github.com/kubernetes/sample-controller) example also utilizes Kubernetes Events in a similar scenario. It is great to see there are more sample applications to guide the community. We are excited to continue exploring other use cases for Events and the rest of the Kubernetes API to make development easier for our engineers.  

_If you have a Kubernetes experience you’d like to share, [submit your story](https://docs.google.com/a/google.com/forms/d/e/1FAIpQLScuI7Ye3VQHQTwBASrgkjQDSS5TP0g3AXfFhwSM9YpHgxRKFA/viewform). If you use Kubernetes in your organization and want to voice your experience more directly, consider joining the [CNCF End User Community](https://www.cncf.io/people/end-user-community/) that Box and dozens of like-minded companies are part of._    

Special thanks for Greg Lyons and Mohit Soni for their contributions.