For the existing functionality, We have Pod Retention policies as given below:

• never
• always
• On failure
• default

All these above retention policies have been designed on the basis of status of the POD.
But when it  comes to retain a pod on the basis of status of the build, We are not having any way to retain a pod for sometime and debug the issue that might have caused the failure of the Job.

Hence, I am trying to implement a solution( a new retention policy "onJobFailure"  ) which will check the status of the last executed build on the dynamic node and will return the result of the run, based on which if it comes out to be a FAILURE, We can retain a pod and if it has been SUCCESS, We can go on to delete the pod. 
 
Implementation queries:

While trying to implement the solution, I tried to fetch the Status of the last executed job from the plugin code!

I followed 2 approaches:

1.) Using Computer method ( toComputer )  
As KubernetesSlave.java is having toComputer() and the below function, 

public PodRetention getPodRetention(KubernetesCloud cloud) {
    PodRetention retentionPolicy = cloud.getPodRetention();
    PodTemplate template = getTemplateOrNull();
    if (template != null) {
        PodRetention pr = template.getPodRetention();
        if(pr instanceof OnJobFailure){
            ((OnJobFailure) pr).setComputer(toComputer());
        }  

is deciding the pod retention policy, I used it to refer my new OnJobFailure.java class which have the inherited method, shouldDeletePod(), where I am getting the status of the last build ran on that computer, ( say computer.getBuilds().getLastBuild().getResult().equals(Result.FAILURE) )

But Somehow, getLastBuild() never returned anything.

2.) Using Jenkins Object

I tried to fetch the result as follows,

public boolean shouldDeletePod(KubernetesCloud cloud, Pod pod) {
     
        Jenkins jenkins = Jenkins.getInstanceOrNull();
        if(jenkins!= null){
          List<Job> jobs = jenkins.getItems(Job.class); // This worked and returned the list of jobs which are present in that jenkins
          if( jobs!= null) {
            Result result = jobs.get(2).getLastBuild().getResult(); // Used (2) to fetch the kubernetes job result specifically
              if (result!=null && result.equals(Result.FAILURE)) {
                  return false;
              }
            }
          }
    return true;  

With this approach, I am having the list of all the jobs in list<Job>jobs, but there is no way I can be specific about my run and if I don't have the exact build, I will not be able to fetch the status of the job.
 
I tried to search the plugin code as well, Is there any specific technical reason why we have not used anywhere the build status in the Kubernetes Plugin code ?