How to grep kubectl output to the Jenkins variable

February 18, 2022

I have kubernetes job and I would like to get his pod logs in the jenkins pipeline.

So I try to grep pod name to the jenkins variable and then get logs.

POD_NAME = sh script: "kubectl describe jobs.batch ${JOB_NAME} | grep 'Created pod' | cut -d':' -f2"

echo "${POD_NAME}"

sh "kubectl logs --follow ${POD_NAME}"

But I got null in the POD_NAME variable.

>Solution :

I assume that your jenkins controller or agent is able to query the kubernetes api with kubectl because it has a serviceaccount or some other form of credential to access kubernetes.

If that is true, I propose that you use a label to identify the pods created by the job and to query anything related to them.

You can do that by adding a label to the .spec.metadata.labels section as shown below and then query with kubectl and the --selector flag:

---
apiVersion: batch/v1
kind: Job
metadata:
  name: MYAPP
  ...
spec:
  template:
    metadata:
      ...
      labels:
        test: value
    spec:
      containers:
      - name: MYAPP
        image: python:3.7.6-alpine3.10
        ...

kubectl logs --follow --selector test=value

Use kubectl logs --help to get further information and examples.