Fix: Kubernetes computer container logs

[adpg24]

On release 4350.va_0283de0d6d6 the following PR was included #1699.

The container logs were still not visible through the UI so I logged the following issue: https://issues.jenkins.io/browse/JENKINS-75787

Testing done

There were no existing unit tests, so I didn't bother creating new tests. I tested the plugin by running a minikube setup locally, must of the setup comes from the README.

• Install the Kubernetes plugin dependencies
• Copy the kubernetes.hpi file into /var/jenkins_home/plugins/
• Configure a Kubernetes cloud
• Run a Jenkins job with the podTemplate step function

This is the Jenkinsfile used for testing:

def pod = """
apiVersion: "v1"
kind: "Pod"
metadata:
spec:
  containers:
  - name: jnlp
    env:
    - name: CONTAINER_ENV_VAR
      value: jnlp
  - name: nginx
    env:
    - name: CONTAINER_ENV_VAR
      value: nginx
    image: nginx:latest
    ports:
    - containerPort: 80
"""

podTemplate(label: "container-logs", yaml: pod, idleMinutes: 10) {
	node("container-logs") {
		stage("Test container logs") {
		    script {
			echo "Hello from my pod"
		    }
		}
	}
}

Once a pod has been created I can follow the link in the console logs of the job:

Created Pod: Kubernetes kubernetes-plugin/container-logs-r0s74-vlgkd
[PodInfo] kubernetes-plugin/container-logs-r0s74-vlgkd
	Container [jnlp] waiting [ContainerCreating] No message
	Container [nginx] waiting [ContainerCreating] No message
	Pod [Pending][ContainersNotReady] containers with unready status: [jnlp nginx]
Agent container-logs-r0s74-vlgkd is provisioned from template container-logs-r0s74

The container logs can now be viewed from the UI. The screenshot below shows the JNLP container logs.

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests that demonstrate the feature works or the issue is fixed

[Vlatombe]

There were no existing unit tests

Since this regressed, now is probably a good time to introduce such tests!