Fake client behaviour when mocking k8s for testing

Question

I am using the fake clientset to perform some mocking in a k8s cli tool I am creating.

Therefore I am creating a Job resource

jobs := clientset.BatchV1().Jobs(mynamespace)
_, err = jobs.Create(context.TODO(), job, metav1.CreateOptions{})

The clienset has been created as follows:

clientset := testclient.NewSimpleClientset()

where

testclient "k8s.io/client-go/kubernetes/fake"

The job seems to be created, i.e. err is nil on the call above.

I then (from another function call) try to list the corresponding pods (using the exact same clientset)

podList, err = clientset.CoreV1().Pods(myNamespace).List(context.TODO(), labelOptions)

However the length of the corresponding list is always zero

len(podList.Items) = 0

Shouldn't the call using the fake clienset create all related mock resources? (such as the job's pod)

Answer 1

Shouldn't the call using the fake clienset create all related mock resources? (such as the job's pod)

No, the fake clientset does nothing except put objects into cache. In a real kubernetes cluster, JobController reconciles jobs and creates pods.

I suggest you testing in a real kubernetes cluster, such as K3s.