Kubernetes - Testing

Unit Tests

Use a fake client: sigs.k8s.io/controller-runtime/pkg/client/fake

Integration Tests

Some of the tools to facilitate integration tests (ordered by complexity of the test cases.)

Tool	Note
kuttl	only for CRUD
envtest	only k8s API server + etcd
kind	complete k8s cluster

More details:

• kuttl: test k8s operators using only YAML (no Go code), good for CRUD testing.
  • https://kuttl.dev/
• envtest:
  • Running locally, only k8s API server + etcd; NO kubelet, controller-manager or other components.
  • Good for testing controllers.
  • Part of controller-runtime (sigs.k8s.io/controller-runtime/pkg/envtest)
• kind:
  • https://kind.sigs.k8s.io/
  • creates k8s clusters in docker.

E2E Tests

In a real or simulated environment.

E.g. functional, load & performance, disaster recovery, upgrade.