Support for using Kubernetes-SIGs Kwok cluster simulator

[vladimirvivien]

Proposal

kwok is a Kubernetes cluster simulator, from Kubernetes-SIGs, that can start fully Kubernetes API-compatible cluster. This project should investigate how e2e-framework can leverage Kwok for end-to-end testing. Currently, the project already has environment functions that can start/stop Kind. It would be useful to create environment functions to start/configure/stop kwok clusters at test time for quickstart end-to-end tests.

The following is an illustrative mock up of what that support could look like. This example would create a simulated cluster, run the tests, then teardown that cluster.

func TestMain(m *testing.M) {
	testenv = env.New()
	clusterName := envconf.RandomName("some-cluster", 16)
	namespace := envconf.RandomName("kind-ns", 16)

	testenv.Setup(
		envfuncs.CreateKwokCluster(kindClusterName),
		envfuncs.CreateNamespace(namespace),
	)

	testenv.Finish(
		envfuncs.DeleteNamespace(namespace),
		envfuncs.DestroyKwokCluster(kindClusterName),
	)
	os.Exit(testenv.Run(m))
}

References

• Kwok - https://kwok.sigs.k8s.io/
• Kwok Github - https://github.com/kubernetes-sigs/kwok

[reetasingh]

@ vladimirvivien I am interested in working on this feature.

[wzshiming]

I am happy to see that the e2e-framework will support kwok 🎉🎉🎉

I have a small requirement, I want to refactor e2e for kwok/kwokctl with e2e-framework, and I need e2e-framework to be able to support modifications to the kwokctl dependency version, rather than like the kind version.

[harshanarayana]

@wzshiming The kind version is configurable too. Just that it also defaults to a specific version

e2e-framework/support/kind/kind.go

Lines 45 to 48 in 06323f4

	func (k *Cluster) WithVersion(ver string) *Cluster {
	k.version = ver
	return k
	}

cluster := kind.NewCluster(name)
cluster.WithVersion("0.24.0")
kubeconfig, err := cluster.Create()
// do things after

[wzshiming]

@wzshiming The kind version is configurable too. Just that it also defaults to a specific version

e2e-framework/support/kind/kind.go

Lines 45 to 48 in 06323f4

	func (k *Cluster) WithVersion(ver string) *Cluster {
	k.version = ver
	return k
	}

cluster := kind.NewCluster(name)
cluster.WithVersion("0.24.0")
kubeconfig, err := cluster.Create()
// do things after

Thank you, I see!

[vladimirvivien]

When this is done it would be like an Inception: Kwok using e2e-framework and e2e-framework supports Kwok! 🤣 Love it!

[reetasingh]

@vladimirvivien @wzshiming @harshanarayana I have opened #239 for this feature. please review. My apologies for delay in sending a PR

[wzshiming]

@vladimirvivien
I'm working on e2e of kwok and didn't find that sigs.k8s.io/e2e-framework/klient/k8s/resources has a method to update subresources(status), which is essential for kwok e2e, is it possible to add this.

[vladimirvivien]

@wzshiming Absolutely 👍 Please open a PR for contribution.