kola: remove legacy kubernetes test

[tormath1]

These tests are now deprecated due to the stabilization of Docker >= 20.10.

[krnowak]

Is there a way to make those tests compatible with docker 20.10? Or is this pointless?

[tormath1]

Is there a way to make those tests compatible with docker 20.10? Or is this pointless?

@krnowak that's indeed a good question - kubernetes tests are now superseded by kubeadm one, which rely directly on docker container runtime and test more up-to-date Kubernetes maintained versions (1.21, 1.22 and soon 1.23)

[krnowak]

So these kubernetes tests were testing more-or-less the same thing as the new kubeadm tests? So bumping the kubernetes versions to actively supported ones in kubernetes test would result in a some kind of duplication? If that would be so, then I think it's fine to drop the tests.

[tormath1]

@krnowak that's right.

Currently with kubernetes tests, we are testing the following versions:
https://github.com/flatcar-linux/mantle/blob/6336d5f143909cc080b95c4c4826b383ff3ac0c0/kola/tests/kubernetes/basic.go#L31-L36

While with kubeadm we are testing¹:

• v1.22.0
• v1.21.0

On top of different tested versions, we can also mention that:

• we test calico, flannel and cilium CNIs with kubeadm
• as mentioned in the name kubeadm tests deploy Kubernetes using kubeadm

Footnotes

1. https://github.com/flatcar-linux/mantle/blob/flatcar-master/kola/tests/kubeadm/kubeadm.go#L46-L69 ↩

[krnowak]

Alright, let's drop the tests.

Also, I had a look at https://endoflife.date/kubernetes and I was wondering if kubeadm tests should also test version 1.20. But probably no point in it, as its active support expires in one month, and maintenance in 3. Also, different PR for it anyway.