Updating kubernetes api version to support the latest apps/v1 version

[r1sharma]

This PR is fix related to the issue #63 & #62 . A part of these issues have been already addressed in Pull request : #53

Changes include:

• Updated chaosk8s\actions.py & chaosk8s\probes.py
• Updated related tests too.

[codecov-io]

Codecov Report

Merging #65 into master will not change coverage.
The diff coverage is n/a.

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##           master      #65   +/-   ##
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  Coverage   77.23%   77.23%           
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  Files           4        4           
  Lines         325      325           
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  Hits          251      251           
  Misses         74       74

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[Lawouach]

Good call.

A few questions:

• could you please add a changelog entry to explain why this change is needed please?
• could you try to explain what may happen for older clusters? what's the minimal version of the Kubernetes API does this work against? I've seen the go code making a call first to the new endpoint and, when it fails, falling back to the old API. should we follow the same path?

I'm surprised tests weren't impacted. maybe we are missing some...

[r1sharma]

@Lawouach Sure will update this PR with changelog later today.
Please take a look at the notes here from Kubernetes on deprecated apis removed from v1.16 and future version of kubectl. I am using version 1.16+ for kubectl and chaos toolkit keeps failing for that even after your fix here as current code points to apps/v1beta1.

[Lawouach]

Makes sense and your fix seems the right one. Wondering about backward compatibility.

[r1sharma]

previous version of chaosk8s will be compatible. right?

[Lawouach]

True although this isn't my philosophy here. But, reading your link again, they mention the apps/v1 version has been around since K8S 1.9 which is "old" (with Kubernetes, 18 months is ancient times).

I might work on a change, after yours, that will try to support both by looking up the version of the server first.

[r1sharma]

Sounds good