RFE: Support command to switch oc client version

[nak3]

Motivation

There are two motivations.

1. Some users have different clusters with different version. Although it is possible to switch server context by oc login, client version cannot. Since k8s/openshift supports only N±1 version, oc client sometimes incompatible.

2. During upgrade, playbook upgrade.yml executes:

   step-1. Run some pre operations with oc command like # oc adm migrate storage in pre upgrade storage .
   step-2. Update client package (e.g oc v3.7->3.9).
   step-3. Run some post operations with updated oc command like # oc adm migrate storage.

So, If playbook failed at step-3, re-running playbook from step-1 will fail due to incompatible client version.

Additional Information

One possible solution is that switching symbolic link by a script. However, the motivation #2 needs a official solution from client options or RPM package release.

[soltysh]

I don't this kind of functionality should ever be handled by oc itself. It's rather a higher level tool that would do that. Similarly to others available for switching runtime language (python, go, etc).

[aditya-konarde]

I landed here looking for exactly the same thing as @nak3 ; I do agree that this shouldn't be handled by oc itself, but instead wrapper. For example there's something along these lines available for docker: https://github.com/newrelic/dkenv

I'll try to get something up as a weekend project. Juggling multiple client versions is a pain :)