Support context switch for argocd-util

[galan]

Summary

I have multiple contexts I need to switch between, it would be very helpful to switch the context on a global level via an argument or environment-variable.

Motivation

Let's assume you have three contexts named dev, staging and production and are constantly changing via argocd context dev...., argocd context staging.... or argocd context production...., prior actual execution of the desired action. Also you have to check each time which context you are currently working in prior execution.

So the current workflow is:

# check which context I'm in
argocd context
# switch if required
argocd context staging...
# execute command, eg:
argocd app list

Proposal

Pass the context in the actual command, eg:

argocd app list --context staging...

or as environment variable

ARGOCD_CONTEXT=staging... argocd app list

[nekia]

I'd like to work on this issue if anyone hasn't done yet.

[crenshaw-dev]

Looks like the PR just needs a review (and probably massive rebase).

[waddles]

Looks like the PR just needs a review (and probably massive rebase).

It's a 1-line change with ~133 generated docs changes and it's already had a review.