fix: do not fetch service account if it's unneeded

[sleshchenko]

What does this PR do?

This PR is made as a result of the following discussion #257 (comment)

Do not fetch the service account if it's unneeded. See attachments:
before:

After:
minishift-addon

operator

It also improves error message when the current context is not set:
before

now

I did not check it on an installation where healthz endpoint requires token since I do not know when to find it or how to set up, like even secure OSIO installation have healthz as public https://console.starter-us-east-2.openshift.com/healthz

It's like an unplanned quick fix, and some things can be done not in the best way. So, I'm open to proposals related to refactoring or messages.

What issues does this PR fix or reference?

Fixes eclipse-che/che#14534

It partially fixes(there are still may be places that should be addressed) eclipse-che/che#14665

How to test it?

Here are built chectl(based on the master 25.10.2019) that can be used for testing:
https://dropmefiles.com/lVXSh <- Click more to select only package specific to your OS

[benoitf]

Amazon EC2 has secured healthz

[sleshchenko]

@benoitf yeah, thanks. It's in your issue but I missed this.
Do you happen to have EC2 K8s running to check my changes?

[benoitf]

@sleshchenko no sorry my trial account has expired :-/

[sleshchenko]

@richardmward I see your issue where you use EC2 K8s for deploying of Che.
Could you please help me to test my PR?
It could be enough if you:

1. Download archive for your OS https://dropmefiles.com/lVXSh
2. Unpack it
3. rm -rf $HOME/.local/share/chectl/client to avoid cache conflicts with your installed version.
4. From unpacked folder execute ./bin/chectl server:stop --chenamespace=non-existing
   if you get

serg@localhost:~/projects/chectl$ chectl server:stop --chenamespace non-existing
  ✔ Verify Kubernetes API...OK (it's OpenShift)
  ✔ Verify if Che is deployed into namespace "non-existing"...it is not
  ✖ Deployment doesn't exist

If you get another error - probably something is wrong in my fix and let me know.

After testing you're able just remove downloaded files and also do rm $HOME/.local/share/chectl/client again. After that you're able to use your installed chectl version again.

Thanks in advance!!!

[tolusha]

Closed in favor of
#524