[kubernetes] improve parsing namespaces

[pmoravec]

Handle (theoretical) cases when "kubectl get namespace" returns a line with
white characters only, and prevent IndexError to be raised.

Resolves: #1442

Signed-off-by: Pavel Moravec pmoravec@redhat.com

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[pmoravec]

This is rather improvement of theoretical situation when kubectl returns some error output like:

Error: unknown flag: --config\n\n\nExamples:\n  # List all pods in ps output format.\n  kubectl get pods\n  \n  # List all pods in ps output format with more information (such as node name).\n  kubectl get pods -o wide\n  \n..'

Then parsing the lines '\n \n' raises the exception.

[bmr-cymru]

I wonder if this might be more readable as:

    kn_output = kn['output'].splitlines()[1:]
    knsps = [n.split()[0] for n in kn_output if n and len(n.split())]

70 chars on the long line... I don't know, but that hanging if really confused my eyes for a moment on the first look.

[pmoravec]

Good point for more code clarity there, updating the PR..