capture stderr as well as stdout when diagnosing

[lepistone]

This fixes #125 because in some Ubuntu systems
lsb_release outputs to stderr as well as stdout. This message will be
printed to console, not logged nor shown among server infomation. That
way the message is lost and only pollutes unit tests output.

[pedrobaeza]

Why not subprocess.STDERR?

[lepistone]

@pedrobaeza I gave a look at the doc at https://docs.python.org/2/library/subprocess.html and subprocess.STDERR it is not a choice you can make.

In the line after, with communicate()[0] we return stdout. If we did stderr=PIPE then stderr would go to communicate()[1] but then we wouldn't use it, so it would be discarded.

What I did is to return stderr together with stdout so that is displayed by the module. The other option would be to throw it away with 2> /dev/null.

[pedrobaeza]

OK, thanks for the explanation

👍

[yvaucher]

👍

[nbessi]

👍