MDBF-991 - Obtain failed test results and the associated output from MTR

[RazvanLiviuVarzaru]

Client side implementation of the MTR reporter.
Follow along commit messages for implementation details.

[fauust]

Looks good!
Some bash comments.

The syntax in bash for comparing integer should be if ((var != 0)) instead of if [[ $var -ne 0 ]]. It seems to me that this is much more close from what other languages do and someone not familiar with shell or bash would understand it easier. Also this is what https://google.github.io/styleguide/shellguide.html#testing-strings recommends which is a very good guide.

I am wondering if we should not use getopts for arguments, instead of positional arguments, the later seems more confusing and error prone to me (but maybe more complex to call from BB python?).

Finally, you should probably have an error function since error should go to STDERR, see https://github.com/MariaDB/buildbot/blob/dev/scripts/bash_lib.sh#L37-L41.

Those are not mandatory changes of course but nice to have I think.

[RazvanLiviuVarzaru]

Thanks @fauust for the review! See: 68ceebd
About getops, might be a bit more complex to call it like that from bb python code, nothing impossible.
I don't expect the positional arguments of these scripts to change often.

PS: I cannot source the functions because the code is injected into a python string. The advantage is that the scripts are very portable, the disadvantage is obvious.
Is it not something I want to fix now but to keep in mind.