stderr output instead of stdout for cmd test about container-structure-test

[nkubala]

Hmm, just by looking at this it seems that there are two things going on.

The first is that the output of your command is going to stderr, but the streams are definitely kept separate when attaching to the docker logs (see here), so I think this might actually a weird thing with the command you're running. Can you try running it directly in your container again and redirecting stderr to a file (command 2> stderr.txt) and see if it's printing to the wrong (or at least unexpected) stream?

The second thing is that you're using a simple matching string for the expectedOutput here, but these are actually interpreted by the testing framework as regexes. This means that to actually match the string "1.14.17", you'll need to use something like expectedOutput: [".*1\.14\.17.*"] if you expect there to be surrounding output. I know this is a bit of a weird UX, and something I'd like to improve.

[Evesy]

@goffinf What version of python do you have installed?

If you're using a python version <3.4 then aws --version will print to stderr, however more recent versions should print to stdout.

[donmccasland]

I don't think we need to alter the logic for the test infrastructure. I think there are 3 suitable workarounds for the fact that aws --version behaves in an unexpected way.

I'm going to close "won't fix," but if you disagree please reopen with discussion.