在docker中从python运行bash脚本的奇怪问题

Question

I have python-script, which run bash-scripts via subprocess library. I need to collect stdout and stderr to files, so I have wrapper like:

def execute_chell_script(stage_name, script): subprocess.check_output('{} &>logs/{}'.format(script, stage_name), shell=True)

And it works correct when I launch my python script on mac. But If I launch it in docker-container ( FROM ubuntu:18.04 ) I cant see any log-files. I can fix it if I use bash -c 'command &>log_file' instead of just command &>log_file inside subprocess.check_output(...) . But it looks like too much magic.

I thought about the default shell for user, which launches python-script (its root), but cat /etc/passwd shows root ... /bin/bash .

It would be nice if someone explain me what happened. And maybe I can add some lines to dockerfile to use the same python-script inside and outside docker-container?

Answer 1

As the OP reported in a comment that this fixed their problem, I'm posting it as an answer so they can accept it.

Using check_output when you don't get expect any output is weird; and requiring shell=True here is misdirected. You want

with open(os.path.join('logs', stage_name)) as output:
    subprocess.run([script], stdout=ouput, stderr=output)