Check if you're running inside a Docker container in Python

runningInDocker.py

def runningInDocker():
    with open('/proc/self/cgroup', 'r') as procfile:
        for line in procfile:
            fields = line.strip().split('/')
            if fields[1] == 'docker':
                return True

    return False

Sometimes fields[1] is reported as 'docker-ce' and fields=['13:name=systemd:', 'docker-ce', 'docker', 'blah']
Should we instead use:

            if 'docker' in fields:
                return True

Does this work on Windows? Don't have a Windows machine handy to test.