docker-rerun/docker-rerun

#!/usr/bin/python3

import argparse
import inspect
import json
import subprocess
import sys


def inspect_container(container):
    output = subprocess.check_output(['docker', 'inspect',
                                      '--type=container', container])
    return json.loads(output.decode('utf-8'))[0]


def handle_binds(container, config):
    if container['HostConfig']['Binds']:
        config['args'].extend(['--volume=%s' % bind
                               for bind in container['HostConfig']['Binds']])


def handle_image(container, config):
    config['image'] = container['Config']['Image']


def handle_name(container, config):
    # Trim the leading / off the name. They're equivalent from docker's point
    # of view, but having the plain name looks nicer from a human point of view.
    config['args'].append('--name=%s' % container['Name'][1:])


def handle_network_mode(container, config):
    network = container['HostConfig']['NetworkMode']
    if network != 'default':
        config['args'].append('--net=%s' % network)


def handle_ports(container, config):
    ports = container['HostConfig']['PortBindings']
    if ports:
        for port, bindings in ports.items():
            for binding in bindings:
                if binding['HostIp']:
                    config['args'].append('-p=%s:%s:%s' % (binding['HostIp'],
                                                           binding['HostPort'],
                                                           port))
                elif binding['HostPort']:
                    config['args'].append('-p=%s:%s' % (binding['HostPort'],
                                                        port))
                else:
                    config['args'].append('-p=%s' % port)


def handle_restart(container, config):
    policy = container['HostConfig']['RestartPolicy']
    if policy and policy['Name'] != 'no':
        arg = '--restart=%s' % policy['Name']
        if policy['MaximumRetryCount'] > 0:
            arg += ':%s' % policy['MaximumRetryCount']
        config['args'].append(arg)


def handle_volumes_from(container, config):
    if container['HostConfig']['VolumesFrom']:
        config['args'].extend(['--volumes-from=%s' % cont for
                               cont in container['HostConfig']['VolumesFrom']])


def functions():
    return [m for m
            in inspect.getmembers(sys.modules[__name__])
            if inspect.isfunction(m[1])]


def handlers():
    return [func for (name, func) in functions() if name.startswith('handle_')]


def main():
    parser = argparse.ArgumentParser(description='Reruns docker containers ' \
                                                 'with different parameters.')
    parser.add_argument('container', type=str, help='The container to rerun')
    parser.add_argument('-d', '--dry-run', action='store_true',
                        help='Don\'t actually re-run the container, just ' \
                             'print what would happen.')
    args = parser.parse_args()
    container = inspect_container(args.container)

    docker_config = {'args': ['-d'], 'image': ''}
    for handler in handlers():
        handler(container, docker_config)

    commands = [
        ['docker', 'stop', args.container],
        ['docker', 'rm', args.container],
        ['docker', 'run'] + docker_config['args'] + [docker_config['image']],
    ]

    if args.dry_run:
        print('Performing dry run for container %s. The following would be ' \
              'executed:' % args.container)
        for command in commands:
            print(' '.join(command))
    else:
        print('Re-running container %s...' % args.container)
        for command in commands:
            subprocess.check_call(command)


if __name__ == "__main__":
    main()