annotate contrib/packaging/hg-docker @ 41234:4c0d4bbdc395

packaging: allow running packaging with custom uid+gid for CentOS

rpmbuild in CentOS 7 has a bug causing rpmbuild to fail
with "Bad owner/group" if spec or source files are owned
by a different user: https://github.com/rpm-software-management/rpm/issues/2

This makes it very annoying to try and build the CentOS RPMs
on CentOS with Docker.

As an alternative, this change makes it possible to do so,
using an environment variable.

Differential Revision: https://phab.mercurial-scm.org/D5571

#!/usr/bin/env python3
#
# Copyright 2018 Gregory Szorc <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import argparse
import pathlib
import shutil
import subprocess
import sys

def get_docker() -> str:
    docker = shutil.which('docker.io') or shutil.which('docker')
    if not docker:
        print('could not find docker executable')
        return 1

    try:
        out = subprocess.check_output([docker, '-h'], stderr=subprocess.STDOUT)

        if b'Jansens' in out:
            print('%s is the Docking System Tray; try installing docker.io' %
                  docker)
            sys.exit(1)
    except subprocess.CalledProcessError as e:
        print('error calling `%s -h`: %s' % (docker, e.output))
        sys.exit(1)

    out = subprocess.check_output([docker, 'version'],
                                  stderr=subprocess.STDOUT)

    lines = out.splitlines()
    if not any(l.startswith((b'Client:', b'Client version:')) for l in lines):
        print('`%s version` does not look like Docker' % docker)
        sys.exit(1)

    if not any(l.startswith((b'Server:', b'Server version:')) for l in lines):
        print('`%s version` does not look like Docker' % docker)
        sys.exit(1)

    return docker

def get_dockerfile(path: pathlib.Path, args: list) -> bytes:
    with path.open('rb') as fh:
        df = fh.read()

    for k, v in args:
        df = df.replace(bytes('%%%s%%' % k.decode(), 'utf-8'), v)

    return df

def build_docker_image(dockerfile: pathlib.Path, params: list, tag: str):
    """Build a Docker image from a templatized Dockerfile."""
    docker = get_docker()

    dockerfile_path = pathlib.Path(dockerfile)

    dockerfile = get_dockerfile(dockerfile_path, params)

    print('building Dockerfile:')
    print(dockerfile.decode('utf-8', 'replace'))

    args = [
        docker,
        'build',
        '--build-arg', 'http_proxy',
        '--build-arg', 'https_proxy',
        '--tag', tag,
        '-',
    ]

    print('executing: %r' % args)
    p = subprocess.Popen(args, stdin=subprocess.PIPE)
    p.communicate(input=dockerfile)
    if p.returncode:
        raise subprocess.CalledProcessException(
                p.returncode, 'failed to build docker image: %s %s' \
                % (p.stdout, p.stderr))

def command_build(args):
    build_args = []
    for arg in args.build_arg:
        k, v = arg.split('=', 1)
        build_args.append((k.encode('utf-8'), v.encode('utf-8')))

    build_docker_image(pathlib.Path(args.dockerfile),
                       build_args,
                       args.tag)

def command_docker(args):
    print(get_docker())

def main() -> int:
    parser = argparse.ArgumentParser()

    subparsers = parser.add_subparsers(title='subcommands')

    build = subparsers.add_parser('build', help='Build a Docker image')
    build.set_defaults(func=command_build)
    build.add_argument('--build-arg', action='append', default=[],
                        help='Substitution to perform in Dockerfile; '
                             'format: key=value')
    build.add_argument('dockerfile', help='path to Dockerfile to use')
    build.add_argument('tag', help='Tag to apply to created image')

    docker = subparsers.add_parser('docker-path', help='Resolve path to Docker')
    docker.set_defaults(func=command_docker)

    args = parser.parse_args()

    return args.func(args)

if __name__ == '__main__':
    sys.exit(main())