docker_run.py

#!/usr/bin/env python3
# -*- encoding: utf-8 -*-
"""
Run a Docker image used by a Make task.

This script does _not_ run inside a container, so it has to work on any
system.  This means:
 1. No third-party Python libraries!
 2. Python 2 and Python 3 compatible.

Arguments after the two flags are passed directly to ``docker run``.

"""

import argparse
import os
import subprocess
import sys

# Root of the Git repository
ROOT = (
    subprocess.check_output(["git", "rev-parse", "--show-toplevel"])
    .decode("utf8")
    .strip()
)


def _aws_credentials_args():
    """
    Returns the arguments to add to ``docker run`` for sharing AWS credentials
    with the running container.
    """
    # THE AWS_PROFILE environment allows you to run operations in a
    # non-default profile.  If you have multiple profiles in your ~/.aws
    # config, use this variable to choose a non-default profile.  For example:
    #
    #   AWS_PROFILE=platform ./docker_run.py --aws -- ...
    #
    # For details:
    # https://docs.aws.amazon.com/cli/latest/userguide/cli-multiple-profiles.html
    try:
        cmd = [
            "--env",
            "AWS_PROFILE=%s" % os.environ["AWS_PROFILE"],
            # We need this environment variable or Terraform doesn't pick up
            # the AWS_PROFILE variable.  See:
            # https://github.com/terraform-providers/terraform-provider-aws/issues/233
            "--env",
            "AWS_SDK_LOAD_CONFIG=1",
        ]
    except KeyError:
        cmd = []

    if "AWS_ACCESS_KEY_ID" in os.environ:
        print("*** Trying environment variables for AWS config...")
        cmd.extend(
            [
                "--env",
                "AWS_ACCESS_KEY_ID=%s" % os.environ.get("AWS_ACCESS_KEY_ID", ""),
                "--env",
                "AWS_SECRET_ACCESS_KEY=%s"
                % os.environ.get("AWS_SECRET_ACCESS_KEY", ""),
                "--env",
                "AWS_REGION=%s" % os.environ.get("AWS_REGION", ""),
                "--env",
                "AWS_DEFAULT_REGION=%s" % os.environ.get("AWS_DEFAULT_REGION", ""),
            ]
        )
    else:
        # If we're running this script from inside another Docker image,
        # we need to make sure we still mount the correct AWS directory
        # in the new container.
        try:
            user_dir = os.environ["USER_DIR"]
        except KeyError:
            user_dir = os.environ["HOME"]

        print("*** Missing environment variable, using ~/.aws")
        aws_path = os.path.join(user_dir, ".aws")
        cmd.extend(["--volume", "%s:/root/.aws" % aws_path])
        cmd.extend(["--env", "USER_DIR=%s" % user_dir])

    return cmd


def parse_args():
    parser = argparse.ArgumentParser(
        description="Run a Docker image used by a Make task."
    )
    parser.add_argument(
        "--aws",
        dest="share_aws_creds",
        action="store_const",
        const=True,
        help="Whether to share AWS credentials with the running container",
    )
    parser.add_argument(
        "--dind",
        dest="docker_in_docker",
        action="store_const",
        const=True,
        help="Whether to allow this container to run Docker",
    )
    parser.add_argument(
        "--sbt",
        dest="share_sbt_dirs",
        action="store_const",
        const=True,
        help="Whether to share sbt directories with the running container",
    )
    parser.add_argument(
        "--root",
        dest="expose_host_root_folder",
        action="store_const",
        const=True,
        help="Whether to expose the name of the root folder of the repository in the host",
    )
    return parser.parse_known_args()


if __name__ == "__main__":
    namespace, additional_args = parse_args()

    cmd = ["docker", "run", "--tty", "--rm"]

    if namespace.share_aws_creds:
        cmd += _aws_credentials_args()

    if namespace.expose_host_root_folder or namespace.docker_in_docker:
        cmd += ["--volume", "%s:%s" % (ROOT, ROOT)]
        cmd += ["--workdir", ROOT]

    if namespace.docker_in_docker:
        cmd += ["--volume", "/var/run/docker.sock:/var/run/docker.sock"]

    if namespace.share_sbt_dirs:
        cmd += ["--volume", "%s/.sbt:/root/.sbt" % os.environ["HOME"]]
        cmd += ["--volume", "%s/.ivy2:/root/.ivy2" % os.environ["HOME"]]

        if not namespace.share_aws_creds:
            cmd += _aws_credentials_args()

    if namespace.expose_host_root_folder:
        cmd += ["-e", "ROOT=%s" % ROOT]

    if additional_args[0] == "--":
        additional_args = additional_args[1:]
    cmd += additional_args

    try:
        print("*** Running %r" % " ".join(cmd))
        rc = subprocess.call(cmd)
        if rc != 0:
            sys.exit(rc)
    except KeyboardInterrupt:
        sys.exit(1)