src/tests/end_to_end/package_manager/gather_package_deps.py

#!/usr/bin/env python3.8
# Copyright 2020 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import argparse
import io
import json
import os
import re
import shutil
import sys
import tarfile


class GatherPackageDeps:
    """Helper class to take a `package_manifest.json` and copy all files referenced
    into an archive that will then be available at runtime.

    Args:
      package_json (string): Path to the package's `package_manifest.json` file.
      meta_far (string): Path to the package's `meta.far` file.
      depfile (string): Path to the depfile to write to.

    Raises: ValueError if any parameter is empty.
    """

    def __init__(self, package_json, meta_far, output_tar, depfile):
        if package_json and os.path.exists(package_json):
            self.package_json = package_json
        else:
            raise ValueError('package_json must be to a valid file')

        if meta_far and os.path.exists(meta_far):
            self.meta_far = meta_far
        else:
            raise ValueError('meta_far must be to a valid file')

        if output_tar:
            self.output_tar = output_tar
        else:
            raise ValueError('output_tar cannot be empty')

        if depfile:
            self.depfile = depfile
        else:
            raise ValueError('depfile cannot be empty')

    def parse_package_json(self):
        manifest_paths = []
        with open(self.package_json) as f:
            data = json.load(f)
            for file in data['blobs']:
                if file['path'].startswith('meta/'):
                    continue
                manifest_paths.append((file['path'], file['source_path']))
        return manifest_paths

    def create_archive(self, manifest_paths):
        # Explicitly use the GNU_FORMAT because the current dart library
        # (v.3.0.0) does not support parsing other tar formats that allow for
        # filenames longer than 100 characters.
        with tarfile.open(self.output_tar, 'w',
                          format=tarfile.GNU_FORMAT) as tar:
            # Follow symlinks
            tar.dereference = True
            # Create package.manifest in memory and add it to archive.
            manifest_lines = []
            # Add all source files to archive and add manfiest lines.
            for (archive_path, source_path) in manifest_paths:
                tar.add(source_path, arcname=archive_path)
                manifest_lines.append(f'{archive_path}={archive_path}')

            # Add meta.far to archive and insert corresponding manfiest line.
            tar.add(self.meta_far, arcname='meta.far')
            manifest_lines.append('meta/package=meta.far\n')

            with io.BytesIO('\n'.join(manifest_lines).encode()) as manifest:
                tarinfo = tarfile.TarInfo('package.manifest')
                tarinfo.size = len(manifest.getvalue())
                tar.addfile(tarinfo, fileobj=manifest)

    def run(self):
        manifest_paths = self.parse_package_json()
        self.create_archive(manifest_paths)
        with open(self.depfile, 'w') as f:
            f.write(
                "{}: {}\n".format(
                    self.output_tar, ' '.join(
                        os.path.relpath(source_path)
                        for (_, source_path) in manifest_paths)))


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        '--package_json',
        required=True,
        help=
        'The path to the package_manifest.json generated by a `fuchsia_package`.'
    )
    parser.add_argument(
        '--meta_far', required=True, help="The path to the package's meta.far.")
    parser.add_argument(
        '--output_tar', required=True, help='The path to the output archive.')
    parser.add_argument(
        '--depfile',
        required=True,
        help='The path to write a depfile, see depfile from GN.',
    )
    args = parser.parse_args()

    gatherer = GatherPackageDeps(
        args.package_json, args.meta_far, args.output_tar, args.depfile).run()

    return 0


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