create-channel-switch-mar.py

#!/usr/bin/env python3

# create-channel-switch-mar.py
#
# for channel switching, replacing channel-prefs.js and/or update-settings.ini

import logging
from os import path, makedirs, getcwd, chdir
from shutil import rmtree
import subprocess
import tempfile


CHANNEL_PREFS = "default/pref/channel-prefs.js"
CHANNEL_PREFS_CONTENT = """\
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

pref("app.update.channel", "%s");
"""
UPDATE_SETTINGS = "update-settings.ini"
UPDATE_SETTINGS_CONTENT = """\
; If you modify this file updates may fail.
; Do not modify this file.

[Settings]
ACCEPTED_MAR_CHANNEL_IDS=%s
"""


def compress(str):
    return subprocess.check_output(["xz"], input=str.encode("ascii"))


def setup_newfiles(channel=None, accepted_mar_channel_ids=None):
    files = []
    if channel is not None:
        makedirs(path.dirname(CHANNEL_PREFS))
        makedirs("Contents/Resources/" + path.dirname(CHANNEL_PREFS))
        channel_prefs = compress(CHANNEL_PREFS_CONTENT % channel)
        logging.info("Writing %s", CHANNEL_PREFS)
        with open(CHANNEL_PREFS, "wb") as f:
            f.write(channel_prefs)
        with open("Contents/Resources/" + CHANNEL_PREFS, "wb") as f:
            f.write(channel_prefs)
        files += [CHANNEL_PREFS, "Contents/Resources/" + CHANNEL_PREFS]
    if accepted_mar_channel_ids is not None:
        makedirs("Contents/Resources/" + path.dirname(UPDATE_SETTINGS))
        update_settings = compress(
            UPDATE_SETTINGS_CONTENT % ",".join(accepted_mar_channel_ids)
        )
        logging.info("Writing %s", UPDATE_SETTINGS)
        with open(UPDATE_SETTINGS, "wb") as f:
            f.write(update_settings)
        with open("Contents/Resources/" + UPDATE_SETTINGS, "wb") as f:
            f.write(update_settings)
        files += [UPDATE_SETTINGS, "Contents/Resources/" + UPDATE_SETTINGS]
    return files


def write_manifest(files):
    manifest = 'type "partial"\n'
    for filename in files:
        manifest += 'add-if "%s" "%s"\n' % (filename, filename)
    logging.info("Writing manifest")
    with open("updatev3.manifest", "wb") as f:
        f.write(compress(manifest))
    files.append("updatev3.manifest")


def pack_mar(tmpdir, output, version, channel, files):
    logging.info("Packing mar file")
    subprocess.check_call(
        ["mar", "-C", tmpdir, "-c", output, "-V", version, "-H", channel] + files
    )


if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser()
    # contents
    parser.add_argument("-c", "--channel", help="update channel to switch to")
    parser.add_argument(
        "-i", "--accepted-channel-id", nargs="+", help="accepted mar channel id"
    )
    # metadata
    parser.add_argument(
        "-V", "--version", required=True, help="version number to use for the mar file"
    )
    parser.add_argument(
        "-m",
        "--mar-channel-id",
        required=True,
        help="channel id to use for the mar file",
    )

    parser.add_argument("-o", "--output", required=True, help="output file name")
    parser.add_argument("-v", "--verbose", action="store_true", help="verbose messages")

    args = parser.parse_args()

    log_level = logging.INFO
    if args.verbose:
        log_level = logging.DEBUG
    logging.basicConfig(
        level=log_level, format="%(asctime)s - %(levelname)s: %(message)s"
    )
    log = logging.getLogger()

    tmpdir = tempfile.mkdtemp()
    logging.info("Working directory: %s", tmpdir)

    cwd = getcwd()
    chdir(tmpdir)
    files = setup_newfiles(args.channel, args.accepted_channel_id)
    write_manifest(files)
    chdir(cwd)
    pack_mar(tmpdir, args.output, args.version, args.mar_channel_id, files)
    rmtree(tmpdir)

    log.info("All done.")

proclient-channel-switch.md

Today's pine nightly_desktop:

• accepted mar channel ids: firefox-mozilla-central
• mar channel id: firefox-mozilla-central
• update channel: nightly-pine
• product / app name: Firefox

Today's pine nightly_pinebuild:

• accepted mar channel ids: firefox-mozilla-central-pine
• mar channel id: firefox-mozilla-central-pine
• update channel: nightly-pine
• product / app name: Firefox

We need to patch update-settings.ini to accept mars with the firefox-mozilla-central-pine channel id.

$ python3 ./create-channel-switch-mar.py -i firefox-mozilla-central-pine -V 95.0a1 -m firefox-mozilla-central -o switch-to-pine.mar
2021-10-26 13:52:09,550 - INFO: Working directory: /tmp/tmp2d56wsr9
2021-10-26 13:52:09,555 - INFO: Writing update-settings.ini
2021-10-26 13:52:09,555 - INFO: Writing manifest
2021-10-26 13:52:09,559 - INFO: Packing mar file
2021-10-26 13:52:09,634 - INFO: All done.
$ mar -T switch-pine.mar 
Compression type: xz
Signature type: unknown
Signature block found with 0 signatures

1 additional block found:
  - Product Information Block:
    - MAR channel name: firefox-mozilla-central
    - Product version: 95.0a1

SIZE    MODE    NAME   
184     0644    update-settings.ini
184     0644    Contents/Resources/update-settings.ini
140     0644    updatev3.manifest

Unsigned mar uploaded to bug 1737802