ungoogled-chromium-extension-updater.py

import argparse
import json
import os
import posixpath
import shutil
import subprocess
import tempfile

import requests

EXTENSIONS_PATH = os.path.expanduser('~/.config/chromium/Default/Extensions')
LOCAL_STATE_PATH = os.path.expanduser('~/.config/chromium/Local State')
MANIFEST_PATH_TEMPLATE = os.path.expanduser('~/.config/chromium/Default/Extensions/{id}/{version}/manifest.json')

# https://ungoogled-software.github.io/ungoogled-chromium-wiki/faq#can-i-install-extensions-from-the-chrome-webstore
CRX_URL_TEMPLATE = 'https://clients2.google.com/service/update2/crx?response=redirect&prodversion={version}&x=id%3D{id}%26installsource%3Dondemand%26uc'

argument_parser = argparse.ArgumentParser()


# Chromium 67.0.3396.87 Arch Linux
def get_installed_chromium_version():
    with open(LOCAL_STATE_PATH, 'rb') as file:
        data = json.load(file)

    return data['startup_metric']['last_startup_version']


def get_extension_ids():
    ids = set(os.listdir(EXTENSIONS_PATH))
    return ids - {'Temp'}


def get_installed_version(extension_id):
    versions = os.listdir(os.path.join(EXTENSIONS_PATH, extension_id))
    return sorted(versions, reverse=True)[0]


def check_for_update(chromium_version, extension_id, installed_version):
    crx_url = CRX_URL_TEMPLATE.format(version=chromium_version, id=extension_id)
    response = requests.get(crx_url, allow_redirects=False, stream=True)

    location = response.headers['Location']
    filename = posixpath.basename(location)
    version = os.path.splitext(filename)[0].replace('extension_', '', 1)
    if version.replace('_', '.') != installed_version.replace('_', '.'):
        return version, location


def install_update(crx_path):
    executable = shutil.which('chromium')
    subprocess.run([executable, crx_path], stderr=subprocess.DEVNULL, stdout=subprocess.DEVNULL)


def load_manifest(extension_id, version):
    path = MANIFEST_PATH_TEMPLATE.format(id=extension_id, version=version)
    with open(path, 'rb') as file:
        return json.load(file)


def main(arguments):
    chromium_version = get_installed_chromium_version()
    chromium_major_version = '.'.join(chromium_version.split('.', 2)[:-1])
    print(f'Detected Chromium version: {chromium_version} (Major: {chromium_major_version})')

    for extension_id in get_extension_ids():
        extension_version = get_installed_version(extension_id)
        manifest = load_manifest(extension_id, extension_version)
        print(f'Checking updates for extension {manifest["name"]!r} ({extension_id}) v{manifest["version"]}...')
        update = check_for_update(chromium_major_version, extension_id, extension_version)
        if not update:
            continue

        version, url = update
        print(f'Downloading update {version}: {url}...')

        fd, path = tempfile.mkstemp('.crx')
        response = requests.get(url)
        with os.fdopen(fd, 'wb') as file:
            file.write(response.content)

        print('Installing update...')
        install_update(path)


if __name__ == '__main__':
    arguments = argument_parser.parse_args()
    argument_parser.exit(main(arguments))