chromium_updater.py

from __future__ import with_statement
import shutil, plistlib, urllib2, re, tempfile
from os.path import join, exists, expanduser
from subprocess import call

SEARCH_FOLDERS = ('/Applications', '~/Applications')
BASE_URL = "http://build.chromium.org/buildbot/snapshots/chromium-rel-mac/"
DOWNLOAD_FORMAT = BASE_URL + "%s/chrome-mac.zip"
DEFAULT_INSTALLATION_PATH = '/Applications'

def get_version(path):
    infofile = join(path, "Contents", "Info.plist")
    return int(plistlib.readPlist(infofile)['SVNRevision'])
    
def get_latest_version():
    line_re = re.compile(r'<a href="(\d+)\/">.*<\/a>')
    rev = None
    for line in urllib2.urlopen(BASE_URL):
        mo = line_re.search(line)
        if mo is not None:
            rev = int(mo.group(1))
    return rev


chromium_app = None
install_path = None
previous_version = None
latest_version = None

for path in SEARCH_FOLDERS:
    cpath = expanduser(join(path, 'Chromium.app'))
    if exists(cpath):
        chromium_app = cpath
        install_path = path
        previous_version = get_version(cpath)
if install_path is None:
    install_path = DEFAULT_INSTALLATION_PATH
    
latest_version = get_latest_version()
if latest_version is None:
    raise RuntimeError, "Couldn't determine latest revision from the server"
if previous_version is None or previous_version < latest_version:
    print "New revision to be installed: %d" % (latest_version,)
    url = DOWNLOAD_FORMAT % (latest_version,)
    tempdir = tempfile.mkdtemp()
    print "Downloading %s into %s" % (url, tempdir,)
    try:
        call('curl %(url)s > %(tempdir)s/chrome-mac.zip && cd %(tempdir)s && unzip chrome-mac.zip' % {
            'tempdir': tempdir, 'url': url
        }, shell=True)
        if (chromium_app is not None):
            shutil.rmtree(chromium_app)
        shutil.move('%s/chrome-mac/Chromium.app' % tempdir, install_path)
    finally:
        shutil.rmtree(tempdir)
else:
    print "You're already up-to-date"