Add omahaproxy.py for accessing Chrome channel information from the command line.

Review URL: https://codereview.chromium.org/11789004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@175962 0039d316-1c4b-4281-b951-d872f2087c98

tools/omahaproxy.py

+#!/usr/bin/env python
+# Copyright (c) 2013 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Chrome Version Tool
+
+Scrapes Chrome channel information and prints out the requested nugget of
+information.
+"""
+
+import json
+import optparse
+import os
+import string
+import sys
+import urllib
+
+URL = 'https://omahaproxy.appspot.com/json'
+
+
+def main():
+  try:
+    data = json.load(urllib.urlopen(URL))
+  except Exception as e:
+    print 'Error: could not load %s\n\n%s' % (URL, str(e))
+    return 1
+
+  # Iterate to find out valid values for OS, channel, and field options.
+  oses = set()
+  channels = set()
+  fields = set()
+
+  for os_versions in data:
+    oses.add(os_versions['os'])
+
+    for version in os_versions['versions']:
+      for field in version:
+        if field == 'channel':
+          channels.add(version['channel'])
+        else:
+          fields.add(field)
+
+  oses = sorted(oses)
+  channels = sorted(channels)
+  fields = sorted(fields)
+
+  # Command line parsing fun begins!
+  usage = ('%prog [options]\n'
+           'Print out information about a particular Chrome channel.')
+  parser = optparse.OptionParser(usage=usage)
+
+  parser.add_option('-o', '--os',
+                    choices=oses,
+                    default='win',
+                    help='The operating system of interest: %s '
+                         '[default: %%default]' % ', '.join(oses))
+  parser.add_option('-c', '--channel',
+                    choices=channels,
+                    default='stable',
+                    help='The channel of interest: %s '
+                         '[default: %%default]' % ', '.join(channels))
+  parser.add_option('-f', '--field',
+                    choices=fields,
+                    default='version',
+                    help='The field of interest: %s '
+                         '[default: %%default] ' % ', '.join(fields))
+  (opts, args) = parser.parse_args()
+
+  # Print out requested data if available.
+  for os_versions in data:
+    if os_versions['os'] != opts.os:
+      continue
+
+    for version in os_versions['versions']:
+      if version['channel'] != opts.channel:
+        continue
+
+      if opts.field not in version:
+        continue
+
+      print version[opts.field]
+      return 0
+
+  print 'Error: unable to find %s for Chrome %s %s.' % (
+      opts.field, opts.os, opts.channel)
+  return 1
+
+if __name__ == '__main__':
+  sys.exit(main())