Auto find tryserver master for git cl try

git_cl.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 # Copyright (C) 2008 Evan Martin <martine@danga.com>
 
 """A git-command for integrating reviews on Rietveld."""
 
 from distutils.version import LooseVersion
@@ skipping 2190 matching lines @@
   """Fetches the tree status from a json url and returns the message
   with the reason for the tree to be opened or closed."""
   url = settings.GetTreeStatusUrl()
   json_url = urlparse.urljoin(url, '/current?format=json')
   connection = urllib2.urlopen(json_url)
   status = json.loads(connection.read())
   connection.close()
   return status['message']
 
 
+def GetBuilderMaster(bot_list):
+  """For a given builder, fetch the master from AE if available."""
+  map_url = 'https://builders-map.appspot.com/'
+  try:
+    master_map = json.load(urllib2.urlopen(map_url))
+  except urllib2.URLError as e:
+    return None, ('Failed to fetch builder-to-master map from %s. Error: %s.' %
+                  (map_url, e))
+  except ValueError as e:
+    return None, ('Invalid json string from %s. Error: %s.' % (map_url, e))
+  if not master_map:
+    return None, 'Failed to build master map.'
+
+  result_master = ''
+  for bot in bot_list:
+    builder = bot.split(':', 1)[0]
+    master_list = master_map.get(builder, [])
+    if not master_list:
+      return None, ('No matching master for builder %s.' % builder)
+    elif len(master_list) > 1:
+      return None, ('The builder name %s exists in multiple masters %s.' %
+                    (builder, master_list))
+    else:
+      cur_master = master_list[0]
+      if not result_master:
+        result_master = cur_master
+      elif result_master != cur_master:
+        return None, 'The builders do not belong to the same master.'
+  return result_master, None
+
+
 def CMDtree(parser, args):
   """Shows the status of the tree."""
   _, args = parser.parse_args(args)
   status = GetTreeStatus()
   if 'unset' == status:
     print 'You must configure your tree status URL by running "git cl config".'
     return 2
 
   print "The tree is %s" % status
   print
   print GetTreeStatusReason()
   if status != 'open':
     return 1
   return 0
 
 
 def CMDtry(parser, args):
   """Triggers a try job through Rietveld."""
   group = optparse.OptionGroup(parser, "Try job options")
   group.add_option(
       "-b", "--bot", action="append",
       help=("IMPORTANT: specify ONE builder per --bot flag. Use it multiple "
             "times to specify multiple builders. ex: "
-            "'-bwin_rel:ui_tests,webkit_unit_tests -bwin_layout'. See "
+            "'-b win_rel:ui_tests,webkit_unit_tests -b win_layout'. See "
             "the try server waterfall for the builders name and the tests "
             "available. Can also be used to specify gtest_filter, e.g. "
-            "-bwin_rel:base_unittests:ValuesTest.*Value"))
+            "-b win_rel:base_unittests:ValuesTest.*Value"))
   group.add_option(
       "-m", "--master", default='',
       help=("Specify a try master where to run the tries."))
   group.add_option(
       "-r", "--revision",
       help="Revision to use for the try job; default: the "
            "revision will be determined by the try server; see "
            "its waterfall for more info")
   group.add_option(
       "-c", "--clobber", action="store_true", default=False,
@@ skipping 21 matching lines @@
     parser.error('Need to upload first')
 
   props = cl.GetIssueProperties()
   if props.get('private'):
     parser.error('Cannot use trybots with private issue')
 
   if not options.name:
     options.name = cl.GetBranch()
 
   if options.bot and not options.master:
-    parser.error('For manually specified bots please also specify the '
-                 'tryserver master, e.g. "-m tryserver.chromium.linux".')
+    options.master, err_msg = GetBuilderMaster(options.bot)
+    if err_msg:
+      parser.error('Tryserver master cannot be found because: %s\n'
+                   'Please manually specify the tryserver master'
+                   ', e.g. "-m tryserver.chromium.linux".' % err_msg)
 
   def GetMasterMap():
     # Process --bot and --testfilter.
     if not options.bot:
       change = cl.GetChange(cl.GetCommonAncestorWithUpstream(), None)
 
       # Get try masters from PRESUBMIT.py files.
       masters = presubmit_support.DoGetTryMasters(
           change,
           change.LocalPaths(),
@@ skipping 342 matching lines @@
         ('AppEngine is misbehaving and returned HTTP %d, again. Keep faith '
           'and retry or visit go/isgaeup.\n%s') % (e.code, str(e)))
 
 
 if __name__ == '__main__':
   # These affect sys.stdout so do it outside of main() to simplify mocks in
   # unit testing.
   fix_encoding.fix_encoding()
   colorama.init()
   sys.exit(main(sys.argv[1:]))