Auto find tryserver master for git cl try

git_cl.py

Index: git_cl.py
diff --git a/git_cl.py b/git_cl.py
index 77f4a9e9f13c769e02e6acdadb087acb64f05224..23f8835fac1a7aecec9b664bd825afda2e72a657 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -2207,6 +2207,44 @@ def GetTreeStatusReason():
   connection.close()
   return status['message']
 

[M-A Ruel, 2014/08/14 18:42:02]

2 lines

[sheyang, 2014/08/14 19:50:22]

Done.

+def GetBuilderMaster(bot_list):
+  """For a given builder, fetch the master from AE if available."""
+  err_msg = ''
+  master_map = None
+  result_master = ''
+  map_url = 'https://builders-map.appspot.com/'
+  try:
+    res = urllib2.urlopen(map_url)
+    master_map = json.load(res)

[M-A Ruel, 2014/08/14 18:42:02]

master_map = json.load(urllib2.urlopen(map_url))

[sheyang, 2014/08/14 19:50:24]

Done.

+  except urllib2.URLError as url_e:

[M-A Ruel, 2014/08/14 18:42:02]

s/url_e/e/

[sheyang, 2014/08/14 19:50:22]

Done.

+    err_msg = ('Failed to fetch builder-to-master map from %s. Error: %s.' %

[M-A Ruel, 2014/08/14 18:42:02]

Why not return right away?

[sheyang, 2014/08/14 19:50:22]

Done.

+               (map_url, url_e))
+  except ValueError as val_e:

[M-A Ruel, 2014/08/14 18:42:02]

s/val_e/e/

[sheyang, 2014/08/14 19:50:22]

Done.

[sheyang, 2014/08/14 19:50:24]

Done.

+    err_msg = 'Invalid json string from %s. Error: %s.' % (map_url, val_e)
+
+  if master_map:

[M-A Ruel, 2014/08/14 18:42:02]

if not master_map:
  return None, err_msg

[sheyang, 2014/08/14 19:50:24]

Done.

+    for bot in bot_list:
+      if ':' in bot:
+        builder, _ = bot.split(':', 1)

[M-A Ruel, 2014/08/14 18:42:02]

builder = bot.split(':', 1)[0]

Remove line 2227, 2229-2230.

[sheyang, 2014/08/14 19:50:22]

Removed.

+      else:
+        builder = bot
+      master_list = master_map.get(builder, [])
+      if not master_list:
+        err_msg = 'Cannot find a master for builder %s.' % builder

[M-A Ruel, 2014/08/14 18:42:02]

It'd likely be simpler to return right away.

[sheyang, 2014/08/14 19:50:22]

Done.

+        break
+      elif len(master_list) > 1:
+        err_msg = ('The builder name %s exists in multiple masters %s.' %

[M-A Ruel, 2014/08/14 18:42:02]

Same

[sheyang, 2014/08/14 19:50:22]

Done.

+                   (builder, master_list))
+        break
+      else:
+        cur_master = master_list[0]
+        if not result_master:
+          result_master = cur_master
+        elif result_master != cur_master:
+          err_msg = 'The builders do not belong to the same master.'
+          result_master = ''

[M-A Ruel, 2014/08/14 18:42:02]

Return

[sheyang, 2014/08/14 19:50:24]

Done.

+          break
+  return result_master, err_msg
 

[M-A Ruel, 2014/08/14 18:42:02]

2 lines

[sheyang, 2014/08/14 19:50:24]

Done.

 def CMDtree(parser, args):
   """Shows the status of the tree."""
@@ -2231,10 +2269,10 @@ def CMDtry(parser, args):
       "-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."))
@@ -2276,8 +2314,11 @@ def CMDtry(parser, args):
     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.