Add apply_gerrit_ref to bot_update api

recipe_modules/tryserver/api.py

Index: recipe_modules/tryserver/api.py
diff --git a/recipe_modules/tryserver/api.py b/recipe_modules/tryserver/api.py
index f18c2b5d93227ffe0cf4c351de2dcf3b64dbfdb3..889ce8606de114f272691c88fe1a5d412af6152d 100644
--- a/recipe_modules/tryserver/api.py
+++ b/recipe_modules/tryserver/api.py
@@ -5,11 +5,21 @@
 import collections
 import contextlib
 import hashlib
+import os
+import sys
+import uuid
 
 from recipe_engine import recipe_api
 
+# Construct path to bot_update.
+sys.path.append(
+    os.path.abspath(
+        os.path.join(os.path.realpath(__file__), os.pardir, os.pardir,
+                     'bot_update', 'resources')))
+import bot_update

[rmistry, 2016/08/18 18:39:51]

Did not want to duplicate all the work already done in
https://cs.chromium.org/chromium/tools/depot_tools/recipe_modules/bot_update/...
Which is why I am instead calling it from here.

[tandrii(chromium), 2016/08/18 18:54:13]

that's bad. And it's against the spirit of recipes, and if it works, it's a bug.

[rmistry, 2016/08/18 20:27:50]

It does work (I tried it out locally).

Could I instead extract out apply_gerrit into it's own recipe_module and use it
from tryserver and bot_update ?
Actually not sure if that would work since bot_update here is a resource and not
a recipe_module. Any other suggestions?

[tandrii(chromium), 2016/08/18 20:30:09]

That OR wdyt about adding new API in bot_update + new resource file in
bot_update, say apply_gerrit.py which:

  # That's allowed, so long as you have __init__.py, 
  import bot_update
  if __name__ == '__main__':
    bot_update.whatever_you_need

 
 PATCH_STORAGE_RIETVELD = 'rietveld'
+PATCH_STORAGE_GERRIT = 'gerrit'
 PATCH_STORAGE_GIT = 'git'
 PATCH_STORAGE_SVN = 'svn'
 
@@ -136,11 +146,19 @@ class TryserverApi(recipe_api.RecipeApi):
         None, 'oauth2' (see also api.rietveld.apply_issue.)
     """
     storage = self.determine_patch_storage()
-
     if storage == PATCH_STORAGE_RIETVELD:
       return self.m.rietveld.apply_issue(
           self.m.rietveld.calculate_issue_root(),
           authentication=authentication)
+    elif storage == PATCH_STORAGE_GERRIT:
+      patch_project = (self.m.properties.get('patch_project') or
+                       self.m.properties.get('project'))
+      return bot_update.apply_gerrit_ref(
+          gerrit_repo=self.m.properties.get('repository') or 'origin',
+          gerrit_ref=self.m.properties.get('event.patchSet.ref'),
+          root=str(self.m.path['slave_build'].join(patch_project)),
+          gerrit_reset=True,
+          gerrit_rebase_patch_ref=True)
     elif storage == PATCH_STORAGE_SVN:
       return self.apply_from_svn(cwd)
     elif storage == PATCH_STORAGE_GIT: