puppet_compiler_submodule

diff --git a/puppet_compiler/prepare.py b/puppet_compiler/prepare.py
index 6a61b21..81f18a9 100644
--- a/puppet_compiler/prepare.py
+++ b/puppet_compiler/prepare.py
@@ -2,6 +2,7 @@ from contextlib import contextmanager
 import json
 import subprocess
 import os
+import re
 import shutil
 import requests
 from puppet_compiler import _log
@@ -116,7 +117,6 @@ class ManageCode(object):
 
     def _fetch_change(self):
         """get changes from the change directly"""
-        git = Git()
         headers = {'Accept': 'application/json',
                    'Content-Type': 'application/json; charset=UTF-8'}
         change = requests.get(
@@ -128,19 +128,57 @@ class ManageCode(object):
         json_data = change.text.split("\n")[-2:][0]
         res = json.loads(json_data)
         revision = res["revisions"].values()[0]["_number"]
+        project = res["project"]
         ref = 'refs/changes/%02d/%d/%d' % (
             self.change_id % 100,
             self.change_id,
             revision)
         _log.debug(
-            'Downloading patch for change %d, revision %d',
-            self.change_id, revision)
-        git.fetch('-q', 'https://gerrit.wikimedia.org/r/operations/puppet',
-                  ref)
-        git.checkout('FETCH_HEAD')
-        git.pull('--rebase', 'origin', 'production')
+            'Downloading patch for project %s, change %d, revision %d',
+            project, self.change_id, revision)
+
+        # Assumption:
+        # Gerrit suported repo names and branches:
+        # 1) operations/puppet - origin/production
+        # 2) operations/puppet/submodulename - origin/master
+        if project == 'operations/puppet':
+            self._pull_gerrit_revision(project, ref, 'production')
+        else:
+            self._update_submodule_repo(project, ref, 'master')
+
         # Update submodules according to the last hash of the parent repo.
-        git.submodule('update', '--init')
+        _log.debug('Running submodule init')
+        self.git.submodule('update', '--init')
+
+    def _update_submodule_repo(self, project, gerrit_rev, gerrit_origin_branch):
+        _log.debug('The change has not been filed for the main puppet repo.\
+            Checking submodule repository matching the regex operations/puppet/(\w*)')
+        submodule_name = self._get_submodule_name(project)
+        if submodule_name:
+            submodule_path = os.getcwd + '/modules/' + submodule_name
+            _log.debug('Submodule repository name: %s path: %s',
+                submodule_name, submodule_path)
+            if os.path.exists(submodule_path):
+                _log.debug('Executing git commands in %s', submodule_path)
+                with pushd(submodule_path):
+                    self._pull_gerrit_revision(project, gerrit_rev, gerrit_origin_branch)
+            else:
+                _log.debug('Cannot access the submodule directory: %s', submodule_path)
+                return
+        else:
+            _log.debug('No gerrit repository found!')
+            return
+
+    def _get_submodule_name(self, project):
+        submodule_matcher = re.search('operations/puppet/(\w*)$', project)
+        if submodule_matcher:
+            return submodule_matcher.group(1)
+        return None
+
+    def _pull_gerrit_revision(self, project, revision, origin_branch):
+        self.git.fetch('-q', 'https://gerrit.wikimedia.org/r/' + project, revision)
+        self.git.checkout('FETCH_HEAD')
+        self.git.pull('--rebase', 'origin', origin_branch)
 
     def _sh(command):
         try:
diff --git a/puppet_compiler/tests/test_prepare.py b/puppet_compiler/tests/test_prepare.py
index add277b..d87515e 100644
--- a/puppet_compiler/tests/test_prepare.py
+++ b/puppet_compiler/tests/test_prepare.py
@@ -90,3 +90,20 @@ class TestManageCode(unittest.TestCase):
         exim_priv = os.path.join(self.m.prod_dir, 'private/modules/privateexim')
         exim_pub = os.path.join(self.m.prod_dir, 'src/modules/privateexim')
         mock_symlink.assert_any_call(exim_priv, exim_pub)
+
+    def test_get_submodule_name(self):
+        assert None == self.m._get_submodule_name('not_a_valid_project')
+        assert None == self.m._get_submodule_name('/operations/puppet/not_a_valid_project/bla')
+        assert 'varnish' == self.m._get_submodule_name('/operations/puppet/varnish')
+
+
+
+
+
+
+
+
+
+
+
+