metrics: Collect git version.

Bug: None
Change-Id: I73545ad59134c6e5dbeb47fb2e8168a5afc0e497
Reviewed-on: https://chromium-review.googlesource.com/c/1296861
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>

metrics.py

@@ -213,7 +213,14 @@ class MetricsCollector(object):
     self.add('python_version', metrics_utils.get_python_version())
     self.add('host_os', gclient_utils.GetMacWinOrLinux())
     self.add('host_arch', detect_host_arch.HostArch())
-    self.add('depot_tools_age', metrics_utils.get_repo_timestamp(DEPOT_TOOLS))
+
+    depot_tools_age = metrics_utils.get_repo_timestamp(DEPOT_TOOLS)
+    if depot_tools_age is not None:
+      self.add('depot_tools_age', depot_tools_age)
+
+    git_version = metrics_utils.get_git_version()
+    if git_version:
+      self.add('git_version', git_version)
 
     self._upload_metrics_data()
     if exception:

metrics_utils.py

@@ -138,12 +138,28 @@ KNOWN_HTTP_ARGS = {
   'LABELS',
 }
 
+GIT_VERSION_RE = re.compile(
+  r'git version (\d)\.(\d{0,2})\.(\d{0,2})'
+)
+
 
 def get_python_version():
   """Return the python version in the major.minor.micro format."""
   return '{v.major}.{v.minor}.{v.micro}'.format(v=sys.version_info)
 
 
+def get_git_version():
+  """Return the Git version in the major.minor.micro format."""
+  p = subprocess2.Popen(
+      ['git', '--version'],
+      stdout=subprocess2.PIPE, stderr=subprocess2.PIPE)
+  stdout, _ = p.communicate()
+  match = GIT_VERSION_RE.match(stdout)
+  if not match:
+    return None
+  return '%s.%s.%s' % match.groups()
+
+
 def return_code_from_exception(exception):
   """Returns the exit code that would result of raising the exception."""
   if exception is None:

tests/metrics_test.py

@@ -65,9 +65,12 @@ class MetricsCollectorTest(unittest.TestCase):
                lambda: 'x86').start()
     mock.patch('metrics_utils.get_repo_timestamp',
                lambda _: 1234).start()
+    mock.patch('metrics_utils.get_git_version',
+               lambda: '2.18.1').start()
 
     self.default_metrics = {
         "python_version": "2.7.13",
+        "git_version": "2.18.1",
         "execution_time": 1000,
         "timestamp": 0,
         "exit_code": 0,
@@ -697,6 +700,24 @@ class MetricsUtilsTest(unittest.TestCase):
     http_metrics = metrics_utils.extract_http_metrics('', '', 0, 12345.25)
     self.assertEqual(12345.25, http_metrics['response_time'])
 
+  @mock.patch('metrics_utils.subprocess2.Popen')
+  def test_get_git_version(self, mockPopen):
+    """Tests that we can get the git version."""
+    mockProcess = mock.Mock()
+    mockProcess.communicate.side_effect = [('git version 2.18.0.123.foo', '')]
+    mockPopen.side_effect = [mockProcess]
+
+    self.assertEqual('2.18.0', metrics_utils.get_git_version())
+
+  @mock.patch('metrics_utils.subprocess2.Popen')
+  def test_get_git_version_unrecognized(self, mockPopen):
+    """Tests that we can get the git version."""
+    mockProcess = mock.Mock()
+    mockProcess.communicate.side_effect = [('Blah blah blah', 'blah blah')]
+    mockPopen.side_effect = [mockProcess]
+
+    self.assertIsNone(metrics_utils.get_git_version())
+
 
 if __name__ == '__main__':
   unittest.main()