Add a --json option to git cl try-results.

For use in scripts that check try job results, this is
currently practically the same as making requests to
https://codereview.chromium.org/api/<cl-number>/<patchset-number>.

However, I think that this might be more future-proof, since
it fetches try job information from Buildbucket, and I expect
to still work after migration from Rietveld to Gerrit.

BUG=640354

Review-Url: https://codereview.chromium.org/2274743003

git_cl.py

@@ -398,7 +398,7 @@ def trigger_try_jobs(auth_config, changelist, options, masters, category):
 def fetch_try_jobs(auth_config, changelist, options):
   """Fetches try jobs from buildbucket.
 
-  Returns a map from build id to build info as json dictionary.
+  Returns a map from build id to build info as a dictionary.
   """
   rietveld_url = settings.GetDefaultServerUrl()
   rietveld_host = urlparse.urlparse(rietveld_url).hostname
@@ -533,6 +533,31 @@ def print_try_jobs(options, builds):
   print('Total: %d try jobs' % total)
 
 
+def write_try_results_json(output_file, builds):
+  """Writes a subset of the data from fetch_try_jobs to a file as JSON.
+
+  The input |builds| dict is assumed to be generated by Buildbucket.
+  Buildbucket documentation: http://goo.gl/G0s101
+  """
+
+  def convert_build_dict(build):
+    return {
+        'buildbucket_id': build.get('id'),
+        'status': build.get('status'),
+        'result': build.get('result'),
+        'bucket': build.get('bucket'),
+        'builder_name': json.loads(
+            build.get('parameters_json', '{}')).get('builder_name'),
+        'failure_reason': build.get('failure_reason'),
+        'url': build.get('url'),
+    }
+
+  converted = []
+  for _, build in sorted(builds.items()):
+      converted.append(convert_build_dict(build))
+  write_json(output_file, converted)
+
+
 def MatchSvnGlob(url, base_url, glob_spec, allow_wildcards):
   """Return the corresponding git ref if |base_url| together with |glob_spec|
   matches the full |url|.
@@ -4755,6 +4780,8 @@ def CMDtry_results(parser, args):
   group.add_option(
       "--buildbucket-host", default='cr-buildbucket.appspot.com',
       help="Host of buildbucket. The default host is %default.")
+  group.add_option(
+      '--json', help='Path of JSON output file to write try job results to.')
   parser.add_option_group(group)
   auth.add_auth_options(parser)
   options, args = parser.parse_args(args)
@@ -4783,7 +4810,10 @@ def CMDtry_results(parser, args):
     print('ERROR: Exception when trying to fetch try jobs: %s\n%s' %
           (e, stacktrace))
     return 1
-  print_try_jobs(options, jobs)
+  if options.json:
+    write_try_results_json(options.json, jobs)
+  else:
+    print_try_jobs(options, jobs)
   return 0
 
 

tests/git_cl_test.py

@@ -1484,7 +1484,7 @@ class TestGitCl(TestCase):
     })
     self.calls.append(
         ((['ask_for_data', 'If you know what you are doing, '
-				   								 'press Enter to continue, Ctrl+C to abort.'],), ''))
+                           'press Enter to continue, Ctrl+C to abort.'],), ''))
     self.assertIsNone(cl.EnsureAuthenticated(force=False))
 
   def test_gerrit_ensure_authenticated_ok(self):
@@ -1850,6 +1850,54 @@ class TestGitCl(TestCase):
         out.getvalue(),
         'scheduled CQ Dry Run on https://codereview.chromium.org/123\n')
 
+  def test_write_try_results_json(self):
+    builds = {
+        '9000': {
+            'id': '9000',
+            'status': 'STARTED',
+            'url': 'http://build.cr.org/p/x.y/builders/my-builder/builds/2',
+            'result_details_json': '{"properties": {}}',
+            'bucket': 'master.x.y',
+            'created_by': 'user:someone@chromium.org',
+            'created_ts': '147200002222000',
+            'parameters_json': '{"builder_name": "my-builder", "category": ""}',
+        },
+        '8000': {
+            'id': '8000',
+            'status': 'COMPLETED',
+            'result': 'FAILURE',
+            'failure_reason': 'BUILD_FAILURE',
+            'url': 'http://build.cr.org/p/x.y/builders/my-builder/builds/1',
+            'result_details_json': '{"properties": {}}',
+            'bucket': 'master.x.y',
+            'created_by': 'user:someone@chromium.org',
+            'created_ts': '147200001111000',
+            'parameters_json': '{"builder_name": "my-builder", "category": ""}',
+        },
+    }
+    expected_output = [
+        {
+            'buildbucket_id': '8000',
+            'bucket': 'master.x.y',
+            'builder_name': 'my-builder',
+            'status': 'COMPLETED',
+            'result': 'FAILURE',
+            'failure_reason': 'BUILD_FAILURE',
+            'url': 'http://build.cr.org/p/x.y/builders/my-builder/builds/1',
+        },
+        {
+            'buildbucket_id': '9000',
+            'bucket': 'master.x.y',
+            'builder_name': 'my-builder',
+            'status': 'STARTED',
+            'result': None,
+            'failure_reason': None,
+            'url': 'http://build.cr.org/p/x.y/builders/my-builder/builds/2',
+        }
+    ]
+    self.calls = [(('write_json', 'output.json', expected_output), '')]
+    git_cl.write_try_results_json('output.json', builds)
+
   def _common_GerritCommitMsgHookCheck(self):
     self.mock(git_cl.sys, 'stdout', StringIO.StringIO())
     self.mock(git_cl.os.path, 'abspath',