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

git_cl.py

Index: git_cl.py
diff --git a/git_cl.py b/git_cl.py
index a1f58c8561f8129afd9cab9cf3de775fd5864d87..2a0b27492226a66168a44f7ec81ade81860fbb8c 100755
--- a/git_cl.py
+++ b/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 +533,29 @@ 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'),
+        'builder_name': json.loads(
+            build.get('parameters_json', '{}')).get('builder_name'),

[tandrii(chromium), 2016/08/30 22:22:45]

what about bucket_name? (that's where you can get what we call master name in
buildbot world).

also, i think it's worthwhile to report category here and url.

[qyearsley, 2016/08/30 23:41:24]

Added bucket and url.

By category, do you mean something like the category printed with `git cl
try-results`, which is generally a combination of "status", "result", and
"failure_reason"?

[tandrii(chromium), 2016/08/30 23:47:35]

no, i meant parameters_json.category. It's usually CQ or "git cl" or
"experimental". That said, doesn't have to be in this CL.

+        'failure_reason': build.get('failure_reason'),

[qyearsley, 2016/08/30 22:13:22]

Does it seem like a good idea to use build['key'] instead for "id" and "status"
and "parameters_json", and raise a KeyError and abort if the Buildbucket builds
list doesn't match what we expect?

I'm thinking here that whatever consumes this JSON should check for nulls, and
handle that, and if at some point we discover that builder_name or status is
null, then that indicates that maybe the buildbucket response isn't as expected
and something here should be updated.

[tandrii(chromium), 2016/08/30 22:22:45]

What's build['key']? I don't see it in buildbucket docs.
this -> sgtm.

[qyearsley, 2016/08/30 23:41:25]

Ah, that's not a real thing, what I meant was "does it seem like a good idea to
use the square bracket operator (__getitem__) which raises a KeyError, instead
of dict.get?". Sounds like dict.get is a reasonable way to do it?

[tandrii(chromium), 2016/08/30 23:47:35]

ah, dict.get() is the right way.

+    }
+
+  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 +4778,8 @@ 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 +4808,10 @@ 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