swarming: send task tags to event_mon

appengine/swarming/event_mon_metrics.py

Index: appengine/swarming/event_mon_metrics.py
diff --git a/appengine/swarming/event_mon_metrics.py b/appengine/swarming/event_mon_metrics.py
index a0d1437f8cee09b650f582a9b3f51b99a74c0b8d..d194b9b8efef7ce0e3ffde72260603c86b501017 100644
--- a/appengine/swarming/event_mon_metrics.py
+++ b/appengine/swarming/event_mon_metrics.py
@@ -25,6 +25,20 @@ DIMENSIONS = (
 )
 
 
+TAGS = (
+    'build_id',

[M-A Ruel, 2016/12/15 20:51:34]

buildnumber ?

+    'buildername',
+    'codereview',

[M-A Ruel, 2016/12/15 20:51:34]

For Rietveld triggered task, it's 'rietveld'

+    'master',
+    'name',
+    'patch_project',
+    'project',
+    'purpose',
+    'slavename',
+    'stepname',
+)
+
+
 def _to_timestamp(dt):
   return int(time.mktime(dt.timetuple()))
 
@@ -140,6 +154,15 @@ def _task_summary_to_proto(summary, event):
     event.proto.swarming_task_event.deduped_from = summary.deduped_from
   event.proto.swarming_task_event.try_number = summary.try_number
 
+  for tag in summary.tags:
+    if ':' not in tag:
+      logging.error('Unexpected tag: %r', tag)
+      continue
+    name, value = tag.split(':', 1)
+    if name not in TAGS:
+      continue
+    getattr(event.proto.swarming_task_event.tags, name).append(value)
+
 
 def initialize():
   gae_event_mon.initialize('swarming')