mastermon: report step metrics

infra/services/mastermon/pollers.py

Index: infra/services/mastermon/pollers.py
diff --git a/infra/services/mastermon/pollers.py b/infra/services/mastermon/pollers.py
index 369fb4114db42ef600a7b0f96c2aa0a6935a00f5..61f97d6a00875e30890b91665670c82d994f586e 100644
--- a/infra/services/mastermon/pollers.py
+++ b/infra/services/mastermon/pollers.py
@@ -141,6 +141,11 @@ class FilePoller(Poller):
   total_times = ts_mon.CumulativeDistributionMetric(
       'buildbot/master/builders/builds/total_durations', bucketer=bucketer)
 
+  step_result_count = ts_mon.CounterMetric(
+      'buildbot/master/builders/steps/results/count')
+  step_times = ts_mon.CumulativeDistributionMetric(
+      'buildbot/master/builders/steps/durations', bucketer=bucketer)
+
   def poll(self):
     LOGGER.info('Collecting results from %s', self._url)
 
@@ -173,3 +178,14 @@ class FilePoller(Poller):
       self.pending_times.add(data['pending_s'], fields)
     if 'total_s' in data:
       self.total_times.add(data['total_s'], fields)
+
+    if 'steps' in data:
+      for step in data['steps']:
+        step_fields = copy.copy(fields)
+        step_fields.update({
+          'step_name': step['step_name'],
+          'result': step['result'],
+        })
+
+        self.step_result_count.increment(step_fields)
+        self.step_times.add(step['duration_s'], step_fields)