Findit] Flake Checker: Pipeline to trigger try jobs to identify flake culprits

appengine/findit/waterfall/flake/process_flake_try_job_result_pipeline.py

Index: appengine/findit/waterfall/flake/process_flake_try_job_result_pipeline.py
diff --git a/appengine/findit/waterfall/flake/process_flake_try_job_result_pipeline.py b/appengine/findit/waterfall/flake/process_flake_try_job_result_pipeline.py
new file mode 100644
index 0000000000000000000000000000000000000000..9ff523bb226cf2b2385a3ff871bcd78b637c6d14
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+++ b/appengine/findit/waterfall/flake/process_flake_try_job_result_pipeline.py
@@ -0,0 +1,74 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+from google.appengine.ext import ndb
+
+from common.pipeline_wrapper import BasePipeline
+from model.flake.master_flake_analysis import DataPoint
+
+
+class ProcessFlakeTryJobResultPipeline(BasePipeline):
+  """A pipeline for processing a flake try job result."""
+
+  # Arguments number differs from overridden method - pylint: disable=W0221
+  def run(self, revision, commit_position, try_job_result, urlsafe_try_job_key,
+          urlsafe_flake_analysis_key):
+    """Extracts pass rate information and updates flake analysis.
+
+    Args:
+      revision (str): The git hash the try job was run against.
+      commit_position (int): The commit position corresponding to |revision|.
+      try_job_result (dict): The result dict reported by buildbucket.
+          Example:
+          {
+            'report': {
+                'metadata': {},
+                'result': {
+                    'cafed52c5f3313646b8e04e05601b5cb98f305b3': {
+                        'browser_tests': {
+                            'status': 'failed',
+                            'failures': ['TabCaptureApiTest.FullscreenEvents'],
+                            'valid': True,
+                            'pass_fail_counts': {
+                                'TabCaptureApiTest.FullscreenEvents': {
+                                    'pass_count': 28,
+                                    'fail_count': 72
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+      urlsafe_try_job_key (str): The urlsafe key to the corresponding try job
+          entity.
+      urlsafe_flake_analysis_key (str): The urlsafe key for the master flake
+          analysis entity to be updated.
+    """
+    flake_analysis = ndb.Key(urlsafe=urlsafe_flake_analysis_key).get()
+    try_job = ndb.Key(urlsafe=urlsafe_try_job_key).get()
+    assert flake_analysis
+    assert try_job
+
+    step_name = flake_analysis.step_name
+    test_name = flake_analysis.test_name
+    result = try_job_result['report']['result']
+    pass_fail_counts = result[revision][step_name].get('pass_fail_counts', {})
+
+    if pass_fail_counts:
+      test_results = pass_fail_counts[test_name]
+      pass_count = test_results['pass_count']
+      fail_count = test_results['fail_count']
+      tries = pass_count + fail_count
+      pass_rate = float(pass_count) / tries
+    else:  # Test does not exist.
+      pass_rate = -1
+
+    data_point = DataPoint()
+    data_point.commit_position = commit_position
+    data_point.git_hash = revision
+    data_point.pass_rate = pass_rate
+    data_point.try_job_url = try_job.flake_results[-1].get('url')
+    # TODO(chanli): Add swarming task data.
+    flake_analysis.data_points.append(data_point)
+    flake_analysis.put()