[tools/perf] Start creating flakiness_cli

This first version just adds an entry point for the script, and simple
api calls to test-results server to retrieve the json data.

Bug: 875251
Change-Id: I14de8275e1e9ffe28935d5e172add60011ec5b62
Reviewed-on: https://chromium-review.googlesource.com/1179837
Commit-Queue: Juan Antonio Navarro Pérez <perezju@chromium.org>
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Cr-Commit-Position: refs/heads/master@{#584784}

tools/perf/flakiness_cli

+#!/usr/bin/env python
+# Copyright 2018 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.
+
+"""This tool provides a command line interface for the flakiness dashboard."""
+
+import argparse
+import sys
+
+from test_results import api
+
+
+def main():
+  parser = argparse.ArgumentParser()
+  subparsers = parser.add_subparsers(dest='action')
+  subparsers.required = True
+  subparser = subparsers.add_parser('builders')
+  subparser = subparsers.add_parser('results')
+  subparser.add_argument('master')
+  subparser.add_argument('builder')
+  subparser.add_argument('test_type')
+  args = parser.parse_args()
+
+  if args.action == 'builders':
+    print api.GetBuilders()
+  elif args.action == 'results':
+    print api.GetTestResults(args.master, args.builder, args.test_type)
+  else:
+    raise NotImplementedError(args.action)
+
+
+if __name__ == '__main__':
+  sys.exit(main())

tools/perf/test_results/__init__.py

+# Copyright 2018 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.

tools/perf/test_results/api.py

+# Copyright 2018 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.
+
+import json
+import urllib
+import urllib2
+
+
+TEST_RESULTS_SERVER = 'http://test-results.appspot.com'
+TOOL_USER_AGENT = 'flakiness_cli/0.1'
+
+
+def _Request(path, params=None):
+  """Request json data from the test results server."""
+  url = TEST_RESULTS_SERVER + path
+  if params:
+    url += '?' + urllib.urlencode(params)
+  request = urllib2.Request(url, headers={'User-Agent': TOOL_USER_AGENT})
+  response = urllib2.urlopen(request)
+  return json.load(response)
+
+
+def GetBuilders():
+  """Retrieve json with list of all known masters, builders, and test_types."""
+  return _Request('/data/builders')
+
+
+def GetTestResults(master, builder, test_type):
+  """Retrieve test results json for a given master, builder, and test_type."""
+  return _Request('/testfile', {
+      'name': 'results.json',
+      'master': master,
+      'builder': builder,
+      'testtype': test_type})