make version of ts_mon compatible with appengine

appengine_module/gae_ts_mon/monitors.py

Index: appengine_module/gae_ts_mon/monitors.py
diff --git a/appengine_module/gae_ts_mon/monitors.py b/appengine_module/gae_ts_mon/monitors.py
new file mode 100644
index 0000000000000000000000000000000000000000..06b5a5f2021c8d60ecb89725c58e44289d4bb0c4
--- /dev/null
+++ b/appengine_module/gae_ts_mon/monitors.py
@@ -0,0 +1,98 @@
+# Copyright 2015 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.
+
+"""Classes representing the monitoring interface for tasks or devices.
+
+In appengine, a PubSubMonitor will be automatically initialized when initialize()
+is called, and there is no need to initialize it directly from this class.
+"""
+
+
+import base64
+import json
+import os
+
+from monacq.proto import metrics_pb2
+
+from third_party import httplib2
+from third_party.apiclient import discovery
+from third_party.oauth2client.client import GoogleCredentials
+
+
+class Monitor(object):
+  """Abstract base class encapsulating the ability to collect and send metrics.
+
+  This is a singleton class. There should only be one instance of a Monitor at
+  a time. It will be created and initialized by process_argparse_options. It
+  must exist in order for any metrics to be sent, although both Targets and
+  Metrics may be initialized before the underlying Monitor. If it does not exist
+  at the time that a Metric is sent, an exception will be raised.
+  """
+  @staticmethod
+  def _wrap_proto(data):
+    """Normalize MetricsData, list(MetricsData), and MetricsCollection.
+
+    Args:
+      input: A MetricsData, list of MetricsData, or a MetricsCollection.
+
+    Returns:
+      A MetricsCollection with the appropriate data attribute set.
+    """
+    if isinstance(data, metrics_pb2.MetricsCollection):
+      ret = data
+    elif isinstance(data, list):
+      ret = metrics_pb2.MetricsCollection(data=data)
+    else:
+      ret = metrics_pb2.MetricsCollection(data=[data])
+    return ret
+
+  def send(self, metric_pb):
+    raise NotImplementedError()
+
+
+class PubSubMonitor(Monitor):
+  """Class which publishes metrics to a Cloud Pub/Sub topic."""
+
+  _SCOPES = [
+      'https://www.googleapis.com/auth/pubsub',
+  ]
+
+  def _initialize(self, project, topic):
+    creds = GoogleCredentials.get_application_default()
+    creds = creds.create_scoped(self._SCOPES)
+    self._http = httplib2.Http()
+    creds.authorize(self._http)
+    self._api = discovery.build('pubsub', 'v1', http=self._http)
+    self._topic = 'projects/%s/topics/%s' % (project, topic)
+
+  def __init__(self, project, topic):
+    """Process monitoring related command line flags and initialize api.
+
+    Args:
+      project (str): the name of the Pub/Sub project to publish to.
+      topic (str): the name of the Pub/Sub topic to publish to.
+    """
+    self._initialize(project, topic)
+
+  def send(self, metric_pb):
+    """Send a metric proto to the monitoring api.
+
+    Args:
+      metric_pb (MetricsData or MetricsCollection): the metric protobuf to send
+    """
+    proto = self._wrap_proto(metric_pb)
+    body = {
+        'messages': [
+          {'data': base64.b64encode(proto.SerializeToString())},
+        ],
+    }
+    self._api.projects().topics().publish(
+        topic=self._topic,
+        body=body).execute(num_retries=5)
+
+
+class NullMonitor(Monitor):
+  """Class that doesn't send metrics anywhere."""
+  def send(self, metric_pb):
+    pass