Monitoring proxy for time series data

appengine/chrome_infra_mon_proxy/main.py

Index: appengine/chrome_infra_mon_proxy/main.py
diff --git a/appengine/chrome_infra_mon_proxy/main.py b/appengine/chrome_infra_mon_proxy/main.py
new file mode 100644
index 0000000000000000000000000000000000000000..80ba6ea7f7afee8c2e6ff84723c99cb2e54489f9
--- /dev/null
+++ b/appengine/chrome_infra_mon_proxy/main.py
@@ -0,0 +1,101 @@
+# 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.
+
+import logging
+import random
+import os
+import sys
+import time
+import urllib2
+import webapp2
+
+from protorpc import messages
+from protorpc import message_types
+from protorpc import remote
+
+from google.appengine.api import app_identity, taskqueue
+
+import admin_handler
+import common
+from components import auth
+
+VM_MODULES = ['vm1', 'vm2', 'vm3']
+
+
+def require_group_membership(group_name):
+  """Skip authorization for dev appserver."""

[agable, 2015/04/23 19:29:37]

nit: Odd docstring. First say what it *does*, then say the exceptions in which
it doesn't do that.

[Sergey Berezin (google), 2015/04/24 19:09:52]

Done.

+  if common.is_development_server():
+    auth_decorator = auth.public
+  else:
+    auth_decorator = auth.require( # pragma: no branch
+        lambda: auth.is_group_member(group_name))
+
+  def decorator(fn):
+    return auth_decorator(fn)
+  return decorator
+
+
+class NoBackendException(Exception):
+  pass
+
+
+class LoadBalancer(object):
+  """Balance the load among VM modules.
+
+  TODO(sergeyberezin): take into account health checks on the
+  corresponding NAT boxes. Specifically, fetch the health status
+  from the datastore in __init__(), and update it periodically as needed.
+  """
+  def __init__(self):
+    pass
+
+  def choose_module(self):
+    """Select a module to send the data to."""
+    # TODO(sergeyberezin) Implement load percentages for modules, for
+    # draining / canary / live rolling updates.
+    # TODO(sergeyberezin): perform health checks for the corresponding
+    # NAT boxes and drain modules appropriately.
+    return random.choice(VM_MODULES)
+
+
+def forward_data(data):
+  """Forwards the raw data to the backend."""
+  # Task queue should work correctly both in dev and prod server.
+  lb = LoadBalancer()
+  module_name = lb.choose_module()
+  logging.info('Forwarding request to module: %s', module_name)
+  hostname = app_identity.get_default_version_hostname()
+  if common.is_development_server():
+    protocol = 'http'
+  else:
+    protocol = 'https'
+  url = '%s://%s/%s' % (protocol, hostname, module_name)
+  request = urllib2.Request(url, data)
+  urllib2.urlopen(request)
+
+
+class MonacqHandler(auth.AuthenticatingHandler):
+  # Disable XSRF in local dev appserver; otherwise requests will fail.
+  if common.is_development_server():
+    xsrf_token_enforce_on = []  # pragma: no cover
+
+  @require_group_membership('service-account-monitoring-proxy')
+  def post(self):
+    forward_data(self.request.body)
+
+
+class MainHandler(common.BaseHandler):
+  def get(self):
+    self.render_response('main.html', title='Chrome Infra Monitoring Proxy')
+
+
+logging.basicConfig(level=logging.DEBUG)
+
+main_handlers = [
+    (r'/', MainHandler),
+    (r'/monacq', MonacqHandler),
+    (r'/admin/(.*)', admin_handler.AdminDispatch),
+]
+
+app = webapp2.WSGIApplication(main_handlers, debug=True)