Add build mailer capability to support gatekeeper_ng.

mailer.py

Index: mailer.py
diff --git a/mailer.py b/mailer.py
new file mode 100644
index 0000000000000000000000000000000000000000..ef15f868b73119c1015a835315b3fd0993915430
--- /dev/null
+++ b/mailer.py
@@ -0,0 +1,149 @@
+import datetime
+from google.appengine.api import mail
+import hashlib
+import hmac
+import logging
+import json
+import webapp2
+from webapp2_extras import jinja2
+
+import gatekeeper_mailer
+
+
+class BaseHandler(webapp2.RequestHandler):
+  """Provide a cached Jinja environment to each request."""
+  @webapp2.cached_property
+  def jinja2(self):
+    # Returns a Jinja2 renderer cached in the app registry.
+    return jinja2.get_jinja2(app=self.app)
+
+  def render_response(self, _template, **context):
+    # Renders a template and writes the result to the response.
+    rv = self.jinja2.render_template(_template, **context)
+    self.response.write(rv)
+
+
+class MainPage(BaseHandler):
+  def get(self):
+    context = {'title': 'Chromium Gatekeeper Mailer'}
+    self.render_response('main_mailer.html', **context)
+
+
+class Email(BaseHandler):
+  @staticmethod
+  def _validate_message(message, secret):
+    # Make this backwards compatable with python 2.6, since total_seconds()
+    # exists only in python 2.7.
+    utc_now_td = (datetime.datetime.utcnow() -
+        datetime.datetime.utcfromtimestamp(0))
+    utc_now = utc_now_td.days * 86400 + utc_now_td.seconds
+
+    if (utc_now < message['time']) or (utc_now - message['time'] > 60):
+      logging.error('message was rejected due to time')
+      return False
+
+    hasher = hmac.new(secret, '%s:%d:%d' % (message['message'],
+                                            message['time'],
+                                            message['salt']),
+                      hashlib.sha256)
+
+    client_hash = hasher.hexdigest()
+
+    return client_hash == message['sha256']
+
+
+  @staticmethod
+  def _verify_json(build_data):
+    fields = ['waterfall_url',
+              'build_url',
+              'project_name',
+              'builderName',
+              'steps',
+              'unsatisfied',
+              'revisions',
+              'blamelist',
+              'result',
+              'number',
+              'changes',
+              'reason',
+              'recipients']
+
+    for field in fields:
+      if field not in build_data:
+        logging.error('build_data did not contain field %s' % field)
+        return False
+
+    stepfields = ['started',
+                  'text',
+                  'results',
+                  'name',
+                  'logs',
+                  'urls']
+
+    if not build_data['steps']:
+      logging.error('build_data did not contain any steps')
+      return False
+    for step in build_data['steps']:
+      for field in stepfields:
+        if field not in step:
+          logging.error('build_step did not contain field %s' % field)
+          return False
+
+    return True
+
+  def post(self):
+    blob = self.request.get('json')
+    if not blob:
+      self.response.out.write('no json data sent')
+      logging.error('error no json sent')
+      self.error(400)
+      return
+
+    message = {}
+    try:
+      message = json.loads(blob)
+    except ValueError as e:
+      self.response.out.write('couldn\'t decode json')
+      logging.error('error decoding incoming json: %s' % e)
+      self.error(400)
+      return
+
+    if not self._validate_message(message, 'pajamas'):

[agable, 2013/08/01 17:52:44]

Nice secret :)

+      self.response.out.write('unauthorized')
+      logging.error('incoming message did not validate')
+      self.error(403)
+      return
+
+    build_data = json.loads(message['message'])
+
+    if not self._verify_json(build_data):
+      logging.error('error verifying incoming json: %s' % build_data)
+      self.response.out.write('json build format is incorrect')

[agable, 2013/08/01 17:52:44]

Could be a more informative error message -- what about it is incorrect? Not
necessary though.

+      self.error(400)
+      return
+
+    from_addr = build_data.get('from_addr', 'buildbot@chromium.org')

[agable, 2013/08/01 17:52:44]

Does sending as this address work, or does appengine get unhappy because you're
sending from a different domain than the app itself?

[Mike Stip (use stip instead), 2013/08/29 19:56:46]

it doesn't, fixed

+    recipients = ', '.join(build_data['recipients'])
+
+    template = gatekeeper_mailer.MailTemplate(build_data['waterfall_url'],
+                                              build_data['build_url'],
+                                              build_data['project_name'],
+                                              from_addr)
+
+
+    text_content, html_content, subject = template.genMessageContent(build_data)
+
+    message = mail.EmailMessage(sender=from_addr,
+                                subject=subject,
+                                #to=recipients,
+                                to=['xusydoc@chromium.org'],
+                                body=text_content,
+                                html=html_content)
+    logging.info('sending email to %s', recipients)
+    message.send()
+    self.response.out.write('email sent')
+
+
+app = webapp2.WSGIApplication([('/mailer', MainPage),
+                               ('/mailer/email', Email)],
+                              debug=True)