isolateserver: add checkbox to enable ts_mon

appengine/isolate/handlers_frontend.py

 # Copyright 2012 The Swarming Authors. All rights reserved.
 # Use of this source code is governed by the Apache v2.0 license that can be
 # found in the LICENSE file.
 
 """This module defines Isolate Server frontend url handlers."""
 
 import datetime
 import json
 
 import webapp2
@@ skipping 45 matching lines @@
 
 ### Restricted handlers
 
 
 class RestrictedConfigHandler(auth.AuthenticatingHandler):
   @auth.autologin
   @auth.require(auth.is_admin)
   def get(self):
     self.common(None)
 
+  @staticmethod
+  def cast_to_type(param_name, value):
+    def to_bool(value):
+      if type(value) is bool:
+        return value
+      return {'True': True, 'False': False}.get(value, False)
+
+    cast = {
+        'enable_ts_monitoring': to_bool,
+    }.get(param_name, str)
+    return cast(value)
+
   @auth.require(auth.is_admin)
   def post(self):
     # Convert MultiDict into a dict.
     params = {
-      k: self.request.params.getone(k) for k in self.request.params
+      k: self.cast_to_type(k, self.request.params.getone(k))
+      for k in self.request.params
       if k not in ('keyid', 'xsrf_token')
     }
     cfg = config.settings(fresh=True)
     keyid = int(self.request.get('keyid', '0'))
     if cfg.key.integer_id() != keyid:
       self.common('Update conflict %s != %s' % (cfg.key.integer_id(), keyid))
       return
     params['default_expiration'] = int(params['default_expiration'])
     cfg.populate(**params)
     try:
@@ skipping 219 matching lines @@
 def create_application(debug):
   """Creates the url router.
 
   The basic layouts is as follow:
   - /restricted/.* requires being an instance administrator.
   - /stats/.* has statistics.
   """
   acl.bootstrap()
   template.bootstrap()
   return webapp2.WSGIApplication(get_routes(), debug=debug)