Enforce users to specify a 'pool' dimension when triggering a task.

appengine/swarming/server/task_request.py

 # coding: utf-8
 # Copyright 2014 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.
 
 """Tasks definition.
 
 Each user request creates a new TaskRequest. The TaskRequest instance saves the
 metadata of the request, e.g. who requested it, when why, etc. It links to the
 actual data of the request in a TaskProperties. The TaskProperties represents
@@ skipping 415 matching lines @@
     """Adds automatic tags."""
     super(TaskRequest, self)._pre_put_hook()
     self.properties._pre_put_hook()
     if self.properties.is_terminate:
       if not self.priority == 0:
         raise datastore_errors.BadValueError(
             'terminate request must be priority 0')
     elif self.priority == 0:
       raise datastore_errors.BadValueError(
           'priority 0 can only be used for terminate request')
-    self.tags.append('priority:%s' % self.priority)
-    self.tags.append('user:%s' % self.user)
-    for key, value in self.properties.dimensions.iteritems():
-      self.tags.append('%s:%s' % (key, value))
-    self.tags = sorted(set(self.tags))
+
+    if not self.properties.dimensions:
+      raise datastore_errors.BadValueError('dimensions must be specified')
+    dim_keys = self.properties.dimensions.keys()
+    if 'pool' not in dim_keys and 'id' not in dim_keys:
+      raise datastore_errors.BadValueError(
+          'At least one of \'id\' or \'pool\' must be used as dimensions')
+
     if (self.pubsub_topic and
         not pubsub.validate_full_name(self.pubsub_topic, 'topics')):
       raise datastore_errors.BadValueError(
           'bad pubsub topic name - %s' % self.pubsub_topic)
     if self.pubsub_auth_token and not self.pubsub_topic:
       raise datastore_errors.BadValueError(
           'pubsub_auth_token requires pubsub_topic')
     if self.pubsub_userdata and not self.pubsub_topic:
       raise datastore_errors.BadValueError(
           'pubsub_userdata requires pubsub_topic')
 
+    self.tags.append('priority:%s' % self.priority)
+    self.tags.append('user:%s' % self.user)
+    for key, value in self.properties.dimensions.iteritems():
+      self.tags.append('%s:%s' % (key, value))
+    self.tags = sorted(set(self.tags))
+
 
 def _new_request_key():
   """Returns a valid ndb.Key for this entity.
 
   Task id is a 64 bits integer represented as a string to the user:
   - 1 highest order bits set to 0 to keep value positive.
   - 43 bits is time since _BEGINING_OF_THE_WORLD at 1ms resolution.
     It is good for 2**43 / 365.3 / 24 / 60 / 60 / 1000 = 278 years or 2010+278 =
     2288. The author will be dead at that time.
   - 16 bits set to a random value or a server instance specific value. Assuming
@@ skipping 192 matching lines @@
   _put_request(request)
   return request
 
 
 def validate_priority(priority):
   """Throws ValueError if priority is not a valid value."""
   if 0 > priority or MAXIMUM_PRIORITY < priority:
     raise datastore_errors.BadValueError(
         'priority (%d) must be between 0 and %d (inclusive)' %
         (priority, MAXIMUM_PRIORITY))