swarming: switch to a 'capability focused' ACL system

appengine/swarming/server/task_request.py

 # coding: utf-8
 # Copyright 2014 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # 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 695 matching lines @@
   def task_id(self):
     """Returns the TaskResultSummary packed id, not the task request key."""
     return task_pack.pack_result_summary_key(
         task_pack.request_key_to_result_summary_key(self.key))
 
   @property
   def expiration_secs(self):
     """Reconstructs this value from expiration_ts and created_ts. Integer."""
     return int((self.expiration_ts - self.created_ts).total_seconds())
 
-  @property
-  def has_access(self):
-    """Returns True if the current user has read-write access to this request.
-
-    This is used for:
-      * Read access: ability to read the task info and logs.
-      * Write access: ability to cancel the task.
-
-    Warning: This function looks at the current Authentication context.
-    """
-    return (
-        acl.is_privileged_user() or
-        self.authenticated == auth.get_current_identity())
-
   def to_dict(self):
     """Converts properties_hash to hex so it is json serializable."""
     # to_dict() doesn't recurse correctly into ndb.LocalStructuredProperty!
     out = super(TaskRequest, self).to_dict(
         exclude=['pubsub_auth_token', 'properties', 'service_account_token'])
     out['properties'] = self.properties.to_dict()
     properties_hash = out['properties_hash']
     out['properties_hash'] = (
         properties_hash.encode('hex') if properties_hash else None)
     return out
@@ skipping 274 matching lines @@
   init_new_request(request, allow_high_priority, original_secret_bytes)
   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))