Enforce limits on configs

appengine/gce-backend/config.py

 # Copyright 2016 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.
 
 """Utilities for reading GCE Backend configuration."""
 
 import collections
 import logging
 
 from components import utils
@@ skipping 113 matching lines @@
   # We don't do any GCE-specific validation here. Just require globally
   # unique base name because base name is used as the key in the datastore.
   base_names = set()
   valid = True
   for template in config.templates:
     if template.base_name in base_names:
       context.error('base_name %s is not globally unique.', template.base_name)
       valid = False
     else:
       base_names.add(template.base_name)
+  if len(base_names) > 10:
+    context.error('Too many instance templates.')
+    valid = False
   metrics.config_valid.set(valid, fields={'config': TEMPLATES_CFG_FILENAME})
 
 
 @validation.self_rule(
     MANAGERS_CFG_FILENAME, config_pb2.InstanceGroupManagerConfig)
 def validate_manager_config(config, context):
   """Validates an InstanceGroupManagerConfig instance."""
   # We don't do any GCE-specific validation here. Just require per-template
   # unique zone because template+zone is used as a key in the datastore.
   zones = collections.defaultdict(set)
   valid = True
   for manager in config.managers:
     if manager.zone in zones[manager.template_base_name]:
       context.error(
           'zone %s is not unique in template %s.',
           manager.zone,
           manager.template_base_name,
       )
       valid = False
     else:
       zones[manager.template_base_name].add(manager.zone)
+    if manager.minimum_size > manager.maximum_size:
+      context.error(
+          'minimum_size > maximum_size for zone %s in template %s.',
+          manager.zone,
+          manager.template_base_name,
+      )
+      valid = False
+    if manager.maximum_size > 1000:
+      # A GCE InstanceGroup is limited to 1000 instances.
+      context.error(
+          'maximum_size > 1000 for zone %s in template %s.',
+          manager.zone,
+          manager.template_base_name,
+      )
+      valid = False
   metrics.config_valid.set(valid, fields={'config': MANAGERS_CFG_FILENAME})
 
 
 @validation.self_rule(SETTINGS_CFG_FILENAME, config_pb2.SettingsCfg)
 def validate_settings_config(config, context):
   if config.HasField('mp_server'):
     if not validation.is_valid_secure_url(config.mp_server):
       context.error(
           'mp_server must start with "https://" or "http://localhost"')
 
@@ skipping 11 matching lines @@
     if cfg.mp_server != current_config.instance_url:
       logging.info('Updating Machine Provider server to %s', cfg.mp_server)
       current_config.modify(instance_url=cfg.mp_server)
   return rev, cfg
 
 
 @utils.cache_with_expiration(60)
 def settings():
   """Loads settings from an NDB-based cache or a default one if not present."""
   return _get_settings()[1]