Create Tasks.Tags endpoint and Cron job

appengine/swarming/handlers_endpoints.py

 # Copyright 2015 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.
 
 """This module defines Swarming Server endpoints handlers."""
 
 import datetime
 import logging
 
 from google.appengine.api import datastore_errors
@@ skipping 405 matching lines @@
   def _query_from_request(self, request, sort=None):
     """Returns a TaskResultSummary query."""
     start = message_conversion.epoch_to_datetime(request.start)
     end = message_conversion.epoch_to_datetime(request.end)
     return task_result.get_result_summaries_query(
         start, end,
         sort or request.sort.name.lower(),
         request.state.name.lower(),
         request.tags)
 
+  @gae_ts_mon.instrument_endpoint()
+  @auth.endpoints_method(
+      message_types.VoidMessage, swarming_rpcs.TasksTags,
+      http_method='GET')
+  @auth.require(acl.is_privileged_user)
+  def tags(self, _request):
+    """Returns the cached set of tags currently seen in the fleet."""
+    tags = task_result.TagAggregation.KEY.get()
+    ft = [
+      swarming_rpcs.StringListPair(key=t.tag, value=t.values)
+      for t in tags.tags
+    ]
+    return swarming_rpcs.TasksTags(tasks_tags=ft, ts=tags.ts)
+
 
 BotId = endpoints.ResourceContainer(
     message_types.VoidMessage,
     bot_id=messages.StringField(1, required=True))
 
 
 BotEventsRequest = endpoints.ResourceContainer(
     swarming_rpcs.BotEventsRequest,
     bot_id=messages.StringField(1, required=True))
 
@@ skipping 248 matching lines @@
 def get_routes():
   return (
     endpoints_webapp2.api_routes(SwarmingServerService) +
     endpoints_webapp2.api_routes(SwarmingTaskService) +
     endpoints_webapp2.api_routes(SwarmingTasksService) +
     endpoints_webapp2.api_routes(SwarmingBotService) +
     endpoints_webapp2.api_routes(SwarmingBotsService) +
     # components.config endpoints for validation and configuring of luci-config
     # service URL.
     endpoints_webapp2.api_routes(config.ConfigApi))