Have service_manager start a cloudtail attached to each service it starts.

infra/services/service_manager/config_watcher.py

 # Copyright (c) 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import collections
 import glob
 import json
 import logging
 import os.path
 import time
@@ skipping 15 matching lines @@
   """Polls a directory for .json files describing services to be run.
 
   Tries to keep the running services in sync with the config files - services
   are started immediately when valid configs are added, restarted when their
   configs change (adding or removing args for example), and stopped when the
   configs are deleted.
   """
 
   def __init__(self, config_directory, config_poll_interval,
                service_poll_interval, state_directory, root_directory,
+               cloudtail_path,
                sleep_fn=time.sleep):
     """
     Args:
       config_directory: Directory containing .json config files to monitor.
       config_poll_interval: How often (in seconds) to poll config_directory
           for changes.
       service_poll_interval: How often (in seconds) to restart failed services.
       state_directory: A file will be created in this directory (with the same
           name as the service) when it is running containing its PID and
           starttime.
+      cloudtail_path: Path to the cloudtail binary to use for logging, or None
+          if logging is disabled.
     """
 
     self._config_glob = os.path.join(config_directory, '*.json')
     self._config_poll_interval = config_poll_interval
     self._service_poll_interval = service_poll_interval
     self._state_directory = state_directory
+    self._cloudtail_path = cloudtail_path
 
     self._metadata = {}  # Filename -> _Metadata
     self._services = {}  # Service name -> Filename
     self._stop = False
 
     self._sleep_fn = sleep_fn
 
     self._own_service = service.OwnService(state_directory, root_directory)
 
   def run(self):
@@ skipping 64 matching lines @@
     if config['name'] in self._services:
       LOGGER.error('Duplicate service name "%s" (defined in %s and %s)' % (
           config['name'], self._services[config['name']], filename))
       return
 
     LOGGER.info('Adding new service config for %s', config['name'])
 
     thread = service_thread.ServiceThread(
         self._service_poll_interval,
         self._state_directory,
-        config)
+        config,
+        self._cloudtail_path)
     thread.start()
     thread.start_service()
     self._metadata[filename] = _Metadata(mtime, config, thread)
     self._services[config['name']] = filename
 
   def _config_changed(self, filename, metadata, new_mtime):
     if metadata.config is not None:
       del self._services[metadata.config['name']]
 
     metadata.config = self._load_config(filename)
@@ skipping 11 matching lines @@
       if metadata.thread is not None:
         metadata.thread.stop_service()
       return
 
     LOGGER.info('Updating service config for %s', metadata.config['name'])
 
     if metadata.thread is None:
       metadata.thread = service_thread.ServiceThread(
           self._service_poll_interval,
           self._state_directory,
-          metadata.config)
+          metadata.config,
+          self._cloudtail_path)
       metadata.thread.start()
       metadata.thread.start_service()
     else:
       metadata.thread.restart_with_new_config(metadata.config)
 
     self._services[metadata.config['name']] = filename
 
   def _config_removed(self, metadata):
     LOGGER.info('Removing service config for %s', metadata.config['name'])
 
     del self._services[metadata.config['name']]
 
     metadata.config = None
     metadata.mtime = None
     metadata.thread.stop_service()