Send authorization headers when calling Swarming backend.

appengine/swarming/swarming_bot/config/bot_config.py

 # coding: utf-8
 # Copyright 2013 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 file is meant to be overriden by the server's specific copy.
 
 You can upload a new version via /restricted/upload/bot_config.
 
 There's 3 types of functions in this file:
@@ skipping 45 matching lines @@
   tasks.
 
   See https://code.google.com/p/swarming/wiki/SwarmingMagicValues.
 
   Arguments:
   - botobj: bot.Bot instance or None.
   """
   return os_utilities.get_state()
 
 
+def get_authentication_headers(bot):
+  """Returns authentication headers and their expiration time.
+
+  The returned headers will be passed with each HTTP request to the Swarming
+  server (and only Swarming server). The bot will use the returned headers until
+  they are close to expiration (usually 6 min, see AUTH_HEADERS_EXPIRATION_SEC
+  in remote_client.py), and then it'll attempt to refresh them by calling
+  get_authentication_headers again.
+
+  Can be used to implement per-bot authentication. If no headers are returned,
+  the server will use only IP whitelist for bot authentication.
+
+  May be called by different threads, but never concurrently.
+
+  Arguments:
+  - botobj: bot.Bot instance.
+
+  Returns:
+    Tuple (dict with headers or None, unix timestamp of when they expire).
+  """
+  return (None, None)
+
+
 ### Hooks
 
 
 def on_bot_shutdown(bot):
   """Hook function called when the bot shuts down, usually rebooting.
 
   It's a good time to do other kinds of cleanup.
 
   Arguments:
   - bot: bot.Bot instance.
@@ skipping 52 matching lines @@
 def setup_bot(bot):
   """Does one time initialization for this bot.
 
   Returns True if it's fine to start the bot right away. Otherwise, the calling
   script should exit.
 
   Example: making this script starts automatically on user login via
   os_utilities.set_auto_startup_win() or os_utilities.set_auto_startup_osx().
   """
   return True