Expose named caches as dimensions.

appengine/swarming/swarming_bot/api/os_utilities.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.
 
 """OS specific utility functions.
 
 Includes code:
 - to declare the current system this code is running under.
 - to run a command on user login.
 - to reboot the host.
@@ skipping 501 matching lines @@
   if sys.platform == 'darwin':
     return platforms.osx.get_uptime()
   if sys.platform == 'win32':
     return platforms.win.get_uptime()
   if sys.platform == 'cygwin':
     # Not important.
     return 0.
   return platforms.linux.get_uptime()
 
 
+def get_named_caches():
+  """Returns the list of named caches."""
+  # Strictly speaking, this is a layering violation. This data is managed by
+  # run_isolated.py but this is valuable to expose this as a Swarming bot
+  # dimensions so ¯\_(ツ)_/¯
+  #
+  # Assumptions:
+  # - ../__main__.py calls os.chdir(__file__)
+  # - ../bot_code/bot_main.py specifies
+  #   --named-cache-root os.path.join(botobj.base_dir, 'c') to run_isolated.
+  # - ../client/named_cache.py behavior
+  #
+  # A better implementation would require:
+  # - Access to bot.Bot instance to query bot.base_dir
+  # - Access to named_cache.py to load state.json
+  # - Access to --named-cache-root hardcoded in bot_main.py
+  #
+  # but hey, the following code is 5 lines...
+  try:
+    with open(os.path.join(u'c', u'state.json'), 'rb') as f:
+      return sorted(i[0] for i in json.load(f)['items'])
+  except (IOError, KeyError, OSError):
+    return []
+
+
 class AuthenticatedHttpRequestFailure(Exception):
   pass
 
 
 def authenticated_http_request(service_account, *args, **kwargs):
   """Sends an OAuth2-authenticated HTTP request.
 
   Args:
     service_account: Service account to use. For GCE, the name of the service
       account, otherwise the path to the service account JSON file.
@@ skipping 315 matching lines @@
     u'cpu': [
       cpu_type,
       cpu_type + u'-' + cpu_bitness,
     ],
     u'gpu': get_gpu()[0],
     u'id': [get_hostname_short()],
     u'os': get_os_values(),
     # This value is frequently overridden by bots.cfg via luci-config.
     u'pool': [u'default'],
   }
+  caches = get_named_caches()
+  if caches:
+    dimensions[u'caches'] = caches
   if u'avx2' in cpuinfo.get(u'flags', []):
     dimensions[u'cpu'].append(cpu_type + u'-' + cpu_bitness + u'-avx2')
   if any(u'avx512' in x for x in cpuinfo.get(u'flags', [])):
     dimensions[u'cpu'].append(cpu_type + u'-' + cpu_bitness + u'-avx512')
   if u'none' not in dimensions[u'gpu']:
     hidpi = get_monitor_hidpi()
     if hidpi:
       dimensions[u'hidpi'] = hidpi
 
   machine_type = get_machine_type()
@@ skipping 334 matching lines @@
 
 
 def trim_rolled_log(name):
   try:
     for item in glob.iglob('%s.??' % name):
       os.remove(item)
     for item in glob.iglob('%s.???' % name):
       os.remove(item)
   except Exception as e:
     logging.exception('trim_rolled_log(%s) failed: %s', name, e)