Use ConfigOpts.find_file() to locate policy.json

Use cfg's new helper method to find policy config file. The basic
behavior is "look alongside the config file" with a fall back to
the standard default config paths.

Change-Id: I763097107c53fc9b7d4e783ee92bf16989d92cff

nova/policy.py

@@ -17,6 +17,8 @@
 
 """Policy Engine For Nova"""
 
+import os.path
+
 from nova.common import policy
 from nova import exception
 from nova import flags
@@ -52,7 +54,11 @@ def init():
     global _POLICY_PATH
     global _POLICY_CACHE
     if not _POLICY_PATH:
-        _POLICY_PATH = utils.find_config(FLAGS.policy_file)
+        _POLICY_PATH = FLAGS.policy_file
+        if not os.path.exists(_POLICY_PATH):
+            _POLICY_PATH = FLAGS.find_file(_POLICY_PATH)
+        if not _POLICY_PATH:
+            raise exception.ConfigNotFound(path=FLAGS.policy_file)
     utils.read_cached_file(_POLICY_PATH, _POLICY_CACHE,
                            reload_func=_set_brain)
 

nova/tests/fake_flags.py

@@ -43,4 +43,3 @@ FLAGS.set_default('flat_network_bridge', 'br100')
 FLAGS.set_default('sqlite_synchronous', False)
 flags.DECLARE('policy_file', 'nova.policy')
 flags.DECLARE('compute_scheduler_driver', 'nova.scheduler.multi')
-FLAGS.set_default('policy_file', 'nova/tests/policy.json')

nova/utils.py

@@ -1332,6 +1332,7 @@ def read_cached_file(filename, cache_info, reload_func=None):
     """
     mtime = os.path.getmtime(filename)
     if not cache_info or mtime != cache_info.get('mtime'):
+        LOG.debug(_("Reloading cached file %s") % filename)
         with open(filename) as fap:
             cache_info['data'] = fap.read()
         cache_info['mtime'] = mtime