Moves find config to utils because it is useful

This is to prepare for a future patch will will use find
config to load other config files.

Change-Id: Ic9bd9027baf518734c3f51f516651b80d1e752f2

nova/exception.py

@@ -810,8 +810,8 @@ class MalformedRequestBody(NovaException):
     message = _("Malformed message body: %(reason)s")
 
 
-class PasteConfigNotFound(NotFound):
-    message = _("Could not find paste config at %(path)s")
+class ConfigNotFound(NotFound):
+    message = _("Could not find config at %(path)s")
 
 
 class PasteAppNotFound(NotFound):

nova/utils.py

@@ -77,6 +77,29 @@ def import_object(import_str):
         return cls()
 
 
+def find_config(config_path):
+    """Find a configuration file using the given hint.
+
+    :param config_path: Full or relative path to the config.
+    :returns: Full path of the config, if it exists.
+    :raises: `nova.exception.ConfigNotFound`
+
+    """
+    possible_locations = [
+        config_path,
+        os.path.join(FLAGS.state_path, "etc", "nova", config_path),
+        os.path.join(FLAGS.state_path, "etc", config_path),
+        os.path.join(FLAGS.state_path, config_path),
+        "/etc/nova/%s" % config_path,
+    ]
+
+    for path in possible_locations:
+        if os.path.exists(path):
+            return os.path.abspath(path)
+
+    raise exception.ConfigNotFound(path=os.path.abspath(config_path))
+
+
 def vpn_ping(address, port, timeout=0.05, session_id=None):
     """Sends a vpn negotiation packet and returns the server session.
 

nova/wsgi.py

@@ -375,29 +375,7 @@ class Loader(object):
 
         """
         config_path = config_path or FLAGS.api_paste_config
-        self.config_path = self._find_config(config_path)
-
-    def _find_config(self, config_path):
-        """Find the paste configuration file using the given hint.
-
-        :param config_path: Full or relative path to the paste config.
-        :returns: Full path of the paste config, if it exists.
-        :raises: `nova.exception.PasteConfigNotFound`
-
-        """
-        possible_locations = [
-            config_path,
-            os.path.join(FLAGS.state_path, "etc", "nova", config_path),
-            os.path.join(FLAGS.state_path, "etc", config_path),
-            os.path.join(FLAGS.state_path, config_path),
-            "/etc/nova/%s" % config_path,
-        ]
-
-        for path in possible_locations:
-            if os.path.exists(path):
-                return os.path.abspath(path)
-
-        raise exception.PasteConfigNotFound(path=os.path.abspath(config_path))
+        self.config_path = utils.find_config(config_path)
 
     def load_app(self, name):
         """Return the paste URLMap wrapped WSGI application.