OSprofiler initialization method

Added init_from_conf method, that takes service configuration
and initializes notifier. This allows initialization to be
handled in osprofiler instead of projects/services. Added
oslo.messaging dependency.

Change-Id: I77d0d3b5e9e725507916724dcd28d5fbc6f7f5c7

osprofiler/initializer.py

@@ -0,0 +1,42 @@
+# Copyright 2016 Mirantis Inc.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import oslo_messaging
+
+from osprofiler import notifier
+from osprofiler import web
+
+
+def init_from_conf(conf, context, project, service, host):
+    """Initialize notifier from service configuration
+
+    :param conf: service configuration
+    :param context: request context
+    :param project: project name (keystone, cinder etc.)
+    :param service: service name that will be profiled
+    :param host: hostname or host IP address that the service will be
+                 running on.
+    """
+    connection_str = conf.profiler.connection_string
+    _notifier = notifier.create(
+        connection_str,
+        messaging=oslo_messaging,
+        context=context,
+        transport=oslo_messaging.get_transport(conf),
+        project=project,
+        service=service,
+        host=host)
+    notifier.set(_notifier)
+    web.enable(conf.profiler.hmac_keys)

requirements.txt

@@ -1,3 +1,4 @@
 six>=1.9.0 # MIT
+oslo.messaging>=5.2.0 # Apache-2.0
 oslo.utils>=3.4.0 # Apache-2.0
 WebOb>=1.2.3 # MIT