Add tracer for sqlalchemy

To use it in your code you should add 2 sqlalchemy engine event listeners

import sqlalchemy
from sqlalchemy import event as sa_event
from osprofiler import sqlalchemy as sa_profiler

engine = sqlaclhemy.create_engine('your_db_host')

sa_profiler.add_tracing(sqlalchemy, engine, 'your_service')

osprofiler/sqlalchemy.py

@@ -0,0 +1,45 @@
+# Copyright 2013 OpenStack Foundation.
+# 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.
+
+from osprofiler import profiler
+
+
+def before_execute(name):
+    """Add listener that will send trace info before sql executed."""
+    def handler(conn, clauseelement, multiparams, params):
+        p = profiler.get_profiler()
+        if p:
+            info = {"db.statement": str(clauseelement),
+                    "db.multiparams": str(multiparams),
+                    "db.params": str(params)}
+            p.start(name, info=info)
+
+    return handler
+
+
+def after_execute():
+    """Add listener that will send trace info after sql executed."""
+    def handler(conn, clauseelement, multiparams, params, result):
+        p =  profiler.get_profiler()
+        if p:
+            p.stop(info={"db.result": str(result)})
+
+    return handler
+
+
+def add_tracing(sqlalchemy, engine, name):
+    """Add tracing to all sqlalchemy calls."""
+    sqlalchemy.event.listen(engine, 'before_execute', before_execute(name))
+    sqlalchemy.event.listen(engine, 'after_execute', after_execute())