deprecate ceilometer api

adds deprecation warning at ceilometer api startup, and updates
documentation, as well as release notes.
API is still in place, for now.

Change-Id: Ib88957001de2a61f9625ca5584a2129216647841

ceilometer/api/app.py

@@ -107,6 +107,8 @@ def load_app(conf):
     APPCONFIGS[configkey] = conf
 
     LOG.info("Full WSGI config used: %s", cfg_file)
+    LOG.warning("Note: Ceilometer API is deprecated; use APIs from "
+                "Aodh (alarms), Gnocchi (metrics) and/or Panko (events).")
     return deploy.loadapp("config:" + cfg_file,
                           global_conf={'configkey': configkey})
 

doc/source/webapi/v2.rst

@@ -2,6 +2,15 @@
  V2 Web API
 ============
 
+.. note::
+
+   The Ceilometer API is deprecated.  Use the APIs from Aodh_ (alarms),
+   Gnocchi_ (metrics), and/or Panko_ (events).
+
+.. _Aodh: http://docs.openstack.org/developer/aodh/
+.. _Panko: http://docs.openstack.org/developer/panko/
+
+
 Resources
 =========
 

releasenotes/notes/ceilometer-api-deprecate-862bfaa54e80fa01.yaml

@@ -0,0 +1,5 @@
+---
+deprecations:
+  - Ceilometer API is deprecated. Use the APIs from Aodh (alarms),
+    Gnocchi (metrics), and/or Panko (events).
+