Deprecate httpd/keystone.py

Now that we have keystone-wsgi-admin and keystone-wsgi-public
we can deprecate httpd/keystone.py. These 2 are already defined
in setup.cfg pointing to wsgi.py to initialize the application.

Change-Id: Ifcdfcb31e7be18b511a7c586d9ca259bc15bec44
Closes-Bug: 1494922

httpd/keystone.py

@@ -14,12 +14,28 @@
 
 import os
 
+from oslo_log import log
+from oslo_log import versionutils
+
+from keystone.i18n import _LW
 from keystone.server import wsgi as wsgi_server
 
 
 name = os.path.basename(__file__)
+LOG = log.getLogger(__name__)
+
+
+def deprecation_warning():
+    versionutils.report_deprecated_feature(
+        LOG,
+        _LW('httpd/keystone.py is deprecated as of Mitaka'
+            ' in favor of keystone-wsgi-admin and keystone-wsgi-public'
+            ' and may be removed in O.')
+    )
 
 # NOTE(ldbragst): 'application' is required in this context by WSGI spec.
 # The following is a reference to Python Paste Deploy documentation
 # http://pythonpaste.org/deploy/
-application = wsgi_server.initialize_application(name)
+application = wsgi_server.initialize_application(
+    name,
+    post_log_configured_function=deprecation_warning)

keystone/server/wsgi.py

@@ -47,7 +47,7 @@ KEYSTONE_HEADERS = [
 ]
 
 
-def initialize_application(name):
+def initialize_application(name, post_log_configured_function=lambda: None):
     common.configure()
 
     # Log the options used when starting if we're in debug mode...
@@ -56,6 +56,8 @@ def initialize_application(name):
 
     environment.use_stdlib()
 
+    post_log_configured_function()
+
     def loadapp():
         return keystone_service.loadapp(
             'config:%s' % config.find_paste_config(), name)