Enable Keystone under Apache by default

Make the default run mode of Keystone HTTPD + mod_wsgi. This will
enable gating on Keystone under mod_wsgi.

Depends On: https://review.openstack.org/#/c/100764/

Change-Id: I4b664a1d6c9bbb1ff999158f3a8c8ab3bd8d891b
diff --git a/README.md b/README.md
index 7185e9d..7eacebd 100644
--- a/README.md
+++ b/README.md
@@ -143,6 +143,8 @@
 Each service that can be run under HTTPD + mod_wsgi also has an override
 toggle available that can be set in your ``local.conf``.
 
+Keystone is run under HTTPD + mod_wsgi by default.
+
 Example (Keystone):
 
     KEYSTONE_USE_MOD_WSGI="True"
diff --git a/lib/keystone b/lib/keystone
index ec124cb..86f1c37 100644
--- a/lib/keystone
+++ b/lib/keystone
@@ -47,7 +47,7 @@
 KEYSTONE_EXTENSIONS=${KEYSTONE_EXTENSIONS:-}
 
 # Toggle for deploying Keystone under HTTPD + mod_wsgi
-KEYSTONE_USE_MOD_WSGI=${KEYSTONE_USE_MOD_WSGI:-False}
+KEYSTONE_USE_MOD_WSGI=${KEYSTONE_USE_MOD_WSGI:-${ENABLE_HTTPD_MOD_WSGI_SERVICES}}
 
 # Select the backend for Keystone's service catalog
 KEYSTONE_CATALOG_BACKEND=${KEYSTONE_CATALOG_BACKEND:-sql}