Use KEYSTONE_SERVICE_URI consistently

lib/keystone builds KEYSTONE_SERVICE_URI so that other services
don't need to reconstruct the identity URI. Many services already
use it, but some parts were still building the identity URI from
the different parts.

This will allow changing the identity URI to include a path
(e.g., to http://<host>/identity) in 1 place rather than in
multiple places.

Change-Id: I58cbdbe591d8869807545e0815480fc3375e0479
diff --git a/lib/tempest b/lib/tempest
index d95a9f5..25db046 100644
--- a/lib/tempest
+++ b/lib/tempest
@@ -17,7 +17,7 @@
 #   - ``PUBLIC_NETWORK_NAME``
 #   - ``VIRT_DRIVER``
 #   - ``LIBVIRT_TYPE``
-#   - ``KEYSTONE_SERVICE_PROTOCOL``, ``KEYSTONE_SERVICE_HOST`` from lib/keystone
+#   - ``KEYSTONE_SERVICE_URI``, ``KEYSTONE_SERVICE_URI_V3`` from lib/keystone
 #
 # Optional Dependencies:
 #
@@ -257,7 +257,7 @@
     iniset $TEMPEST_CONFIG volume build_timeout $BUILD_TIMEOUT
 
     # Identity
-    iniset $TEMPEST_CONFIG identity uri "$KEYSTONE_SERVICE_PROTOCOL://$KEYSTONE_SERVICE_HOST:5000/v2.0/"
+    iniset $TEMPEST_CONFIG identity uri "$KEYSTONE_SERVICE_URI/v2.0/"
     iniset $TEMPEST_CONFIG identity uri_v3 "$KEYSTONE_SERVICE_URI_V3"
     iniset $TEMPEST_CONFIG identity user_lockout_failure_attempts $KEYSTONE_LOCKOUT_FAILURE_ATTEMPTS
     iniset $TEMPEST_CONFIG identity user_lockout_duration $KEYSTONE_LOCKOUT_DURATION