Add generate-config option to kolla-ansible

In order for the ansible configuration to be consumable,
we need to be able to generate it without deploying anything.

Change-Id: I2bbdd74d62d00f509a4fa5e4100906ed658d3974
Implements: blueprint generate-config

tools/kolla-ansible

@@ -38,15 +38,16 @@ Options:
     --verbose, -v                    Increase verbosity of ansible-playbook
 
 Commands:
-    prechecks    Do pre-deployment checks for hosts
+    prechecks           Do pre-deployment checks for hosts
     mariadb_recovery    Recover a completely stopped mariadb cluster
-    deploy       Deploy and start all kolla containers
-    cleanup      Cleanup containers, volumes and host
-    post-deploy  Do post deploy on deploy node
-    pull         Pull all images for containers (only pulls, no running container changes)
-    reconfigure  Reconfigure OpenStack service
-    certificates Generate self-signed certificate for TLS *For Development Only*
-    upgrade      Upgrades existing OpenStack Environment
+    deploy              Deploy and start all kolla containers
+    cleanup             Cleanup containers, volumes and host
+    post-deploy         Do post deploy on deploy node
+    pull                Pull all images for containers (only pulls, no running container changes)
+    reconfigure         Reconfigure OpenStack service
+    certificates        Generate self-signed certificate for TLS *For Development Only*
+    upgrade             Upgrades existing OpenStack Environment
+    genconfig           Generate configuration files for enabled OpenStack services
 EOF
 }
 
@@ -161,6 +162,10 @@ case "$1" in
         ACTION="Generate TLS Certificates"
         PLAYBOOK="${BASEDIR}/ansible/certificates.yml"
         ;;
+(genconfig)
+        ACTION="Generate configuration files for enabled OpenStack services"
+        EXTRA_OPTS="$EXTRA_OPTS -e action=config"
+        ;;
 (*)     usage
         exit 0
         ;;