HA-enablement in OpenStack chef cookbooks

As discussed in our meeting here (http://eavesdrop.openstack.org/meetings/openstack_chef/2015/openstack_chef.2015-05-04-14.32.log.html) we want to include some kind of HA option in our official cookbooks for OpenStack. The architecture presented from suse here (http://www.slideshare.net/adamspiers/ha-cookbooksupstream) could be seen as one possible solution with external cookbooks. The goal should be to define some triggers and adapter points that allow the usage of such external services and cookbooks in combination with ours. From my point of view we need to start with defining some attributes, that allow the usage of a HA-database and -message-queue. After that we should take care of the proper setting for neutron to allow replication of the needed services and namespaces. while working on that we can try to focus on handovers for cookbooks for services like pacemaker or keepalived etc. and try to make our definitions as generic as possible.