I have a blueprint for external mongodb support (https://blueprints.launchpad.net/fuel/+spec/external-mongodb-support). Patches are ready and tested, but we need a testing ci for this feature. It could be a single job that setups mongo in single node or mongo with replicaset depending on environment which we are want to test. If it's a HA mode, we deploy mongo with replicaset, else we deploy only one node.
To deploy mongo we can use our puppet scripts in fuel-library (we need in mongodb module only). To use it we should pass the same parameter to it as it does during fuel deploy. If we deploy HA mode we pass mongodb_bind_address, ceilometer_metering_secret, ceilometer_db_password, ceilometer_replset_members for primary mongo and mongodb_bind_address for another mongo nodes. In simple mode we should deploy only one mongo node as primary.
Then we should pass mongo credentials to job that will test deploy cluster with external mongo.
Ivan, currently we're trying to not to support anything we're not working with directly.
So I can provide you access to our puppet manifests to add/use modules for mongo and help to setup notifications from zabbix for this mongo to you or your team.
But unfortunately we can't support any thing you're developing with.