Comment 0 for bug 806241

If this is being tracked on another bug, I apologize in advance...

It should be possible to collocate services on the same machine and optionally relate them to one another. This has a very valid use case with regards to openstack. Smaller deployments of only a handful of machines will likely have several (or potentially all) services running on the same machine, while larger deployments will typically isolate services to their own servers and relate them to other services like load balancers, caches, etc.

Currently, the alternative is to develop formulas that deal with a specific set of services as one large service unit and take care of everything within hooks scripts. This is obviously not ideal and makes it difficult to scale.

For example, I'm working on openstack formulas that currently require a minimum of 5 machines:

- nova-compute
- nova-cloud-controller
- glance
- rabbitmq
- mysql

It would be ideal if I could combine rabbitmq and mysql on the same machine as separate services.
nova-cloud-controller is a work-around to this problem as it installs and configures nova-api, nova-schedule, nova-network and nova-objectstore. These should all be handled by separate formulas that relate to one another but currently that would require another 3 machines.
glance is similar in that it sets up the glance-api and glance-registry servers as one unit.