Add support for clusters in the postgresql modules and states

[arthurzenika]

For salt.modules.postgres and salt.states.postgres_* add some support for postgresql clusters.

One would like to be able to say :

frank:
  postgres_database.present:
    cluster: 9.1/main

[jfindlay]

@arthurlogilab, can this issue be closed since your pull request has been merged?

[arthurzenika]

@jfindlay I would leave it open since we can't ask for a specific cluster for a database (yet).

[anitakrueger]

I have been using the postgres_cluster state (thanks for that!) and have just added the correct db_port to connect to in my postgres_database.present states. That way, the database will be created in the correct cluster. Not sure how the postgres_database state would ever know about a cluster...(since that's really just a name/port/data_dir configuration.

[arthurzenika]

@anitakrueger thanks for the heads up on your use of our contribution

@anitakrueger the execution module deb_postgresql has a cluster_list in which you can get the port information from a cluster name. In this way you can avoid relying on storing the port in your configuration.

I'm not sure if you comment is just "we use this" or if it's a bug you're talking about. Can you be more specific ?