The elasticsearchrelation package implements a Juju elasticsearch relation.

The httprelation package can be used in a charm that uses a relation with interface type "http".

The httpservice package provides a way to run a simple HTTP server service as a charm.

The mongodbrelation package implements a Juju mongodb relation.

The resource package provides your charm access to Juju resources.

The service packge provides a way for a charm to start and stop a service that runs independently of the charm hooks.

The simplerelation package implements a generic simple relation where the provider units each make a set of attributes available, and the requirer units can see those attributes.