Charmed PostgreSQL Explanations - Interfaces/endpoints


The charm supports modern postgresql_client and legacy pgsql interfaces (in a backward compatible mode).

Note: do NOT relate both modern and legacy interfaces simultaneously!

Modern interfaces

This charm provides modern ‘postgresql_client’ interface. Applications can easily connect PostgreSQL using ‘data_interfaces’ library from ‘data-platform-libs’.

Modern postgresql_client interface (database endpoint):

Adding a relation is accomplished with juju relate (or juju integrate for Juju 3.x) via endpoint database. Example:

# Deploy Charmed PostgreSQL cluster with 3 nodes
juju deploy postgresql -n 3 --channel 14

# Deploy the relevant application charms
juju deploy mycharm

# Relate PostgreSQL with your application
juju relate postgresql:database mycharm:database

# Check established relation (using postgresql_client interface):
juju status --relations

# Example of the properly established relation:
# > Relation provider      Requirer          Interface          Type
# > postgresql:database    mycharm:database  postgresql_client  regular

Legacy interfaces

Note: Legacy relations are deprecated and will be discontinued on future releases. Usage should be avoided.

Legacy pgsql interface (db and db-admin endpoints):

This charm supports legacy interface pgsql from the previous PostgreSQL charm:

juju relate postgresql:db mailman3-core
juju relate postgresql:db-admin landscape-server

Note: The endpoint db-admin provides the same legacy interface pgsql with PostgreSQL admin-level privileges. It is NOT recommended to use it from security point of view.