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

Find all details about default and extra DB user roles in “Charm Users explanations”.

Legacy interfaces

Note: Legacy relations are deprecated and will be discontinued on future releases. Usage should be avoided. Check the legacy interfaces implementation limitations in the “Legacy charm” document.

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.