Charmed PostgreSQL K8s How-To | Integrate with another application

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Note: All commands are written for juju >= v.3.0

If you are using an earlier version, check the Juju 3.0 Release Notes.

How to integrate with another application

Integrations (formerly “relations”) are connections between two applications with compatible endpoints. These connections simplify the creation and management of users, passwords, and other shared data.

This guide shows how to integrate Charmed PostgreSQL K8s with both charmed and non-charmed applications.

For developer information about how to integrate your own charmed application with PostgreSQL, see Development > How to integrate with your charm.

Summary

Integrate with a charmed application

Integrations with charmed applications are supported via the modern postgresql_client interface, and the legacy psql interface from the original version of the charm.

You can see which charms are compatible with PostgreSQL in the Integrations tab.

Modern postgresql_client interface

To integrate, run

juju integrate postgresql-k8s:database <charm>

To remove the integration, run

juju remove-relation postgresql-k8s <charm>

Legacy pgsql interface

Note that this interface is deprecated. See more information in Explanation > Legacy charm.

Using the mattermost-k8s charm as an example, an integration with the legacy interface could be created as follows:

juju integrate postgresql-k8s:db mattermost-k8s:db

Extended permissions can be requested using the db-admin endpoint:

juju integrate postgresql-k8s:db-admin mattermost-k8s:db

Integrate with a non-charmed application

To integrate with an application outside of Juju, you must use the data-integrator charm to create the required credentials and endpoints.

Deploy data-integrator:

juju deploy data-integrator --config database-name=<name>

Integrate with PostgreSQL K8s:

juju integrate data-integrator postgresql-k8s

Use the get-credentials action to retrieve credentials from data-integrator:

juju run data-integrator/leader get-credentials

Rotate application passwords

To rotate the passwords of users created for integrated applications, the integration should be removed and created again. This process will generate a new user and password for the application.

juju remove-relation <charm> postgresql-k8s
juju integrate <charm> postgresql-k8s

<charm> can be data-integrator in the case of connecting with a non-charmed application.

Internal operator user

The operator user is used internally by the Charmed PostgreSQL K8s Operator. The set-password action can be used to rotate its password.

To set a specific password for the operator user, run

juju run postgresql-k8s/leader set-password password=<password>

To randomly generate a password for the operator user, run

juju run postgresql-k8s/leader set-password