How to integrate with another application¶
Integrations, also known as “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 with both charmed and non-charmed applications.
For developer information about how to integrate your own charmed application with PostgreSQL, see How to integrate PostgreSQL with your charm.
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.
Note
You can see which existing charms are compatible with PostgreSQL in the Integrations tab on Charmhub.
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¶
Caution
Note that this interface is deprecated. See 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
In the case of connecting with a non-charmed application, <charm> would be data-integrator.
See also: How to manage passwords
Request a custom username¶
Charms can request a custom username to be used in their relation with PostgreSQL 16.
The simplest way to test it is to use requested-entities-secret field via the data-integrator charm.
Example
$ juju deploy postgresql-k8s --channel 16/edge --trust
$ juju add-secret myusername mylogin=mypassword
secret:d5l3do605d8c4b1gn9a0
$ juju deploy data-integrator --channel latest/edge --config database-name=mydbname --config requested-entities-secret=d5l3do605d8c4b1gn9a0
Deployed "data-integrator" from charm-hub charm "data-integrator", revision 307 in channel latest/edge on ubuntu@24.04/stable
$ juju grant-secret d5l3do605d8c4b1gn9a0 data-integrator
$ juju relate postgresql-k8s data-integrator
$ juju run data-integrator/leader get-credentials
...
postgresql-k8s:
database: mydbname
username: mylogin
password: mypassword
uris: postgresql://mylogin:mypassword@10.218.34.199:5432/mydbname
version: "16.11"
...
$ psql postgresql://mylogin:mypassword@10.218.34.199:5432/mydbname -c "SELECT SESSION_USER, CURRENT_USER"
session_user | current_user
--------------+---------------------------
mylogin | charmed_mydbname_owner
(1 row)
For more technical details, see the description of the postgresql_client interface