Interfaces/endpoints

Charmed MySQL K8s supports modern mysql_client and legacy mysql interfaces (in a backward compatible mode).

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

Modern interfaces

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

Modern mysql_client interface (database endpoint):

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

# Deploy Charmed MySQL cluster with 3 nodes
juju deploy mysql-k8s -n 3 --trust --channel 8.0

# Deploy the relevant charms, e.g. mysql-test-app
juju deploy mysql-test-app

# Relate MySQL with your application
juju relate mysql-k8s:database mysql-test-app:database

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

# Example of the properly established relation:
# > Relation provider      Requirer                 Interface     Type
# > mysql-k8s:database     mysql-test-app:database  mysql_client  regular

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

Note: In order to relate with this charm, every table created by the related application must have a primary key. This is required by the group replication plugin enabled in this charm.

Legacy interfaces

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

Legacy mysql interface (mysql and mysql-root endpoints):

This charm supports legacy interface mysql (endpoint mysql and mysql-root). It was a popular interface used by some legacy charms (e.g. “MariaDB”, “OSM MariaDB”, “Percona Cluster” and “Mysql Innodb Cluster”), often in cross-model relations:

juju deploy mysql-k8s --trust --channel 8.0
juju config mysql-k8s mysql-interface-database=wordpress mysql-interface-user=wordpress
juju deploy wordpress-k8s
juju relate mysql-k8s:mysql wordpress-k8s:db

Note: The endpoint mysql-root provides the same legacy interface mysql with MySQL root-level privileges. It is NOT recommended to use it from security point of view.