Juju Operator Framework Charm Interface for MySQL & MariaDB Relations

To use this interface in your Juju Operator Framework charm, instruct charmcraft to embed it into your built Operator Framework charm by adding ops-lib-mysql to your requirements.txt file::

ops
ops-lib-mysql

Your charm needs to declare its use of the interface in its metadata.yaml file:

requires:
  db:
    interface: mysql
    limit: 1  # Most charms only handle a single MySQL Application.

Your charm needs to bootstrap it and handle events:

from opslib.mysql import MySQLClient, MySQLRelationEvent


class MyCharm(ops.charm.CharmBase):
    _state = ops.framework.StoredState()

    def __init__(self, *args):
        super().__init__(*args)
        self._state.set_default(
            db_available=False, db_conn_str=None, db_host=None, db_port=None, db_name=None,
            db_user=None, db_password=None, db_root_password=None,
        )
        self.db = MySQLClient(self, 'db')  # 'db' relation in metadata.yaml
        self.framework.observe(self.db.on.database_changed, self._on_database_changed)

    def _on_database_changed(self, event: MySQLRelationEvent):
        self._state.db_available = event.is_available  # Boolean flag
        self._state.db_conn_str = event.connection_string  # host={host} port={port} ...
        self._state.db_host = event.host
        self._state.db_port = event.port
        self._state.db_name = event.database
        self._state.db_user = event.user
        self._state.db_password = event.password
        self._state.db_root_password = event.root_password