Charmed MySQL K8s operator

Description

This repository contains a Juju Charm for deploying MySQL on Kubernetes.

To deploy on virtual machines, please use Charmed MySQL VM operator.

Usage

Bootstrap a Kubernetes (e.g. Multipass-based MicroK8s) and create a new model using Juju 2.9+:

juju add-model mysql-k8s
juju deploy mysql-k8s --trust --channel 8.0

Note: the --trust flag is required when relating using mysql_client interface.

Note: the above model must be created on K8s environment. Use another charm for VMs!

To confirm the deployment, you can run:

juju status --watch 1s

Once MySQL starts up, it will be running on the default port (3306).

If required, you can remove the deployment completely by running:

juju destroy-model mysql-k8s --destroy-storage --yes

Note: the --destroy-storage will delete any data persisted by MySQL.

Documentation

This operator provides a MySQL database with replication enabled: one primary instance and one (or more) hot standby replicas. The Operator in this repository is a Python-based framework which wraps MySQL distributed by Ubuntu Jammy providing lifecycle management and handling events (install, configure, integrate, remove, etc).

Please follow the tutorial guide with detailed explanation how to access DB, configure cluster, change credentials and/or enable TLS.

Integrations (relations)

The charm 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. 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

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.

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.

OCI Images

This charm uses pinned and tested version of the charmed-mysql rock.

Security

Security issues in the Charmed MySQL K8s Operator can be reported through LaunchPad. Please do not file GitHub issues about security issues.

Contributing

Please see the Juju SDK docs for guidelines on enhancements to this charm following best practice guidelines, and CONTRIBUTING.md for developer guidance.

License

The Charmed MySQL K8s Operator is distributed under the Apache Software License, version 2.0. It installs/operates/depends on MySQL Community Edition, which is licensed under the GPL License, version 2.

Trademark Notice

MySQL is a trademark or registered trademark of Oracle America, Inc. Other trademarks are property of their respective owners.