MySQL Operator for K8s

Description

The MySQL operator provides an open-source relational database management system (RDBMS). This repository contains a Juju Charm for deploying MySQL on Kubernetes clusters.

Deployment instructions

Create a Juju model for your operators, say "mysql-k8s"

$ juju add-model mysql-k8s

Deploy a single unit of MySQL using its default configuration

$ juju deploy ./mysql-k8s.charm --resource mysql-image=ubuntu/mysql:latest

As in this example we did not specify the password for the root user, the charm will generate one, and you can get it executing:

$ juju show-unit mysql-k8s/0

The password will be the value for the key MYSQL_ROOT_PASSWORD

If required, you can remove the deployment completely:

$ juju destroy-model -y mysql-k8s --no-wait --force --destroy-storage

Note the --destroy-storage will delete any data stored by MySQL in its persistent store.

Config

This charm implements the following configs:

• MYSQL_USER: Create a new user with superuser privileges. This is used in conjunction with MYSQL_PASSWORD.
• MYSQL_PASSWORD: Set the password for the MYSQL_USER user.
• MYSQL_DATABASE: Set the name of the default database.

And you can use it, like this:

$  juju deploy ./mysql-k8s.charm --config MYSQL_ROOT_PASSWORD=SuperSecretPassword --config MYSQL_USER=JohnDoe --config MYSQL_PASSWORD=SuperSecretUserPassword --config MYSQL_DATABASE=default_database --resource mysql-image=ubuntu/mysql:lates

Relations

This charm provides a database relation so you can integrate this charm with others charms that requires a MySQL database.

Developing

Create and activate a virtualenv with the development requirements:

$ virtualenv -p python3 venv
$ source venv/bin/activate
$ pip install -r requirements-dev.txt
    ```

### Setup

A typical setup using [snaps](https://snapcraft.io/), for deployments to a [microk8s](https://microk8s.io/) cluster can be done using the following commands

```bash
$ sudo snap install microk8s --classic
$ microk8s.enable dns storage registry dashboard
$ sudo snap install juju --classic
$ juju bootstrap microk8s microk8s
$ juju create-storage-pool operator-storage kubernetes storage-class=microk8s-hostpath

Build

Install the charmcraft tool

$ sudo snap install charmcraft

Build the charm in this git repository

$ charmcraft build

Testing

The Python operator framework includes a very nice harness for testing operator behaviour without full deployment. Just run_tests:

./run_tests