MySQL

Towbar’s mysql preset runs the reviewed MySQL 8.4 image on amd64 or arm64. It listens on port 3306, stores data in /var/lib/mysql, and verifies readiness with an authenticated mysqladmin ping.

Declare the resource

.towbar/resources/mysql.resource.yml

id: mysql
name: MySQL
type: mysql
container:
  network: application
  networkAlias: mysql
  resources:
    cpus: 1
    memory: 1g
access:
  sshTunnel:
    hostPort: 13306
secrets:
  runtime:
    - MYSQL_ROOT_PASSWORD
    - MYSQL_DATABASE
    - MYSQL_USER
    - MYSQL_PASSWORD
environments:
  production:
    server: 192.0.2.10

MYSQL_ROOT_PASSWORD is required by Towbar. The other three variables ask the image to create a named application database and non-root user on the first initialization.

Variable	Purpose
`MYSQL_ROOT_PASSWORD`	Root credential used by Towbar health and recovery tools
`MYSQL_DATABASE`	Application database created on an empty data volume
`MYSQL_USER`	Non-root application user
`MYSQL_PASSWORD`	Password for the application user

Use different values for the root and application passwords.

Connect from an app

Containers on the application network can reach mysql:3306. Store the application connection URL or individual fields in the app’s runtime secrets. The optional tunnel exposes server-local port 13306 only through SSH.

Initialization and credential changes

The initialization variables do not reconcile an existing data volume. Create, rename, or alter users and databases with SQL first. Update the corresponding Towbar values only after the database accepts the new credentials.

Back up and restore

Towbar uses mysqldump for a logical export and restores it with the MySQL client into a fresh target volume. Recovery requires MySQL major version 8. Continue with Database backups and Database restores.

Overview

Database guides

Data protection

Declare the resource

Connect from an app

Initialization and credential changes

Back up and restore

​Declare the resource

​Connect from an app

​Initialization and credential changes

​Back up and restore

Declare the resource

Connect from an app

Initialization and credential changes

Back up and restore