MariaDB¶

The MariaDB container provides the relational database backend for the PHP application. It is configured for persistence, remote connectivity, and flexible overrides through environment variables.

Dockerfile: devops/{env}/mysql/Dockerfile

Persistent data storage¶

Data is stored persistently between container restarts via a volume mount:

volumes:
  - ./devops/prod/mysql:/var/lib/mysql/data

Environment variables¶

All credentials and connection settings are defined in your .env file and injected into the container:

environment:
  - MARIADB_ROOT_PASSWORD=${DB_ROOT_PASSWORD}
  - MARIADB_DATABASE=${DB_NAME}
  - MARIADB_USER=${DB_USER}
  - MARIADB_PASSWORD=${DB_PASSWORD}

Variable	Purpose
`DB_ROOT_PASSWORD`	Root password for MariaDB
`DB_NAME`	Name of the database to create
`DB_USER`	Custom username
`DB_PASSWORD`	Password for the user

Remote connection¶

MariaDB is exposed on the host via port 3307 (mapped from internal 3306):

ports:
  - "3307:3306"

Connect from a local client (e.g., DataGrip):

Setting	Value
Host	`localhost`
Port	`3307`
Username	`${DB_USER}`
Password	`${DB_PASSWORD}`
Database	`${DB_NAME}`

Health check¶

The container runs a health check before dependent services (e.g., PHP) start, preventing connection race conditions on startup:

healthcheck:
  test: ["CMD", "mysqladmin", "ping", "-h", "localhost"]
  interval: 10s
  timeout: 5s
  retries: 5

Service configuration¶

Property	Value
Dockerfile	`devops/{env}/mysql/Dockerfile`
Internal port	`3306` → exposed as `3307` on host
Network	`barberklingen-<site>-network`
Volume	`./devops/prod/mysql:/var/lib/mysql/data`

Troubleshooting¶

Docker network host permission errors¶

Even when networking is correctly configured, MariaDB may refuse connections if the MySQL user was created with 'user'@'localhost' rather than a host matching the Docker network IP range.

Symptom: PHP can reach the MariaDB container by hostname, but authentication fails.

Fix:

Check the Docker network CIDR:

docker network inspect <network-name>

Grant the user access from the Docker IP range:

GRANT ALL PRIVILEGES ON *.* TO 'user'@'172.%' IDENTIFIED BY 'password';
FLUSH PRIVILEGES;

Verify connectivity from another container:

docker exec -it <container-name> php -r "mysqli_connect('<mariadb-container-name>', 'user', 'password') or die(mysqli_connect_error());"