Add documentation on how to use MySQL instead of PostgreSQL. (#567)

Co-authored-by: Kévin Dunglas <kevin@dunglas.fr>
Co-authored-by: Borislav Kosun <kosun.b@yandex.com>
Co-authored-by: Maxime Helias <maximehelias16@gmail.com>

README.md

@@ -37,8 +37,9 @@ with [FrankenPHP](https://frankenphp.dev) and [Caddy](https://caddyserver.com/)
 5. [Debugging with Xdebug](docs/xdebug.md)
 6. [TLS Certificates](docs/tls.md)
 7. [Using a Makefile](docs/makefile.md)
-8. [Troubleshooting](docs/troubleshooting.md)
-9. [Updating the template](docs/updating.md)
+8. [Using MySQL instead of PostgreSQL](docs/mysql.md)
+9. [Troubleshooting](docs/troubleshooting.md)
+10. [Updating the template](docs/updating.md)
 
 ## License
 

docs/mysql.md

@@ -0,0 +1,72 @@
+# Using MySQL
+
+The Docker configuration of this repository is extensible thanks to Flex recipes. By default, the recipe installs PostgreSQL.
+If you prefer to work with MySQL, follow these steps:
+
+First, install the `symfony/orm-pack` package as described: `docker compose exec php composer req symfony/orm-pack`
+
+## Docker Configuration
+Change the database image to use MySQL instead of PostgreSQL in `compose.yaml`:
+
+```diff
+###> doctrine/doctrine-bundle ###
+-   image: postgres:${POSTGRES_VERSION:-15}-alpine
++   image: mysql:${MYSQL_VERSION:-8}
+    environment:
+-     POSTGRES_DB: ${POSTGRES_DB:-app}
++     MYSQL_DATABASE: ${MYSQL_DATABASE:-app}
+      # You should definitely change the password in production
++     MYSQL_RANDOM_ROOT_PASSWORD: "true"
+-     POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-!ChangeMe!}
++     MYSQL_PASSWORD: ${MYSQL_PASSWORD:-!ChangeMe!}
+-     POSTGRES_USER: ${POSTGRES_USER:-app}
++     MYSQL_USER: ${MYSQL_USER:-app}
+    volumes:
+-     - database_data:/var/lib/postgresql/data:rw
++     - database_data:/var/lib/mysql:rw
+      # You may use a bind-mounted host directory instead, so that it is harder to accidentally remove the volume and lose all your data!
+-     # - ./docker/db/data:/var/lib/postgresql/data:rw
++     # - ./docker/db/data:/var/lib/mysql:rw
+###< doctrine/doctrine-bundle ###
+```
+
+Depending on the database configuration, modify the environment in the same file at `services.php.environment.DATABASE_URL`
+```
+DATABASE_URL: mysql://${MYSQL_USER:-app}:${MYSQL_PASSWORD:-!ChangeMe!}@database:3306/${MYSQL_DATABASE:-app}?serverVersion=${MYSQL_VERSION:-8}&charset=${MYSQL_CHARSET:-utf8mb4}
+```
+
+Since we changed the port, we also have to define this in the `compose.override.yaml`:
+```diff
+###> doctrine/doctrine-bundle ###
+  database:
+    ports:
+-     - "5432"
++     - "3306"
+###< doctrine/doctrine-bundle ###
+```
+
+Last but not least, we need to install the MySQL driver in `Dockerfile`:
+```diff
+###> doctrine/doctrine-bundle ###
+-RUN install-php-extensions pdo_pgsql
++RUN install-php-extensions pdo_mysql
+###< doctrine/doctrine-bundle ###
+```
+
+## Change Environment
+Change the database configuration in `.env`:
+
+```dotenv 
+DATABASE_URL=mysql://${MYSQL_USER:-app}:${MYSQL_PASSWORD:-!ChangeMe!}@database:3306/${MYSQL_DATABASE:-app}?serverVersion=${MYSQL_VERSION:-8}&charset=${MYSQL_CHARSET:-utf8mb4}
+```
+
+## Final steps
+Rebuild the docker environment:
+```shell
+docker compose down --remove-orphans && docker compose build --pull --no-cache
+```
+
+Test your setup:
+```shell
+docker compose exec php bin/console dbal:run-sql -q "SELECT 1" && echo "OK" || echo "Connection is not working"
+```