docker-compose.yml

# This docker-compose file starts MySQL and Flyway in a bridge network. When the Flyway container becomes active, it 
# creates the tables in the MySQL database and populates them.
version: '3.7'

services:
  # This section defines the mysql service, named "db". The name can be referenced in things like URLs. So, we can tell
  # Flyway to find the database at jdbc:mysql://db and Docker Compose will fill in the network details.
  db:
    container_name: mysql
    image: mysql:latest
    restart: always
    environment:
      # These environment variables cause MySQL to create the users username/password
      # root/root and dev/dev. It also creates a database named jeep.
      MYSQL_ROOT_USER: root
      MYSQL_ROOT_PASSWORD: root
      MYSQL_DATABASE: jeep
      MYSQL_USER: jeep
      MYSQL_PASSWORD: jeep
    ports:
      # Forward host port 8306 to guest port 3306 (MySQL default port). This means that applications external to the
      # container cluster can access MySQL within the container on port 8306 and the requests are forwarded to port 3306
      # within the cluster.
      - "8306:3306"
    networks:
      - jeep

  # Flyway is used to create the tables and populate them with data. The migration files are found in 
  # src/functional-test/resources. The schema is applied first to create the tables (V1.0__Jeep_Schema.sql) and 
  # then the data is applied in V1.1__Jeep_Data.sql. Note that these files are also applied for each functional
  # (integration) test using the @Sql annotation in the functional test classes.
  flyway:
    container_name: flyway
    image: flyway/flyway:latest
    command: migrate
    
    # These environment variables are used in ./flyway/conf/flyway.conf to tell Flyway which database to connect to.
    environment:
      FLYWAY_URL: jdbc:mysql://db
      FLYWAY_SCHEMAS: jeep
      FLYWAY_USER: jeep
      FLYWAY_PASSWORD: jeep
      
      # Set the retry count to let the database come up before Flyway gives up.
      FLYWAY_CONNECT_RETRIES: 60
    volumes:
      # Create a volume between ./src/functional-test/resources/flyway/migrations in the host and /flyway/sql in the 
      # container. This allows Flyway to grab the migration files from the default location.
      - ./src/test/resources/flyway/migrations:/flyway/sql
      
      # Create a volume between ./src/functional-test/resources/flyway/conf on the host and /flyway/conf in the 
      # container. This allows Flyway to read configuration fron the default configuration location.
      - ./src/test/resources/flyway/conf:/flyway/conf
    depends_on:
      - db
    networks:
      - jeep

# Create a bridge network between the MySQL container and the Flyway container.
networks:
  jeep:
    driver: bridge
    name: jeep-to-jeep