1. what

Generic description of pluggable stack Such a stacks is designed for easy integration with other stacks. Each stack handles a specific service, such as a database service for example.

2. How

Each Docker Compose file contains a network definition like this:

networks:
  php_network2:							# Define a network, Changes this in case of external: true
    external: false					# See 1) explanation below
    name: php_network2
    driver: bridge 
    ipam:
      config:
        - subnet: ${FIXED_SUBNET}
		
services:
  mariadb:
    image: mariadb:10.7.8
    restart: "no"
    networks:    
        php_network2:                       # Use this Network
            ipv4_address: ${FIXED_IP}       # Use a fixed IP address for this container service
    environment:
      MARIADB_ROOT_PASSWORD: root
      MARIADB_DATABASE: docker
      MARIADB_USER: docker
      MARIADB_PASSWORD: docker
    ports:
      - "9004:3306"
    volumes:
      - mariadb:/var/lib/mysql
     

Setting the external: true defines an external network, allowing multiple Docker stack files to work together. This works in combination with a .env file, which should contain:

• FIXED_IP
• IXED_SUBNET

  Note: If external: false(default) Docker Compose automatically creates an internal network using the IP defined in .env. Such a service can not reach a service that is not defined in the same file!

Instructions

To connect services to the same network, each service must use the networks setting and a unique FIXED_IP. Make the following changes in all Docker Compose files:

• Set external: true in the network definition.
• Use the same network name (e.g., php_network) across all Docker Compose files.
• Make sure the same network Subnets is used (defined in .env file, make sure all services us this file)
• Ensure the same subnet is used (defined in the .env file).
• Manually create the network before starting any services (make sure to use the correct subnet).
  • Example: docker network create --subnet=${FIXED_SUBNET} php_network
  • Example delete : docker network rm php_network
  • Other example : docker network ls # Displays networks
  • Other example : docker network prune # CAREFUL removes all unused!!
    

Optional tests

• Optional Test, if both are on the same network: docker network inspect php_network
• Optional Test, if the cor rect IP address inside the container is used, enter: hostname -I

version 1.0