A simple firewall Docker image based on debian slim to be used in Docker Compose stacks

Procedure:

• Edit docker-compose.firewall.yaml to set your main service (as a depends_on) and add your firewall rules
• Add in your docker compose stack using something like docker-compose -f docker-compose.yaml -f docker-compose.firewall.yaml <command>
• You can 'test' the configuration user: docker-compose -f docker-compose.yaml -f docker-compose.firewall.yaml config