Blue/green deployments

docker-compose.yml:

name: alias

services:
  shell:
    image: alpine/curl
    command: tail -f /dev/null

  blue:
    image: nginx
    volumes:
      - /tmp/alias/blue.html:/usr/share/nginx/html/index.html:ro

  green:
    image: nginx
    volumes:
      - /tmp/alias/green.html:/usr/share/nginx/html/index.html:ro

blue.html:

blue

green.html:

green

• Startup: docker compose up -d

• Test connectivity

  docker compose exec shell curl blue
  docker compose exec shell curl green

• Create network

  docker network create bluegreen

• Connect shell to network, so it can connect to other containers

  docker network connect bluegreen alias-shell-1

• Set current host

  docker network connect bluegreen alias-blue-1 --alias current

• Test current

  docker compose exec shell curl current
  # blue

• Switch to green

  docker network connect bluegreen alias-green-1 --alias current
  docker network disconnect bluegreen alias-blue-1
  
  docker compose exec shell curl current
  # green