Docker Compose explained

Compose describes one or more services in a YAML file. The following is a standalone tutorial example, not a copy of a production stack.

services:
  demo-web:
    image: nginx:stable-alpine
    container_name: demo-web
    restart: unless-stopped
    ports:
      - "8080:80"
    volumes:
      - ./site:/usr/share/nginx/html:ro

Key	Meaning
`services`	Container definitions
`image`	Image to pull
`container_name`	Human-friendly name
`restart`	Restart policy
`ports`	Host-to-container port mapping
`volumes`	Bind mount or persistent storage
`:ro`	Read-only mount

Run the example

mkdir -p ~/compose-demo/site && cd ~/compose-demo
printf '<h1>It works!</h1>\n' > site/index.html
# Save the YAML above as compose.yml
docker compose config --quiet
docker compose up -d
docker compose ps
curl -I http://127.0.0.1:8080

Stop it with docker compose down. For production, pin tested image versions or digests rather than blindly updating every container.

Run the example​

Run the example