# Criar rede com sub-rede personalizada
docker network create \
  --driver bridge \
  --subnet 172.28.0.0/16 \
  --gateway 172.28.0.1 \
  my_network

# Executar container na rede
docker run -d --name app \
  --network my_network \
  nginx:alpine

services:
  frontend:
    image: nginx:alpine
    networks:
      - network_swarm_public
    ports:
      - "80:80"

  backend:
    image: node:20-alpine
    networks:
      - network_swarm_public
      - private
    expose:
      - "3000"

  database:
    image: postgres:16-alpine
    networks:
      - private  # Apenas interna

networks:
  network_swarm_public:
    external: true  # Rede pública compartilhada no Swarm
  private:
    driver: overlay
    internal: true  # Sem acesso externo

# Containers podem alcançar uns aos outros pelo nome do serviço
services:
  app:
    image: myapp
    networks:
      - network_swarm_public
    environment:
      # Use o nome do serviço como hostname
      DATABASE_HOST: database
      CACHE_HOST: redis

  database:
    image: postgres:16-alpine
    networks:
      - network_swarm_public

  redis:
    image: redis:alpine
    networks:
      - network_swarm_public

# Criar a rede pública do Swarm (Overlay)
docker network create \
  --driver overlay \
  --attachable \
  --opt encrypted \
  network_swarm_public

# Mapear host:container
docker run -p 8080:80 nginx

# Vincular a uma interface específica
docker run -p 127.0.0.1:8080:80 nginx

# Porta do host aleatória
docker run -P nginx

# Porta UDP
docker run -p 53:53/udp dnsserver

# Listar redes
docker network ls

# Inspecionar rede
docker network inspect my_network

# Testar conectividade
docker exec app ping -c 3 database

# Verificar DNS
docker exec app nslookup backend

# Visualizar mapeamentos de porta
docker port nome_do_container

# Entrar no namespace de rede do container
docker exec -it app sh

# Verificar resolução de DNS
cat /etc/resolv.conf
nslookup database

# Verificar conectividade
ping -c 3 backend
curl http://backend:3000/health