Docker Networking: O Guia Definitivo 🌐

╔════════════════════════════════════════════╗
║           DOCKER NETWORK TOPOLOGY          ║
║                                           ║
║    [Container A] ←→ [Bridge] ←→ [Host]    ║
║         ↑             ↑          ↑        ║
║    [Container B] [Overlay] [MacVLAN]      ║
║                                           ║
╚════════════════════════════════════════════╝

Network Drivers 🚗

Bridge Network (Default)

# Criar rede bridge
docker network create --driver bridge minha-rede

# Conectar container
docker run -d --network minha-rede nginx

# Inspecionar rede
docker network inspect bridge

Host Network

# Usar rede do host
docker run --network host nginx

# Verificar portas
netstat -tulpn

None Network

# Sem rede
docker run --network none alpine

Overlay Network

# Criar rede overlay
docker network create \
  --driver overlay \
  --attachable \
  --subnet=10.0.9.0/24 \
  overlay-net

# Habilitar criptografia
docker network create \
  --driver overlay \
  --opt encrypted \
  secure-overlay

Macvlan

# Criar rede macvlan
docker network create \
  -d macvlan \
  --subnet=192.168.1.0/24 \
  --gateway=192.168.1.1 \
  -o parent=eth0 \
  macvlan-net

Network Configuration 🔧

Port Mapping

# Mapear porta única
docker run -p 8080:80 nginx

# Múltiplas portas
docker run \
  -p 80:80 \
  -p 443:443 \
  nginx

# UDP ports
docker run -p 53:53/udp dns-server

# Range de portas
docker run -p 8000-8010:8000-8010 app

DNS Configuration

# Configurar DNS
docker run --dns 8.8.8.8 nginx

# Arquivo de configuração
cat /etc/docker/daemon.json
{
  "dns": ["8.8.8.8", "8.8.4.4"],
  "dns-search": ["example.com"]
}

Network Security 🔒

Network Policies

# Network policy básica
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: default-deny
spec:
  podSelector: {}
  policyTypes:
  - Ingress
  - Egress

Firewall Rules

# Regras iptables
iptables -I DOCKER-USER -i ext_if ! \
  -s 192.168.1.0/24 -j DROP

# Permitir portas específicas
iptables -A DOCKER-USER -p tcp \
  --dport 80 -j ACCEPT

Network Troubleshooting 🔍

Debug Commands

# Inspecionar rede
docker network inspect bridge

# Listar endpoints
docker network inspect -f \
  '{{range .Containers}}{{.Name}} {{.IPv4Address}}{{end}}' \
  bridge

# Estatísticas
docker stats --format \
  "table {{.Container}}\t{{.NetIO}}"

Network Tools

# tcpdump
docker run --net=container:target \
  nicolaka/netshoot \
  tcpdump -i any port 80

# netstat
docker exec container netstat -tulpn

# ping test
docker run --rm busybox ping container_name

Docker Compose Networking 📦

Basic Configuration

version: '3.8'
services:
  web:
    networks:
      - frontend
      - backend
  api:
    networks:
      backend:
        ipv4_address: 172.16.238.10

networks:
  frontend:
    driver: bridge
  backend:
    driver: bridge
    internal: true

Advanced Features

networks:
  overlay_net:
    driver: overlay
    driver_opts:
      encrypted: "true"
    ipam:
      driver: default
      config:
        - subnet: 10.0.9.0/24

Network Monitoring 📊

Basic Monitoring

# Network stats
docker stats --format \
  "table {{.Name}}\t{{.NetIO}}"

# Network events
docker events --filter 'type=network'

# Container connections
docker exec container ss -tulpn

Advanced Monitoring

# Detailed metrics
docker run --rm \
  --net=container:target \
  nicolaka/netshoot \
  iftop

# Network profiling
docker run --rm \
  --net=container:target \
  nicolaka/netshoot \
  nethogs

Best Practices 💡

Network Design

Use user-defined networks
Isolate sensitive services
Implement network policies
Monitor network traffic
Regular security audits

Performance Tips

Use host network when possible
Minimize network overhead
Optimize DNS resolution
Use appropriate drivers
Monitor bandwidth usage

Learn Docker Help

Docker Networking: O Guia Definitivo 🌐

Network Drivers 🚗

Bridge Network (Default)

Host Network

None Network

Overlay Network

Macvlan

Network Configuration 🔧

Port Mapping

DNS Configuration

Network Security 🔒

Network Policies

Firewall Rules

Network Troubleshooting 🔍

Debug Commands

Network Tools

Docker Compose Networking 📦

Basic Configuration

Advanced Features

Network Monitoring 📊

Basic Monitoring

Advanced Monitoring

Best Practices 💡

Network Design

Performance Tips

Waifu Network Tips 🎀

Próximos Passos 🎯

Referências 📚