Proxy Reverso

Configure proxies reversos para rotear tráfego, encerrar TLS, impor limites de taxa e servir como gateway entre clientes e serviços de backend.

Quando Usar

• Roteamento de tráfego de um domínio público para um ou mais serviços de backend.
• Encerrar TLS na borda e encaminhar HTTP simples para os backends.
• Adicionar limitação de taxa, CORS, cabeçalhos de segurança e controle de acesso.
• Consolidar múltiplos serviços sob um único domínio com roteamento baseado em caminho.
• Lidar com atualizações WebSocket, proxy gRPC ou passagem HTTP/2.

Pré-requisitos

• Serviço(s) de backend rodando em host:porta conhecidos.
• Certificado TLS (Let's Encrypt, ACM ou autoassinado para desenvolvimento).
• nginx 1.25+ ou Traefik 3.x instalado.
• Registro DNS apontando o domínio para o servidor proxy.

Proxy Reverso com nginx

Proxy HTTPS Básico com Redirecionamento

# /etc/nginx/sites-available/app.example.com
server {
    listen 80;
    server_name app.example.com;
    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl http2;
    server_name app.example.com;

    # TLS configuration
    ssl_certificate     /etc/letsencrypt/live/app.example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/app.example.com/privkey.pem;
    ssl_protocols       TLSv1.2 TLSv1.3;
    ssl_ciphers         ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384;
    ssl_prefer_server_ciphers on;
    ssl_session_cache   shared:SSL:10m;
    ssl_session_timeout 10m;

    # Security headers
    add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" always;
    add_header X-Frame-Options DENY always;
    add_header X-Content-Type-Options nosniff always;
    add_header Referrer-Policy strict-origin-when-cross-origin always;

    # Proxy to backend
    location / {
        proxy_pass http://127.0.0.1:3000;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;

        # Timeouts
        proxy_connect_timeout 5s;
        proxy_read_timeout 60s;
        proxy_send_timeout 60s;

        # Buffering
        proxy_buffering on;
        proxy_buffer_size 4k;
        proxy_buffers 8 4k;
    }
}

Roteamento Baseado em Caminho para Múltiplos Serviços

server {
    listen 443 ssl http2;
    server_name app.example.com;

    ssl_certificate     /etc/letsencrypt/live/app.example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/app.example.com/privkey.pem;

    # Frontend SPA
    location / {
        proxy_pass http://127.0.0.1:3000;
        proxy_set_header Host $host;
    }

    # API backend
    location /api/ {
        proxy_pass http://127.0.0.1:8080/;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_read_timeout 120s;
    }

    # WebSocket endpoint
    location /ws/ {
        proxy_pass http://127.0.0.1:8080;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
        proxy_read_timeout 86400s;  # 24h for long-lived connections
    }

    # Static assets with caching
    location /static/ {
        alias /var/www/static/;
        expires 30d;
        add_header Cache-Control "public, immutable";
    }
}

Limitação de Taxa

# Define rate limit zones in http block
http {
    # 10 requests/second per IP
    limit_req_zone $binary_remote_addr zone=api_limit:10m rate=10r/s;

    # 1 request/second for login
    limit_req_zone $binary_remote_addr zone=login_limit:10m rate=1r/s;

    # Connection limit per IP
    limit_conn_zone $binary_remote_addr zone=conn_limit:10m;
}

server {
    listen 443 ssl http2;
    server_name app.example.com;

    # Apply rate limit to API
    location /api/ {
        limit_req zone=api_limit burst=20 nodelay;
        limit_req_status 429;
        proxy_pass http://127.0.0.1:8080;
    }

    # Strict rate limit on auth endpoints
    location /api/auth/ {
        limit_req zone=login_limit burst=5;
        limit_req_status 429;
        proxy_pass http://127.0.0.1:8080;
    }

    # Connection limit
    location / {
        limit_conn conn_limit 100;
        proxy_pass http://127.0.0.1:3000;
    }
}

Compressão Gzip e Brotli

http {
    gzip on;

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