nginx.conf

upstream app {
  server 'app:3000';
}

server {
  server_name _;
  listen 80 default_server;
  #listen [::]:80 ipv6only=on default_server;
  listen 443 ssl http2;
  #listen [::]:443 ipv6only=on ssl;

  ssl_protocols TLSv1.2 TLSv1.3;
  ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384;
  ssl_prefer_server_ciphers off;
  ssl_session_timeout 1d;
  ssl_session_cache shared:SSL:10m;  # about 40000 sessions
  ssl_session_tickets off;
  
  add_header Cache-Control                     "max-age=86400, private";
  # Decidim needs this for security forgery protection
  # add_header Referrer-Policy                   "no-referrer" always;
  add_header X-Content-Type-Options            "nosniff" always;
  add_header X-Download-Options                "noopen" always;
  add_header X-Frame-Options                   "SAMEORIGIN" always;
  add_header X-Permitted-Cross-Domain-Policies "none" always;
  add_header X-Robots-Tag                      "noindex,nofollow" always;
  add_header X-XSS-Protection                  "1; mode=block" always;

  ssl_certificate /etc/ssl/certs/ssl-bundle.pem;
  ssl_certificate_key /etc/ssl/certs/privatekeymultidominiogetxo.pem;

  # ~2 seconds is often enough for most folks to parse HTML/CSS and
  # retrieve needed images/icons/frames, connections are cheap in
  # nginx so increasing this is generally safe...
  keepalive_timeout 5;  # path for static files

  root /app/public;
  access_log /var/log/nginx/access.log;
  error_log /var/log/nginx/error.log;
  set $upstream http://app;

  location / {
    proxy_pass $upstream;
    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;

    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
    proxy_http_version 1.1;
  }
}