nginx.conf

server {
  listen 80; listen [::]:80;
  server_name mangatsu.example.com;
  return 301 https://$server_name$request_uri;
}

server {
  listen 443 ssl http2; listen [::]:443 ssl http2;

  server_name mangatsu.example.com;

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

  location / {
    proxy_pass http://localhost:3003;
    proxy_http_version                 1.1;
    proxy_cache_bypass                 $http_upgrade;
    # Proxy headers
    proxy_set_header Upgrade           $http_upgrade;
    proxy_set_header Connection        $connection_upgrade;
    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 X-Forwarded-Host  $host;
    proxy_set_header X-Forwarded-Port  $server_port;
    # Proxy timeouts
    proxy_connect_timeout              60s;
    proxy_send_timeout                 60s;
    proxy_read_timeout                 60s;
  }

  # gzip
  gzip            on;
  gzip_vary       on;
  gzip_proxied    any;
  gzip_comp_level 6;
  gzip_types      text/plain text/css text/xml application/json application/javascript application/rss+xml application/atom+xml image/svg+xml;
}