Créer un fichier .conf, par exemple /etc/nginx/conf.d/myapp.conf :

server {
  listen 80;
  listen [::]:80;

  server_name example.com;

  location / {
      proxy_pass http://localhost:3000/;
  }
}

Tester la configuration:

$ sudo nginx -t

Reload

$ sudo nginx -s reload

sudo ufw allow 'Nginx HTTP'

Exemple:

server {
  listen 443 ssl;
  server_name vault.YOURDOMAIN.COM;

  ssl_certificate YOUR_SSL_CERTIFICATE.crt;
  ssl_certificate_key YOUR_SSL_CERTIFICATE_KEY.key;

  location / {
    proxy_pass http://127.0.0.1:8200;
    proxy_set_header Host $host;
    expires -1;
  }

  #ssl config per https://raymii.org/s/tutorials/Strong_SSL_Security_On_nginx.html
  ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

  ssl_ciphers "EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA256:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EDH+aRSA+AESGCM:EDH+aRSA+SHA256:EDH+aRSA:EECDH:!aNULL:!eNULL:!MEDIUM:!LOW:!3DES:!MD5:!EXP:!PSK:!SRP:!DSS:!RC4:!SEED";
  ssl_prefer_server_ciphers on;

  ssl_dhparam dhparam.pem;

  #only supported since 1.3.7
  ssl_stapling on;
  ssl_stapling_verify on;

  # Optimize SSL by caching session parameters for 10 minutes. This cuts down on the number of expensive SSL handshakes.
  # The handshake is the most CPU-intensive operation, and by default it is re-negotiated on every new/parallel connection.
  # By enabling a cache (of type "shared between all Nginx workers"), we tell the client to re-use the already negotiated state.
  # Further optimization can be achieved by raising keepalive_timeout, but that shouldn't be done unless you serve primarily HTTPS.
  ssl_session_cache    shared:SSL:10m; # a 1mb cache can hold about 4000 sessions, so we can hold 40000 sessions
  ssl_session_timeout  10m;

  add_header Strict-Transport-Security max-age=63072000;
  add_header X-Frame-Options DENY;
  add_header X-Content-Type-Options nosniff;
}