example.nginx.conf

server {
    server_name example.com;
    set $app 'example';

    listen 443 ssl;

    ssl_certificate      /etc/nginx/ssl/example.com.crt;
    ssl_certificate_key  /etc/nginx/ssl/example.com.key;

    root /srv/apps/$app/current/public;

    try_files $uri @passenger;

    # Maintenance

    error_page 503 @503;

    if (-f /srv/apps/$app/shared/system/maintenance.html) {
      return 503;
    }

    location @503 {
      # Serve static assets if found.
      if (-f $request_filename) {
        break;
      }

      # Set root to the public directory.
      root /srv/apps/$app/current/public;
      rewrite ^(.*)$ /system/maintenance.html break;
    }

    # Assets

    location ~ ^/(assets)/ {
      gzip_static on;
      expires max;
      add_header Cache-Control public;
    }

    # Backend server

    location @passenger {
      proxy_pass http://unix:/srv/apps/$app/passenger/app.sock:;
      proxy_set_header X-Forwarded-Proto $scheme;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header X-Forwarded-Host $host;
    }

}