nginx maintenance page

#Server block to accept server ip address
#Server block to accept www
#Server block to redirect http to https
# Main Server block to virtual host
server {
  listen       443 ssl;
  listen       [::]:443 ssl;
  server_name  my_site;
  ssl_certificate /etc/letsencrypt/live/my_site/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/my_site/privkey.pem;
  ssl_trusted_certificate /etc/letsencrypt/live/my_site/chain.pem;

  root /srv/my-site/public;
  index index.html;
  error_page 502 /502.html;
  location / {
    if ($remote_addr != "my.ip.goes.here") {
      return 503;
    }
    error_page 503 @maintenance;
    location @maintenance {
      rewrite ^(.*)$ /error503.html break;
    }
    try_files $uri @proxy;
  }
  location @proxy {
      proxy_redirect off;
      proxy_http_version 1.1;
      proxy_set_header Upgrade $http_upgrade;
      proxy_set_header Connection $connection_upgrade;
      proxy_set_header Proxy '';
      proxy_set_header Host $http_host;
      proxy_set_header X-Forwarded-Proto $scheme;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header X-Real-IP $remote_addr;

      set $backend http://127.0.0.1:8000;
      proxy_pass $backend;
   }