Nginx Proxy for Maintenance Page hosted on S3

nginx-s3.conf

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

  # SSL Optional
  listen 443 ssl default_server;
  listen [::]:443 ssl default_server;
  ssl_certificate /etc/ssl/my_cert.pem;
  ssl_certificate_key /etc/ssl/my_cert.key;
  
  root /var/www/html;
  # Add index.php to the list if you are using PHP
  index index.html index.htm index.nginx-debian.html;

  server_name _;

  resolver 8.8.8.8;

  proxy_intercept_errors on;
  error_page 403 404 500 502 503 @s3error;
  proxy_set_header Authorization "";

  # Capture asset requests
  location ~ .*/maintenance-page-files/(.*)$ {
    proxy_pass http://my-bucket.s3.amazonaws.com/maintenance-page-files/$1;
  }

  # Capture all requests
  location / {
    set $indexfile         "my-bucket.s3.amazonaws.com/maintenance-page.html";
    proxy_pass             http://$indexfile;
  }

  # Redirect to Nginx error page instead of S3 error page
  location @s3error {
    internal;
  }
}