title: Google Cloud LB: Change "server error" default html page
body: <p>By default, if the load balance can't find a backend to redirect traffic to, for example if all available backends are down, it shows this html page:</p>
  
  <p><a href="https://i.stack.imgur.com/Md4J0.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Md4J0.png" alt="enter image description here"></a></p>
  
  <p>Transcript:</p>
  
  <blockquote>
    <h3>Error: Server Error</h3>
    
    <p>The server encountered a temporary error and could not complete your request.
    Please try again in 30 seconds.</p>
  </blockquote>
  
  <p>I would like to use my own static html page instead.<br>
  I saw this on the LB + Cloud storage page <a href="https://cloud.google.com/compute/docs/load-balancing/http/using-http-lb-with-cloud-storage" rel="noreferrer">here</a>:</p>
  
  <blockquote>
    <p>You can also configure a custom index page and a custom error page that will be served if the requested object doesn’t exist. This can be done by adding a Website Configuration to your Cloud Storage bucket. With a Website Configuration, you could serve a static webpage directly out of a Cloud Storage bucket from your own domain.</p>
  </blockquote>
  
  <p>How would that work ?
  I know how to host static page on cloud storage, but how would I use it with the LB ?</p>