Hey there. We are currently using Caddy2 as a reverse proxy to a Tomcat based application; which also travels through an AWS ALB. We have occasions when the tomcat application becomes overload and stops responding and the AWS ALB starts showing a 503 error. From what I have found the AWS ALB responses cannot be customized but it appears if I leverage Caddy I could maybe redirect the error to a static page on the caddy side?
This is more theory crafting at this point. So does anyone have experience with AWS ALB with Caddy acting as a reverse proxy and providing custom error pages?
Yes it’s possible with the handle_response subdirective of reverse_proxy, but there’s currently a bug that prevents it from working correctly so you’ll need to wait until the next release when it gets fixed.