Load balancer custom error page

To respond with customer error page and override default response with a custom one you can use Amazon API Gateway or Amazon CloudFront as this functionality is available out of the box.

https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-gatewayResponse-definition.html#supported-gateway-response-types

https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/GeneratingCustomErrorResponses.html

As for the using the Application load balancer, firstly need to understand your setup. I have attached here a diagram based off of my understanding of your current setup (2 versions) and possible solutions. Happy to discuss more.

Thank you for your answer. I have a conversation with the developers and we are decided to implement custom page 503 using S3 + CloudFront. In this case, I have an issue and ask you to help me.

So I have LoadBalancer dev-alb which is attached to Route53. Due to the Youtube tutorial, I created an S3 bucket and distributed CloudFront to this S3 bucket. Then I realized that something went wrong and changed my S3 bucket for another tutorial from re:Post Now my bucket has no public access and CloudFront has Origin Access.

I stopped 2 tasks BE and FE to see custom error 503, but unfortunately, I see the standard message. I'm confused because all tutorials have their own peculiarity.

I need:

• Using my LoadBalancer
• I stop BE and FE tasks
• User sees my custom error 503 (I uploaded it to my S3 yet)

Maybe I should distribute CloudFriont to my LoadBalancer instead S3?

Also, I re-check information from this suggestion. My consequence next:

1. Create non-public S3 bucket and add error503.html page
2. Create CloudFront distributed to ELB (origin path /*)
3. In the CF create an origin with S3 point (provide S3 Origin Access)
4. In the CF create a behavior of S3 (first priority)
5. Set up the Error page

But nothing happened, maybe I something missing?