Be able to serve a static page custom page on timeout

[allan-simon]

AWS ALB's can be used as a frontend load balancer for lambda,

BUT they have a drawbacks which is that they don't have the possibility to customize 502 error page

As Bref has a little extra window , would it make sense to be able to configure it to return its own "timeout" response, so that users don't see a blank page with just written "502" ?

[mnapoli]

Oh, that's an interesting idea, but then we would loose the invocation being reported as an error:

bref/src/Event/Http/FpmHandler.php

Lines 147 to 151 in bdf8331

	// Throw an exception so that:
	// - this is reported as a Lambda execution error ("error rate" metrics are accurate)
	// - the CloudWatch logs correctly reflect that an execution error occurred
	// - the 500 response is the same as if an exception happened in Bref
	throw new Timeout($timeoutDelayInMs, $context->getAwsRequestId());

With API Gateway we can customize the responses to achieve that, but yeah, with ALB you seem to be out of luck :/
I'm not sure we want to an such an option just for ALB, especially since that option goes against the Lambda behavior (mark the invocation as failed via an error = no response).

[allan-simon]

hmmm maybe I need to reconsider why I choose ALB instead of API Gateway

https://dashbird.io/blog/aws-api-gateway-vs-application-load-balancer/

I may have mistakenly think "ALB is less capable than API Gateway, so it will be less expensive"

[dhrrgn]

A little late here, but you could put a CloudFront distribution in front of your ALB and add a custom error page for 502/504 statuses to that origin.