Issue with setting multiple headers

[andybee]

Setting up the layer on a Lambda function requested through ALB seems to only return the first header set within the PHP logic.

<?php
$host = '.' . str_replace('www.', '', $_SERVER['HTTP_HOST']);
setcookie('basketId', '123', time() + 2592000, '/', $host, false, false);
setcookie('basketKey', '456', time() + 2592000, '/', $host, false, false);
echo 'Hello';

Returns:

HTTP/1.1 200 OK
Connection: keep-alive
Content-Length: 5
Content-Type: text/html; charset=UTF-8
Date: Thu, 05 May 2022 11:52:43 GMT
Server: awselb/2.0
Set-Cookie: basketId=123; expires=Sat, 04-Jun-2022 11:52:43 GMT; Max-Age=2592000; path=/; domain=.phptestalb-807238318.eu-west-2.elb.amazonaws.com

Hello

[andybee]

This was due to an ALB listener configuration issue.

The bootstrap within the layer correctly respects whether the incoming request contains multiValueHeaders or not. If not, it can only return a single value per header and uses the first in the response from the executed PHP script.

In the AWS Console, in the EC2 application, under 'Load Balancing' select 'Target Groups'. Click the target group that calls the Lambda function, then go to attributes. Enable 'multi value headers'.