First off: Yes I found this stackoverflow question already and I'm pretty sure I have done all the things described.
That said; I am currently in a situation where I try to get AWS api gateway up and running serving as a fornt-end to the batch jobs queue's. My final result would be something like making a post that would trigger the creation of a batch job in a specific queue.
I now have an REST API gateway setup with a userrole that is able to run batch jobs and also has full access to EC2 and api gateway. When I run a mock service and/or a dummy HTTP service all goes well. I get either my custom message or the mock message of status 200.
No matter what I try however I always get the same response (both in the UI as well as in Postman):
{
"message": "Forbidden"
}
I have the API key enabled as well as CORS. Furthermore I am not limiting this by means of waf and/or firewall ruling. It is directly connected to the internet. I have setup a usage plan which covers my tests as well.
I have isolated my problem to the interaction with the batch module. When I use a mock service on the same API I get no errors.
The very minimal situation I could come up with is asking for the job definitions or queues which I took from this link. This can be seen in this screenshot from the Integration Request tab:
Having done pretty much everything in the link at the top of this post I am out of options and/or ways to get this right.
What important thing am I missing?