Document how to use SQS to trigger Lambda

[mnapoli]

This topic has been brought up multiple times and I realized that we have no "official" issue for this.

Here is a good article that will help cover the details in the documentation article to create: https://lumigo.io/blog/sqs-and-lambda-the-missing-guide-on-failure-modes/

[victormacko]

This might help; https://docs.aws.amazon.com/lambda/latest/dg/with-sqs.html
I've done it with Symfony and it's pretty straight-forward ... is anyone working on this page already, or do you need a hand with it?

[mnapoli]

@victormacko I'm working on integrating Symfony Messenger. I'm interested, did you use Messenger or no library?

[victormacko]

Yes, i've used messenger, with the following packages to get SNS happening;

• enqueue/sns
• sroze/messenger-enqueue-transport
  (can't remember if there's anything different needed for SQS ... prob just a different pkg if anything)

The changes between SNS and SQS are pretty minimal for receiving messages -- just the 'bin/consume' handler needs to be able to adjusted for the different JSON structure.

There's a good article on it here which I followed; http://developer.happyr.com/symfony-messenger-on-aws-lambda

I think in theory you could get away with the extra packages if you only wanted lambda to 'receive' SQS/SNS rather than using $messenger->dispatch to add back to SNS/SQS.

In terms of hooking lambda to SQS, you just need to give the lambda function some extra permissions, and setup the trigger on the SQS queue ... there's more details here which i've followed for SQS;
https://docs.aws.amazon.com/lambda/latest/dg/with-sqs.html

It's worth mentioning that setting up a dead-letter-queue is a good idea too -- if the lambda PHP fn throws and error, the queue will automatically re-try sending it to lambda until you remove the trigger... a friend's already gotten a nasty surprise in the form of a big bill $$ from that mistake!

[mnapoli]

I've improved the documentation in 1.0 with a short example. There's also https://serverless-visually-explained.com/ that includes more complete examples.