Get SQS URL from within Serverless function?

Question

I'm building a Serverless app that defines an SQS queue in the resources as follows:

resources:
  Resources:
    TheQueue:
      Type: "AWS:SQS:Queue"
      Properties:
        QueueName: "TheQueue"

I want to send messages to this queue from within one of the functions. How can I access the URL from within the function? I want to place it here:

const params = {
    MessageBody: 'message body here',
    QueueUrl: 'WHATS_THE_URL_HERE',
    DelaySeconds: 5
};

Answer 1

This is a great question!

I like to set the queue URL as an ENV var for my app!

So you've named the queue TheQueue.

Simply add this snippet to your serverless.yml file:

provider:
  name: aws
  runtime: <YOUR RUNTIME>
  environment:
    THE_QUEUE_URL: { Ref: TheQueue }

Serverless will automatically grab the queue URL from your CloudFormation and inject it into your ENV.

Then you can access the param as:

const params = {
    MessageBody: 'message body here',
    QueueUrl: process.env.THE_QUEUE_URL,
    DelaySeconds: 5
};

Answer 2

I go a bit of a different route. I, personally, don't like storing information in environment variables when using lambda, though I really like Aaron Stuyvenberg solution. Therefore, I store information like this is AWS SSM Parameter store.

Then in my code I just call for it when needed. Forgive my JS it has been a while since I did it. I mostly do python

var ssm = new AWS.SSM();
const myHandler = (event, context) => {
    var { Value } = await ssm.getParameter({Name: 'some.name.of.parameter'}).promise()

    const params = {
        MessageBody: 'message body here',
        QueueUrl: Value,
        DelaySeconds: 5
    };
}

There is probably some deconstruction of the returned data structure I got wrong, but this is roughly what I do. In python I wrote a library that does all of this with one line.