sqs-forwarder

This project will help you out if you want to consume messages from SQS by an HTTP endpoint. The library will take configured amount of messages and send them to the specified url.

It can be nicely used in a lambda that is triggered by a timer. To test things out, there is a way how to run the service locally:

Running service locally

In order to run this service locally, you need to mock the AWS resources (SQS + SNS) and also the receiving HTTP server. Commands:

Install mock aws services

If you want to be able to emulate the run of the service locally, this docker container will give you SNS & SQS services

docker run -d --name goaws -p 4100:4100 pafortin/goaws

Install server that will console log everything

If you want to know locally, what is your service sending to the remote HTTP server, you can use this package, that will console log each request

npm install console-log-server --global

(Optional) If stopped, start the goaws again (for example you restarted the PC)

docker start goaws

Run the logging server

console-log-server --port 3000

Export the AWS_REGION to your environment

There is an annoying legacy dependency of some aws-sdk services on the AWS_REGION env variable. Make sure that before you run your service, this variable is set up (it is populated by AWS themselves in staging and prod)

export AWS_REGION=eu-west-1

Now you should have everything ready to invoke your function locally.

Usage

const sqsForwarderFactory = require('sqs-forwarder')
 
const sqsForwarder = sqsForwarderFactory({
  sqs: {
    url: "http://localhost:4100/queue/local-queue3",
  },
  http: {
    url: "http://localhost:3000"
  }
})
 
/**
* The process method takes as an argument an array of Decorators of the http request.
* The decorator is a function, that takes an axios (https://www.npmjs.com/package/axios) request, modifies it
* and returns a new request. In the beginning, the request contains  
* {
*   url: 'url provided in the factory',
*   method: 'defaults to POST',
*   data: 'message from SQS'
* }
* You can modify or add other parameters to the request.
* There are 3 decorators pre-packed 
* 
* snsMessageParser - strips SNS envelope from the message
* basicContentType - guesses content type (json, text)
* auth0authenticate - adds Authorization header using Auth0
*/
sqsForwarder.process([sqsForwarder.snsMessageParserDecorator, sqsForwarder.basicContentTypeDecorator])
 

In the beginning, this will probably process 0 messages, since the queue is empty. In order to see something, you should push a message to the SNS. Easiest way how to do that is importing the swagger file for the SNS endpoint from this URL https://www.getpostman.com/collections/091386eae8c70588348e You can set the {{URL}} variable to localhost:4100 so you don't have to fill anything.

After you have the collection, locate the Publish endpoint, and change the TopicArn to arn:aws:sns:local:000000000000:local-topic1. This will publish the message to http://localhost:4100/queue/local-queue3 which is set up for dev to be consumed.