tareq89/local-kinesis-lambda-runner

A script for local development of lambda functions that listen to kinesis streams

local-kinesis-lambda-runner

The Rabble Rouser project makes extensive use of kinesis streams, and also uses lambda functions to process events from the stream. We want a way to spin up a whole Rabble Rouser instance locally, and this package is part of the solution to that problem.

This is a script that will poll a kinesis stream forever, and invoke your lambda function whenever a new event is detected.

Also if someone can come up with a better name, please do.

Usage

First install the package as a development dependency:

npm install --save-dev @rabblerouser/local-kinesis-lambda-runner

Then add a script to your project that looks something like this:

const run = require('@rabblerouser/local-kinesis-lambda-runner');
const lambda = require('./index').handler;

run(lambda);

You might also like to add an npm task to run that script:

{
  "scripts": {
    "start": "node localDev.js"
  }
}

Running it

If you follow the setup above, you can start up your lambda locally with npm start, although it won't work properly without a little configuration:

• KINESIS_ENDPOINT: The endpoint where kinesis is located
• STREAM_NAME: The name of the stream to poll

E.g:

KINESIS_ENDPOINT="http://kinesis:4567" STREAM_NAME="rabblerouser_stream" npm start

Note that this is only intended for local development with something like kinesalite, so the AWS region and credentials are internally hardcoded to arbitrary values. This script could be extended to support running against a real kinesis stream, it would just be a matter of parameterising the extra config.

For a full example of this script in action, see the docker-compose config for rabblerouser/core.

Publishing this library

Scoped packages (which this is) are private by default on npm, which is a paid feature. To publish publically, use this command:

npm publish --access=public