Node AWS Lambda API Gateway

A tiny AWS Node helper for API Gateway Lambda proxies.

Useful for handling gateway parameters (both query and body), require parameters, setting default values and responses.

Install

Using npm:

npm install node-aws-lambda-ag --save

Usage

var AG = require('node-aws-lambda-ag')

// Using ES6 syntax 
// import AG from 'node-aws-lambda-ag'

// Define expected API Gateway parameters
const PARAMS = [
  {
    name: 'category',
    required: true,
    default: 'none'
  },
  {
    name: 'offset',
    required: false,
    default: 0
  },
  {
    name: 'limit',
    required: false,
    default: 15
  }
]

export const main = (event, context, callback) => {
  // Initialize the helper with predefined parameters
  let ag = new AG(event, PARAMS, callback)

  // Fetch parameters
  console.log('Got param: ', ag.param('category'))

  // Send failed response
  if (ag.param('limit') > 100)
    ag.failure({ error: 'Limit overflow' })

  // Send successful response
  else
    ag.success({ status: 'ok' })
}

If a callback method is provided and a required parameter is absent in the event object, a failed response will automatically be issued.

API

Constructor

constructor(event, params, callback = null)

• event (object) - the AWS Lambda event.
• params (array) - your predefined parameters.
• callback (function, optional) - the callback function used by responses.

Retrieveing a parameter

AG.param(name)

• name (string) - the name of the param to retrieve. If the param was not provided in the request a predefined default value will be returned. If no default value is defined, or the param is non-existing, null will be returned.

Sending a success response

AG.success(response)

• response (object) - send a status 200 response with the provided object.

Sending a failed response

AG.failure(response, statusCode = 500)

• response (object) - send a status 500 response with the provided object.
• statusCode (number, optional) - specify the HTTP status code.