lambda-restify

A restify/expressjs like interface for aws lambda with api gateway event.

Installation

npm install --save lambda-restify

What is it about

If you are writing aws lambda function to develop rest apis using aws api gateway, this package will help you with request/response/routing/middlewares/versioned apis type features generally found in packages like restify or express.

Instead of using http module for opening a server and listening for incoming requests, this package relies on lambda event and callback.

When you make an http request against aws apigateway it triggers aws lambda with an event containing all the information about the incoming request (like method, url, querystring, headers, and body). lambda-restify relies on that information to create request object.

When your route handler sends response back (including headers, content), lambda-restify triggers lambda callback.

Supported features

• Full support for restify request/response api
• Pre routing hooks
• Middlewares
• Routing
• Versioned apis

Dependency

It requires node >= 6.10.0. Make sure you choose "6.10.2" or above while creating lambda function. At the time of writing lambda supports v4.3.2 and 6.10.2.

Getting started

Install the package

npm install --save lambda-restify

Create server

See list of supported options here.

const Server = require('lambda-restify').default;
const server = new Server(options);

Or, if you are using imports

import Server from 'lambda-restify';
const server = new Server(options);

Attach your routes and middlewares

See restify documentation for documentation on server.pre, server.use, server.get (and other http verbs). Since lambda-restify uses restify like interface all that docs apply here as well.

server.pre(function(req, res, next) {
    // this handler is run for all routes, even 404
    
    // do something here
    next()
})

server.use(function(req, res, next) {
    // this handler is run for after routing is done 
    // and successful match is found (not on 404)

    // do something here
    next()
})

server.post('/user/:id', function(req, res) {
    
    // headers available 
    const apiKey = req.header('apikey');
    
    // route param
    const userId = req.params.id;
    
    // query string
    const queryValue = req.query('queryKey')

    // body
    const name = req.body.name

    // send response with res.json or res.send
    res.json({
        status: 1
    })
})

// define other route handlers

Attach lambda handler

exports.yourlambdaHandler = function(event, context, callback) {
    server.handleLambdaEvent(event, context, callback)
}

Documentation

Note Most likely, you will need to set:

context.callbackWaitsForEmptyEventLoop = false 

before calling server.handleLamdaEvent in your lamda handler. See http://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-context.html for details.

See restify documentation. Following items work just as they did in restify:

• Request:
  • headers
  • url
  • httpVersion
  • method
  • params
  • body
  • rawBody
  • header(name: string, defaultValue: string)
  • accepts(type: string | string[])
  • acceptsEncoding(type: string | string[])
  • getContentLength()
  • contentLength() [alias of getContentLength]
  • getContentType()
  • contentType() [alias of getContentType]
  • time()
  • date()
  • getQuery()
  • query() [alias of getQuery()]
  • getUrl()
  • href()
  • id(reqId?: string)
  • getId()
  • getPath()
  • path() [alias of getPath]
  • is(type: string)
  • isSecure()
  • isChunked()
  • toString()
  • userAgent()
  • version()
  • matchedVersion()
  • trailer(name: string, value?: string) [no trailers support. it just pass back the default value]
  • isKeepAlive()
  • isUpload()
• Response
  • finished
  • headersSent
  • sendDate
  • statusCode
  • statusMessage
  • serverName
  • cache(type?: any, options?: any)
  • noCache()
  • header(name: string, value?: any)
  • setHeader(name: string, value: any)
  • getHeaders()
  • headers() [alias of getHeaders]
  • send(code?: number, body?: string | json, headers?: json)
  • sendRaw(code?: number, body?: string | json, headers?: json)
  • removeHeader(name: string)
  • writeHead(code?, message?, headers?)
  • write(chunk: string | Buffer, encoding?: string, callback?: any)
  • end(data?: string | Buffer, encoding?: string, callback?)
  • get(name: string)
  • json(code?, body?, headers?)
  • link(l, rel)
  • charSet(type: string)
  • redirect(...)
  • status(code: number)
  • set(name: string | object, val?: string)
  • getHeaderNames()
  • hasHeader(name: string)
• Server
  • pre(handlers)
  • use(handlers)
  • get(path?, options?, handlers)
  • del(path?, options?, handlers)
  • head(path?, options?, handlers)
  • opts(path?, options?, handlers)
  • post(path?, options?, handlers)
  • put(path?, options?, handlers)
  • patch(path?, options?, handlers)
  • param(name, fn)
  • versionedUse(versions: string | string[], fn)

Server.handleLambdaEvent(lambdaEvent, context, lambdaCallback) Plug this into lambda handler to route all incoming lambda events.