Nodejs-Typescript Serverless Example

The goal of the sample is to mock out the experience for writing serverless nodejs lambdas with typescript and being able to invoke them locally before deploying to AWS Lambda service. This project leverages the lambda-local package over alternatives like aws-serverless-runtime-emulator, lambda-docker, or serverless-offline which though robust, are a bit of an overkill and require quite the boilerplate if you particularly want to write vanilla lambdas using the aws-sdk

Getting started

You need nodejs, typescript and npm installed globally on your machine

1. clone this repository
2. Install the dependencies using npm install
3. Invoke the example lambda by running npm run invoke

Run in watch mode

The run the lambda in watch mode, there are various strategies that could be employed, either with nodemon or tsc compile watch. This repository currently uses none of the approaches, but you can create a http server instance of your lambda by running npm run dev:watch to listen on http://localhost:4000

N/B Ensure that Content-Type is set to application/json when using dev:watch mode

Example Request Payload (e.g, on postman)

 { 
     "event": {
     "path": "/test/hello",
     "headers": {
       "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
       "Accept-Encoding": "gzip, deflate, lzma, sdch, br",
       "Accept-Language": "en-US,en;q=0.8",
       "CloudFront-Forwarded-Proto": "https",
       "CloudFront-Is-Desktop-Viewer": "true",
       "CloudFront-Is-Mobile-Viewer": "false",
       "CloudFront-Is-SmartTV-Viewer": "false",
       "CloudFront-Is-Tablet-Viewer": "false",
       "CloudFront-Viewer-Country": "US",
       "Host": "wt6mne2s9k.execute-api.us-west-2.amazonaws.com",
       "Upgrade-Insecure-Requests": "1",
       "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.82 Safari/537.36 OPR/39.0.2256.48",
       "Via": "1.1 fb7cca60f0ecd82ce07790c9c5eef16c.cloudfront.net (CloudFront)",
       "X-Amz-Cf-Id": "nBsWBOrSHMgnaROZJK1wGCZ9PcRcSpq_oSXZNQwQ10OTZL4cimZo3g==",
       "X-Forwarded-For": "192.168.100.1, 192.168.1.1",
       "X-Forwarded-Port": "443",
       "X-Forwarded-Proto": "https"
     },
     "pathParameters": {
       "proxy": "hello"
     },
     "requestContext": {
       "accountId": "123456789012",
       "resourceId": "us4z18",
       "stage": "test",
       "requestId": "41b45ea3-70b5-11e6-b7bd-69b5aaebc7d9",
       "identity": {
         "cognitoIdentityPoolId": "",
         "accountId": "",
         "cognitoIdentityId": "",
         "caller": "",
         "apiKey": "",
         "sourceIp": "192.168.100.1",
         "cognitoAuthenticationType": "",
         "cognitoAuthenticationProvider": "",
         "userArn": "",
         "userAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.82 Safari/537.36 OPR/39.0.2256.48",
         "user": ""
       },
       "resourcePath": "/{proxy+}",
       "httpMethod": "GET",
       "apiId": "wt6mne2s9k"
     },
     "resource": "/{proxy+}",
     "httpMethod": "GET",
     "queryStringParameters": {
       "name": "me"
     },
     "stageVariables": {
       "stageVarName": "stageVarValue"
     }
   }
}