Lambda Starter Kit 
to enable the latest JavaScript ES6 language features and simplification of code with the class syntaxWebpack to bundle only production dependencies to a single file, watch for changes and eliminate dead code
AWS Sam Local to emulate API Gateway locally so you can test your Lambda functions without deploying to AWS
Jest to test and confirm code works during development and before deploying to production
Installation
cd YourLambdaFunctionDirectory
git clone [email protected]:buildbreakdo/aws-api-lambda.git .
npm install
Create
To ensure correct assignment of IAM, role and permissions the recomendation is to initialize the lambda function manually on AWS.
- Create a Lambda Function using the AWS Console
- Update function-name in
package.jsonwith the name of the function you just created:
// package.json
...
"scripts": {
...
"update": "aws lambda update-function-code --function-name MyNewLambdaFunctionName --zip-file fileb://dist.zip --publish",
...
}
...
- Install
aws-cli npm run deployto build, run tests and update your function to the latest code
Run Scripts
Build
Use webpack to build/index.js:
npm run build
Deploy
Build, execute tests in continuous integration mode (bail on failure) and update your Lambda function with the latest code:
npm run deploy
Test
Run jest tests:
npm run test
Run jest tests in continuous integration mode (hard exit on test failure):
npm run test:ci
Run Jest tests continuously and watch for changes:
npm run test:watch
Debug Jest tests with Chrome browser:
- Insert
debuggeron a line in your test npm run test:debug- Open Chrome and navigate to about:inspect
Watch
Monitor src folder for changes and rebuild when changes occur.
npm run watch
Start
Used to be the case that we had to deploy a lambda function to test what would actually happen in a production environment. This is no longer the case, now we can emulate API Gateway and AWS Lambda locally using the AWS-SAM-CLI from Amazon. The template.yml file in the root of the repository is the configuration used by SAM Local (points to code in build/index.js).
Local Development Prerequisites. Running functions locally with SAM Local requires Docker to be installed and running.
- macOS: Docker for Mac
- Windows: Docker Toolbox
- Linux: Check your distro’s package manager (e.g. yum install docker)
npm install -g aws-sam-local
npm start
Starts the AWS SAM Local development server on http://127.0.0.1:3000. Open http://127.0.0.1:3000 in your browser to execute your Lambda function.
Note: You only need to restart SAM CLI if you update your AWS SAM template.
SAM Local will watch your build directory for changes and reload when changes
occur. Be sure to run npm run watch to monitor your src directory (where you will be writing code) to ensure SAM Local
always has the latest build/index.js. Happy coding!
License
MIT