Serverless - AWS Node.js Typescript

This project has been generated using the aws-nodejs-typescript template from the Serverless framework.

For detailed instructions, please refer to the documentation.

Some personal modifications are:

• Git hooks with Husky, running ESLint, Prettier and Tests on every commit.
• Created a directory for Architecture Decision Records, as described by Michael Nygard.
• Open API documentation with redoc-cli.
• Canary Deployments with serverless-plugin-canary-deployments.
• CloudWatch Alerts with serverless-plugin-aws-alerts.
• Prune of Old Lambda Versions with serverless-prune-plugin.

Installation/deployment instructions

• Run yarn to install the project dependencies
• Run yarn sls deploy to deploy this stack to AWS

Test your service

This template contains a single lambda function triggered by an HTTP request made on the provisioned API Gateway REST API /hello route with POST method. The request body must be provided as application/json. The body structure is tested by API Gateway against src/functions/hello/schema.ts JSON-Schema definition: it must contain the name property.

• requesting any other path than /hello with any other method than POST will result in API Gateway returning a 403 HTTP error code
• sending a POST request to /hello with a payload not containing a string property named name will result in API Gateway returning a 400 HTTP error code
• sending a POST request to /hello with a payload containing a string property named name will result in API Gateway returning a 200 HTTP status code with a message saluting the provided name and the detailed event processed by the lambda

⚠️ As is, this template, once deployed, opens a public endpoint within your AWS account resources. Anybody with the URL can actively execute the API Gateway endpoint and the corresponding lambda. You should protect this endpoint with the authentication method of your choice.

Locally

In order to test the hello function locally, run the following command:

• yarn sls invoke local -f hello --path src/functions/hello/mock.json

Check the sls invoke local command documentation for more information.

Remotely

Copy and replace your url - found in Serverless deploy command output - and name parameter in the following curl command in your terminal or in Postman to test your newly deployed application.

curl --location --request POST 'https://myApiEndpoint/dev/hello' \
--header 'Content-Type: application/json' \
--data-raw '{
    "name": "Frederic"
}'

Template features

Project structure

The project code base is mainly located within the src folder. This folder is divided in:

• functions - containing code base and configuration for your lambda functions
• libs - containing shared code base between your lambdas

.
├── src
│   ├── functions            # Lambda configuration and source code folder
│   │   ├── hello
│   │   │   ├── handler.ts   # `Hello` lambda source code
│   │   │   ├── index.ts     # `Hello` lambda Serverless configuration
│   │   │   ├── mock.json    # `Hello` lambda input parameter, if any, for local invocation
│   │   │   └── schema.ts    # `Hello` lambda input event JSON-Schema
│   │   │
│   │   └── index.ts         # Import/export of all lambda configurations
│   │
│   └── libs                 # Lambda shared code
│       └── apiGateway.ts    # API Gateway specific helpers
│
├── package.json
├── serverless.ts            # Serverless service file
├── tsconfig.json            # Typescript compiler configuration
└── webpack.config.js        # Webpack configuration

3rd party librairies

• json-schema-to-ts - uses JSON-Schema definitions used by API Gateway for HTTP request validation to statically generate TypeScript types in your lambda's handler code base
• middy - middleware engine for Node.Js lambda. This template uses http-json-body-parser to convert API Gateway event.body property, originally passed as a stringified JSON, to its corresponding parsed object
• @serverless/typescript - provides up-to-date TypeScript definitions for your serverless.ts service file
• redoc-cli - provides a tool to configure and write our documentation using OpenAPI Specification.
• serverless-prune-plugin - prunes old lambda versions.
• serverless-plugin-aws-alerts - creates alerts automatically in CloudWatch.
• serverless-plugin-canary-deployments - implement canary deployments of Lambda functions with AWS CodeDeploy.