Serverless Node.js Application Deployment with AWS Lambda

This repository contains a Serverless Framework configuration for deploying a Node.js application on AWS Lambda, utilizing TypeScript and integrating with AWS services.

Prerequisites

Node.js (>= 14.x)
npm or yarn
AWS CLI configured with appropriate permissions
Serverless Framework installed globally (npm install -g serverless)

Project Structure

├── src
│   ├── handlers
│   │   └── lambda.ts
│   └── app.ts
├── .gitignore
├── package.json
├── serverless.yml
├── tsconfig.json
└── README.md

Setup

Install Dependencies:
```
npm install
```
Compile TypeScript:
```
npm run build
```
Environment Variables: Create a .env file in the root of your project with the following required variables:
```
MONGO_URI=your_mongodb_uri_here
```
Replace your_mongodb_uri_here with your MongoDB connection URI.
Deploy to AWS:
```
serverless deploy
```

Running Locally

To run your Serverless application locally, follow these steps:

Start Local Serverless Environment:
```
npm run offline
```
This command starts a local Serverless environment using the serverless offline plugin. It emulates AWS Lambda and API Gateway locally, allowing you to test your application without deploying it to AWS.
Access Your Local Application: Open your browser or use tools like curl to access endpoints defined in your serverless.yml, typically at http://localhost:3000 if using default settings.
Testing Endpoints: Use HTTP clients like curl or tools like Postman to test your API endpoints locally. For example:
```
curl http://localhost:3000/
```
Adjust the endpoint URL (http://localhost:3000/) based on your defined routes in serverless.yml.

Serverless Configuration

`serverless.yml`

org: dedeard
service: demo

provider:
  name: aws
  runtime: nodejs20.x

functions:
  api:
    handler: dist/lambda.handler
    events:
      - httpApi: '*' # or use 'http' for REST API Gateway
    layers:
      - arn:aws:lambda:us-east-1:730335295088:layer:common:2 # Example layer ARN

plugins:
  - serverless-dotenv-plugin
  - serverless-offline

build:
  esbuild:
    bundle: true
    external:
      - '@aws-sdk/*'
      - 'sharp'
    exclude:
      - '@aws-sdk/*'
      - 'sharp'
    packages: external

Scripts in `package.json`

The following scripts are available for linting, formatting, building, deploying, and running your application:

"scripts": {
  "lint": "eslint '*.ts' --quiet --fix",
  "format": "prettier --write '*.ts' '*.json'",
  "build": "npm run format && rm -rf dist && tsc",
  "deploy": "npm run build && serverless deploy",
  "offline": "npm run build && serverless offline"
}

lint: Runs ESLint to lint TypeScript files (*.ts) quietly (--quiet) with auto-fixing (--fix).
format: Formats TypeScript (*.ts) and JSON (*.json) files using Prettier.
build: Cleans the dist directory, formats TypeScript and JSON files (npm run format), and then compiles TypeScript (tsc).
deploy: Builds the project (npm run build) and deploys it using Serverless Framework (serverless deploy).
offline: Similar to deploy, but starts a local serverless environment (serverless offline) for testing.

These scripts help streamline development, testing, and deployment processes for your serverless application. Adjust them based on your specific project requirements and environment configurations.

Environment Variables

To run your application locally or deploy it to AWS Lambda, you need to set up a .env file in the root of your project. This file should contain sensitive information such as API keys or database connection strings. In this case, the .env file is used to store the MONGO_URI variable required for connecting to MongoDB.

Make sure to replace your_mongodb_uri_here with your actual MongoDB connection URI in the .env file before running or deploying your application.

License

This project is licensed under the MIT License.

dedeard/lambda-typescript-starter