NX AWS SAM MONOREPO

A Monorepo Starter for Serverless Node.js Applications with AWS SAM and Github Actions Pre-Configured 🚀

Features

✔️ NX Monorepo

✔️ Microservices Auto Generators

✔️ Node.js and TypeScript

✔️ Serverless Architecture

✔️ AWS Lambda

✔️ AWS SAM and SAM Templates

✔️ Github Actions

✔️ ESLint

✔️ Jest

✔️ Husky

✔️ ESBuild

Prerequisites

• Node.js
• Docker
• AWS Account
• S3 Bucket for Saving the SAM Artifacts
• AWS CLI
• AWS SAM CLI

Getting Started

• Clone the Repository.
• Add your AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY to the repository secrets under: Settings -> Secrets -> Actions and click the New repository secret button. At the end, it should look like that:

• Add your S3 bucket for saving SAM artifacts in:
  • tools -> generators -> service -> index.ts and change the value of samBucketName to your S3 bucket name.
  • Search for the placeholder <BUCKET_NAME> and replace it with your S3 bucket name.
• Run npm install.

Commands

// Run all services
npm run lint 
npm run test
npm run build
npm run deploy

// Run only affected services
npm run affected:lint 
npm run affected:test
npm run affected:build
npm run affected:deploy

// Run specific service
nx lint <SERVICE_NAME>
nx test <SERVICE_NAME>
nx build <SERVICE_NAME>
nx deploy <<SERVICE_NAME>
nx remove <SERVICE_NAME>

Generate a Service

Run npm run generate:service <SERVICE_NAME> to generate a new service.

For Example: npm run generate:service auth will generate a new service under services directory that is called auth-service.

Remove a Service

Run npm run remove <SERVICE_NAME> to remove an existing service.

NOTE: This command will also remove the corresponding CloudForamtion stack in AWS.

Deletes an AWS SAM application by deleting the AWS CloudFormation stack, the artifacts that were packaged and deployed to Amazon S3 and Amazon ECR, and the AWS SAM template file.

For Example: npm run remove auth-service will remove the auth-service from the services directory and the corresponding AWS CloudFormation stack.

AWS SAM and SAM Template

AWS SAM and SAM Template (template.yaml) allows you to deploy your stack to AWS with ease. It helps you to use ALL AWS resources in the template.yaml. When you will deploy your service, the pipeline will take the build and the template.yaml and deploy it to AWS with all the relevant resources that you defined in the template.

The default template.yaml in the project uses the API Gateway resource with GET and POST methods for each of the Lambda functions:

  Events:
    ApiEvent:
      Type: Api
      Properties:
        Path: /
        Method: GET
        RestApiId: !Ref RestApiGateway

  Events:
    ApiEvent:
      Type: Api
      Properties:
        Path: /
        Method: POST
        RestApiId: !Ref RestApiGateway

More about AWS SAM, SAM Templates and AWS resources can be found here.

CI/CD Pipeline with Github Actions

The project contains 3 pre-configured GitHub Actions pipelines:

• pr: Triggered by open a PR.
• dev: Triggered by push to the dev branch.
• prod: Triggered by push to the main branch.

The PR pipeline executes the following steps only on the affected services:

• Runs code linting.
• Runs tests.

Each environment pipeline (dev/prod) executes the following steps only on the affected services:

• Runs code linting.
• Runs tests.
• Builds the service.
• Deploys the service to AWS.

You can add or modify the workflow files for your needs.

Manual Deployment

You can deploy your service manually to AWS with the following command:

$ npm run build <SERVICE_NAME> --  --args='--EnvType=dev'
$ npm run deploy <SERVICE_NAME> --  --args='--EnvType=dev'

For Example: npm run deploy auth-service -- --args='--EnvType=dev' will deploy ALL the Lambdas of auth-service with dev prefix. It will create dev-auth-service stack, and if we have for example the CreateUserFunction, it will create a Lambda that is called dev-auth-service-CreateUserFunction.

Cloud Environment Variables

For the different enviroments (dev, prod, etc), you can use AWS Secret Manager or AWS SSM Parameter Store to store your Lambda/service enviroment variables. You can reference the enviroment variables within your template.yaml. In that way, the environment variables will be injected into the Lambda runtime on the deploy process.

For example (notice the Environment section):

Globals:
  Function:
    Timeout: 3
    MemorySize: 128
    Runtime: nodejs16.x
    Tracing: Active
    AutoPublishAlias: !Ref EnvType
    Architectures:
      - arm64
    Environment:
      Variables:
        TABLE_NAME: '{{resolve:secretsmanager:user-service/prod:SecretString:TABLE_NAME}}'

More about referencing enviroment variables within template.yaml can be found here.

Local Environment Variables

.env.json file:

To run your functions locally, each service should have its own .env.json file. So in each service directory you should create the .env.json file with the following structure:

{
    "Parameters": {}
}

For Example:

{
    "Parameters": {
        "TABLE_NAME": "localtable",
        "BUCKET_NAME": "testBucket",
    }
}

If you have more than one function in the service/stack, you can define the environment variables for each function in the same file.

For Example:

{
    "GetUserFunction": {
        "TABLE_NAME": "localtable1",
        "BUCKET_NAME": "testBucket1",
    },
    "AddUserFunction": {
        "TABLE_NAME": "localtable2",
        "BUCKET_NAME": "testBucket2",
    }
}

When you invoke your service's Lambda funtions locally, it will load the enviroment variables from the .env.json file.

.env.template.json file:

When you generate a new service, it will create also the .env.template.json file. The purpose of this file is to share only the keys of the environment variables between all the developers that work on this project. So, when developer clone the project he will know the environment variables that he should have in the project and ask for the values from other developers.

More about local enviroment variables can be found here.

Local Development

To make local development and testing of Lambda functions easier, you can invoke Lambda functions locally without deploying them to AWS. Moreover, you can invoke them with different events and resources like API, SQS, etc.

NOTE: To run/invoke your functions locally, your Docker should be running on your machine.

Build your application by running the following command:

$ npm run build <SERVICE_NAME>

For Example:

$ npm run build auth-service

This command builds any dependencies that your service has, and copies your service source code to folders under .aws-sam/build to be zipped and uploaded to Lambda.

Generate events like SQS, S3, etc:

You can generate and customize event payloads for a variety of AWS services like API Gateway, Amazon S3, AWS SQS, etc, then, you can use the generated event to invoke the Lambda function. Generate event by running the following command:

$ npm run generate:event <SERVICE_NAME> sqs receive-message

For Example:

$ npm run generate:event auth-service sqs receive-message

The event will be generated in the event.json file that in the service directory. More about the different events can be found here.

Run functions locally and invoke them with the following command:

$ npm run invoke:lambda <SERVICE_NAME> <FUNCTION_NAME>

For Example:

$ npm run invoke:lambda auth-service GetUserFunction

When you run the Lambda locally, it will load the environment variables from the .env.json file and use the event.json file to invoke the Lambda.

Invoke specific service functions with API call:

To start your function's Amazon API Gateway locally to test HTTP request/response, use the following command:

$ npm run invoke:api <SERVICE_NAME>

For Example:

$ npm run invoke:api user-service
$ curl http://localhost:3001/

When you run this command, it creates a local HTTP server that hosts all of your service functions.

This functionality features hot reloading so that you can quickly develop and iterate over your functions. You do not need to restart/reload while working on your functions, changes will be reflected instantly/automatically. You only need to restart if you update your AWS SAM template.

NOTE: The port 3001 may be in use in your machine, if so, when running the above command you will get the following error: OSError: [Errno 48] Address already in use. All you need to do is change the port in worksapce.json to avaliable port and run the command again.

More about test, debug and invoke functions locally with AWS SAM, can be found here.

Further help

• Visit AWS SAM Documentation to learn more about AWS SAM framework
• Visit the Nx Documentation to learn more