my-aws-sandbox

TD/TR

This is my sandbox AWS Serverless stack.

I'm sorry I haven't updated for a long time. Now that CDK v2 is available and my stack has a lot of customization, I don't see time to update it. Maybe in the future!

Big Picture

Limitations

This is a single repository stack. In one place, as a single CDK deployment, we are creating everything needed to deliver a working application.

AWS vendor locked-in

AWS

• CDK
• Lambda
• API Gateway
• DynamoDB
• X-RAY
• CloudWatch

TypeScript

• prettier (clean code)
• eslint (perfect code)
• jest (tested)
• ajv (validated data structures)

thanks

🍺🍺🍺 for Oskar Dudycz for the template to the project:

• Github Action configuration
• node.js configuration (prettier, eslint, tsconfig)

Build

npm install
npm run build

This will install the necessary CDK, then this example's dependencies, and then build your TypeScript files and CloudFormation template.

Deploy

Prerequisites

npm install -g aws-cdk

Deployment needed commands

npm run deploy

npx cdk deploy --profile name-of-the-profile

Development

CDK

Add new resources

1. Extend the CdkResources class with new item based on the convention
2. Implement resources instance for CdkResources with new item name
3. use generateResourceName function to generate the resource name based on the convention

Enable traceability for each resource:

• for RestApi
• for lambda please use lambdaFactory helper to generate CDK lambda with all needed setup

Automatic tests

For now, we support a humao.rest-client with VS code HTTP tests. Please remember for automatic and manual test -> to not spam PROD environment use automatic-test for *requestId header.

Decisions log

use the github markdown emoji markup to show type for decision

Architecture

:cloud:

Event Driven Architecture

Event Bus

1. At first - find the best messaging system for you. Use AWS link. My solution is focused and vendor-locked with AWS.
2. Is important to have a possibility to add more than one event target.

To deliver lousily coupled architecture the best option is to use the EventBridge:

• relatively cheap
• max 5 targets

Outbox pattern

1. One source of truth for the data (users table).
2. Process data only persisted in the database (Start payment process, etc.)

Lambda

KISS

Code should be simple:

• easy to read
• easy to maintain
• easy to test (less code to cover)
• easy to rewrite ;)
• easy to remove

Lambda to handle API Gateway request

The lambda is written as simple as possible. This is a microservice, so logic should be so 'easy' and hope in this can be migrated without any refactoring into hexagonal architecture.
On the picture there is a flow inside the lambda. There is a Service Layer with the dedicated model from the Lambda event. All in one service validate data and store it in the database.

helpers

dynamodb-factory

• creates the document client for DynamoDB
• wrap client with X-RAY

function dynamoClient(region?: string): DynamoDB.DocumentClient

CDK

how-to-use

install or update on the environment

npm install -g aws-cdk@latest

cdk-helpers

lambdaFactory

• returns Function with default values
• based on the convention uses handler: 'index.handler'

webpack

Handlers located in handlers folder, each in a dedicated folder with the name as index.ts. Use npm run build to make the deployment handler for CDK.

development configuration

    mode: "development",
    optimization: {
        minimize: false,
        usedExports: true,
    },

production configuration

 mode: 'production',

check the lambda package size

enable plugin

    plugins: [
        new BundleAnalyzerPlugin()
    ],