Serverless Typescript AWS fro Zemoga Cahellenge

This is a Serverless project example using Typescript, ready for AWS Lambda and API Gateway.

You need to have an AWS account, to create a dedicated IAM User with credentials so Serverless can deploy your app. (Configure AWS credentials)

Stack

Node.js 12x
Serverless
Typescript (> 3.8) for type checking.
docker-compose.yml, which allow us run the App with Docker.

IDE Setup

VSCode is highly preferred. Please ensure you have installed these extensions:

Prettier
Eslint

Requirements

Node.js

Use our node container (set up in docker-compose.yml)

Or install Node 16 : https://nodejs.org/en/

Serverless

npm install -g serverless

Local DynamoDB:

sls dynamodb install

NPM Scripts

Let's add some scripts for our application in package.json

"scripts": {
  "lint": "eslint . --ext js,ts --cache --fix",
  "prettier": "prettier --list-different './**/*.{js,ts}'",
  "typecheck": "tsc --noEmit",
  "test": "echo \"Error: no test specified\" && exit 1"
},

Test them :

# linter
npm run lint

# prettier
npm run prettier

# type checking
npm run typecheck

Configure AWS Credentials (Quick way)

This is the quick way to set up a user for Serverless.

Here is a better way : Configure AWS Credentials (Better way)

Create IAM user for Serverless

Login to AWS and navigate to IAM
Create a new user called serverless-deploy
Give serverless-deploy Programatic access
Attach the AdministratorAccess policy

Use your user credentials

Save your new AWS profile into ~/.aws/credentials (Don't forget to set your values :D) :

[serverless-deploy]
aws_access_key_id = XXX
aws_secret_access_key = XXX
region = XXX

Set this profile in your serverless.yml so Serverless can use it for deployment.

provider:
    profile: serverless-deploy

(or pass it with --profile argument to serverless deploycommand.)

Deploy

# -v enables verbose output so you can see what happens
serverless deploy -v

You can test it with your API Gateway end point : https://xxxxxx.execute-api.us-east-1.amazonaws.com/dev

The command to invoke a service is:

# -f specifies the function name, -l specifiesto output the logs to the console
serverless invoke -f hello -l

If you want to run the service locally you can run:

npm run dev

Delete your service

serverless remove

Configure AWS Credentials (Better way)

Create IAM user, IAM group and IAM Policy

Here we want to create a new IAM Policy, attach it to a new IAM group to which we will attach our new user.

Let's go to Identity and Access Management (IAM) service and create a new User serverless-deploy with Programatic access. Give it no permissions.

You can find how to use your user credentials with Serverless here : Use your user credentials

Then try to deploy your serverless app

serverless deploy -v

Let's now create a new IAM Policy :

Create a new IAM Policy
Add a policy for the CloudFormation service, allow List:DescribeStacks action.
Indicate to apply this permission to all resources and click Review Policy button.
(If necessary, you can specify specific ressources to apply the permissions)
Name this policy serverless-deploy-policy (just for consistency) and finish to create it.

Now go back to the group serverless-deploy-group we created and attach it this policy.
Then go back to the user serverless-deploy and attach it to the group serverless-deploy-group.

Let's now try to deploy again

serverless deploy -v

AWS Policies configuration

You can find the required policies configuration here: IAM.json

Total Time

The total time that I spent in the project was: 12 hours.

danfercf1/zemoga-challenge