tiny-url

Serverless AWS application without a DB to shorten urls. Inspired by this article.

Disclaimer

This application is not meant to be used in production. The ressources created by terraform are only created with basic settings and are not suitable for production. This application is only meant to be used as a demo and give some insights on how to create a serverless tiny-url application on AWS.

You can refer to the What's missing / What can be improved section to see what can be improved to make this application production ready.

Pre-requisites

Terraform >= 1.0.0
Node.js >= 18 & npm >= 9
AWS account
AWS_ACCESS_KEY_ID & AWS_SECRET_ACCESS_KEY environment variables set so terraform can create the ressources on your AWS account

What's included

A S3 bucket that host a static website with public read access and a 7 days lifecycle policy.
A basic http api gateway with a single POST endpoint that call a lambda function.
A lambda function that takes an url as a input, validated by a zod schema, and return a link to a S3 object that redirect to the original url. The S3 key is validated to make sure that it is not overwriting anything.
All created by terraform.

How it works

When you call the tiny-url endpoint, the lambda function is called with the url you want to shorten as input. The lambda function then create a new empty object in the s3 bucket with a random name and a custom metadata, x-amz-website-redirect-location, that contains the original url. S3 bucket that have static website hosting enable have the ability to treat objects with this metadata as a redirect. When you call the url of the object, you are redirected to the original url.

Usage

Clone the repository
Run npm install to install the dependencies
Run npm run build to build the lambda function
Go into the terraform folder
Run terraform init to initialize terraform
Run terraform apply to create the AWS ressources
- If you have an error that says the s3 bucket already exists, change the bucket name in the s3.tf file (line 2) and run terraform apply again. S3 bucket name are unique across AWS.
For some reason terraform doesn't deploy the api gateway integration correctly, so will do it manually.
- Enter into the API Gateway console in AWS and click on http-api-gateway in the api list.
- On the left panel, click on Integrations. You should already be on the POST route, if not, click on POST in the routes panel.
- Click the Manage integration button in the Integration details for route panel.
- Click on the Edit button in the Integration details panel.
- Simply hit the Save button in the Edit integration panel without changing anything.
Find the url of your api gateway stage in AWS and call the API_GATEWAY_URL/tiny-url endpoint with a POST request and a body like this: { "url": "https://www.google.com" }
You should get a response like this: { "url": "http://tiny-url-bucket-dev.s3-website-us-east-1.amazonaws.com/gG_n2" }
Go to the url you got in the response and you should be redirected to the original url.
When you are done, delete all the files in your s3 bucket then run terraform destroy to destroy the AWS ressources.

What's missing / What can be improved

Change the http api gateway to a rest api gateway with full configuration and custom domain name.
A cloudfront distribution in front of the s3 bucket to serve the static website.
A custom Route53 domain name to the cloudfront distribution that serve the s3 bucket to shorten the url.
A protection to the endpoint that create the shortened url to avoid abuse (docs).