Coupon Take

A complete solution to redeem random codes from a web API, the back-end was made in ASP.NET and the front-end in Flutter.

Techs

• Flutter
• ASP.NET
  • Ocelot
  • JWT
  • Argon2
• EntityFramework
• Docker
• Postgres

Setup

You will need Docker, Docker Compose and OpenSSL to setup and run the project. Flutter will be used to build the project for web, there is no good Flutter image to get the job done, so we ganna do by own. If you are running in a enviroment that don't have Flutter and don't want to install you can just skip the step, on the actions tab you will find project builds that you can just download, but is highly recommended that you build by your self.

The Docker will be used to build the images and run the containers and the Docker Composer is to create a cluster with all APIs and services running on. The OpenSSL is just to create the RSA keys used by CouponTakeInfra.Auth to sign the JWTs.

Clone the repository

git clone https://github.com/LuanRoger/CouponTake.git
cd CouponTake

Build the Flutter project for the web

flutter build web --release

NOTE: At the actual moment is preferable that the project is builded by Flutter in the beta channel, because some widget is not themed for Material 3 in the stable channel.

Create the the certificates

Firs create the path to store the public and private key that will be used to sign the JWTs. Create a folder called certificates on the CouponTake/CouponTakeInfra/ path:

mkdir CouponTakeInfra/certificates
cd CouponTakeInfra/certificates

Create the both public and private RSA key from thre:

openssl genrsa -out jwt-auth-priv-key.pem 4096
openssl rsa -in jwt-auth-priv-key.pem -pubout -out jwt-auth-pub-key.pem

Those keys will be copied to the container.

Build

Before build check the .env file and change if needed. Back to the root of the project (/CouponTake), build and start all the services with Docker Compose:

docker-compose up -d
# OR
docker compose up -d

There is a Dockerfile for each service used by docker-compose.yaml and you can build and run just what you want.

docker build -t <tag> -f <Dockerfile> .

Enter with the tag name that you prefer

Dockerfiles

• CouponTake (front-end): CouponTake/Dockerfile
• CouponTakeInfra.Gateway: CouponTake/CouponTakeInfra/Auth.Dockerfile
• CouponTakeInfra.Auth: CouponTake/CouponTakeInfra/Gateway.Dockerfile
• CouponTakeInfra.CouponGeneration: CouponTake/CouponTakeInfra/CouponGeneration.Dockerfile

If you choose to build and run each Dockerfile by own, keep in mind that you will need to pull the Postgres image from DockerHub

Projects overview

CouponTake (front-end/root) is the UI to communicate with the APIs/infrastructure, and the entrypoint for it is the CouponTakeInfra.Gateway that uses Ocelot to redirect the request to the right service.

One of them is CouponTakeInfra.Auth responsable to login and sign a user, it uses JWT to authorize the request. He also use Argon2 to to encript the user's password to store into Postgres. The last one is the CouponTakeInfra.CouponGeneration, this service just create a new coupon code (aka GUID lol) and get informations from the database about it.

graph LR;
    front([CouponTake])-->CouponTake.Gateway;
    CouponTake.Gateway-->CouponTake.Auth;
    CouponTake.Gateway-->CouponTake.CouponGeneration;
    CouponTake.CouponGeneration-->db[(PostgresDB)];
    CouponTake.Auth-->db[(PostgresDB)];

Screenshots

Screenshot

☁️ Deploy

You can easily deploy this project at DigitalOcean.