edssn / ticketing

Ticketing App

Ticketing App is a project developed to learn about the operation of Microservices and Event Driven Architectures.

• Users can list a ticket for an event(concert, sport) for sale
• Other users can purchase this ticket
• Any user can list tickets for sale and purchase tickets
• When user attempt to puchase a ticket, the ticket is locked for 15 minutes. The user has 15 minutes to enter their payment info
• While locked, no other user can purchase the ticket. After 15 minutes, the ticket should unlock
• Ticket process can be edited if they are not locked

What did I learn in this project?

• What are event-driven architectures and how do they work?
• How communication between microservices is done with an event bus.
• How to handle concurrency problems in event-driven architectures.
• TTD - Test Drive Development in NodeJS World.
• JEST and how configure it with NodeJS (Mocking imports with JEST).

This project was developed in Ubuntu 22.04 with Docker and Kubernets and developed with React and NodeJS.

Microservices

Option	Description
auth	Everything related to user (signup/signin/signout).
tickets	Ticket creation/editing. Knows whether a ticket can be updated
orders	Order creation/editing.
expiration	Watches for orders to be created, cancel them after 15 minutes.
payments	Handles credit card payments. Cancel orders if payments fails, completes if payment succeeds

Microservices Events

Auth

UserCreated UserUpdated

Orders

OrderCreated OrderCancelled OrderExired

Tickets

TicketCreated TicketUpdated

Payments

PaymentCreated

Tecnology

BackEnd	FrontEnd	Database	CI/CD	Event Bus
NodeJS (Teste with v16.20)	React	Mongo/Redis	Skaffold / Github Actions	Nats-Streaming

Requeriments

1. Docker.
2. Kubernets Cluster. I used minikube (https://minikube.sigs.k8s.io/docs/start/).
3. Ingress Controller created on kubernets. I used ingress-inginx to minikube (https://kubernetes.github.io/ingress-nginx/deploy/#minikube)
4. Skaffold (optional). Skaffold makes it easier develop and deploy the entire app (skaffol dev). You can create all deployments one by one. (https://skaffold.dev/docs/install/)
5. Postman. Postman is used to test endpoints.
6. At final, execute the following commands to kubernets cluster.

kubectl create secret generic jwt-secret --from-literal=JWT_KEY=asdf
kubectl create secret generic stripe-secret --from-literal=STRIPE_KEY=sk_test...

Value for STRIPE_KEY can be get from STRIPE developer console . Se more info in payments folder.

Common Error Response Structure

{
    errors: {
        message: string,
        field?: string    // optional
    } [] // array 
}

Kubernets Secrets

You need to execute the following command in order to create necesary secrets

kubectl create secret generic jwt-secret --from-literal=JWT_KEY=asdf
kubectl create secret generic stripe-secret --from-literal=STRIPE_KEY=sk_test...