Party Reservation

An application to make party reservations.

Design

The Use Case

I would like to make a party reservation(via Reservation Entry) such that it instantly shows my RSVP on the doorman's iPad(via Reservation Confirmation). If my name is not there, I will not be allowed to enter the party.

The Problem

Consumer microservices typically are bound to know or have some level of knowledge about the domain of the Producer microservice especially when the communication between a Consumer microservice and a Producer microservice is done via HTTP. The problem of really not coupling your microservices becomes a challenge especially in the case when there are more Producer microservices that the Consumer microservice depends on.

The Goal

So the idea here is that we can decouple microservices through messaging as opposed to REST/communication via HTTP. The other great thing about this approach is that the producing microservice will not have to care about what type of technology/stack/language the consumer uses as the consumer will only just consume messages from Kafka. The Reservation-Entry service is the producer and sends messages to Kafka and the Confirmation service is the consumer application which will consume messages from Kafka and send data as Server Sent Events to the client.

The Reservation-Entry service is a Reactive Spring Application that uses the normal Spring Kafka to publish data onto the Kafka queue that our Confimation service will consume. This application will be in charge of writing/publishing to the queue.

The Confirmation service is a Reactive Spring Application that uses the Project Reactor Kafka library to consume from kafka reactively and send data to the client reactively. This application will only be reading events from the queue only.

Swagger

Reservation Confirmation Service

http://localhost:8081/webjars/swagger-ui/index.html?configUrl=/v3/api-docs/swagger-config

Docker

• To start both microservices in docker you need to run: docker-compose up or docker-compose up -d without the daemon attached to your console.
• This will start the confirmation service on localhost:8081 and the reservation service on localhost:8080
• To stop the services from running while the daemon is attached to your console you need to run ctrl + c.

Testing

• Testing on both confirm microservice and reservation-entry microservice is done at the unit test level.