Microservices / REST / RabbitMQ

:octocat: /drestaurant-apps/drestaurant-monolith-rest :octocat:

This is a thin layer which coordinates the application activity. It does not contain business logic. It does not hold the state of the business objects

We designed and structured our loosely coupled components in a modular way, and that enable us to choose different deployment strategy and take first step towards Microservices architectural style.

Each microservice:

has its own bounded context,
has its own JPA event(sourcing) store (we are not sharing the JPA Event Store)
we distribute events between them via RabbitMQ
and we distribute commands (Command Bus) by Spring Cloud discovery and registry service (Eureka)

RabbitMQ & event messages

RabbitMQ is the most popular open source message broker. It is used to route and distribute events. It supports several messaging protocols, directly and through the use of plugins:

AMQP
STOMP
MQTT
HTTP …

This messaging pattern supports delivering a message to multiple consumers.

We configured our (micro)services to use publish-subscribe model, by setting unique queue for each (micro)service. This queues are bind to one common exchange (events.fanout.exchange).

RabbitMQ allows more sophisticated message routing then Apache Kafka can offer. Having one exchange bind to every service queue covered our scenario, but you can do more if you like.

Spring Cloud connector & command messages

The Spring Cloud connector setup uses the service registration and discovery mechanism described by Spring Cloud for distributing the command bus (commands). You are thus left free to choose which Spring Cloud implementation to use to distribute your commands. An example implementation is the Eureka Discovery/Eureka Server combination.

Restaurant management

Read all restaurants

curl http://localhost:8084/restaurants

Create new restaurant

curl -i -X POST --header 'Content-Type: application/json' --header 'Accept: */*' -d '{
"menuItems": [
 {
   "id": "id1",
   "name": "name1",
   "price": 100
 }
],
"name": "Fancy"
}' 'http://localhost:8084/restaurants'

Mark restaurant order as prepared

curl -i -X PUT --header 'Content-Type: application/json' --header 'Accept: */*' 'http://localhost:8084/restaurants/RESTAURANT_ID/orders/RESTAURANT_ORDER_ID/markprepared'

Customer management

Read all customers

curl http://localhost:8082/customers

Create/Register new Customer

curl -i -X POST --header 'Content-Type: application/json' --header 'Accept: */*' -d '{
"firstName": "Ivan",
"lastName": "Dugalic",
"orderLimit": 1000
}' 'http://localhost:8082/customers'

Courier management

Read all couriers

curl http://localhost:8081/couriers

Create/Hire new Courier

curl -i -X POST --header 'Content-Type: application/json' --header 'Accept: */*' -d '{
"firstName": "John",
"lastName": "Doe",
"maxNumberOfActiveOrders": 20
}' 'http://localhost:8081/couriers'

Courier takes/claims the Order that is ready for delivery (prepared)

curl -i -X PUT --header 'Content-Type: application/json' --header 'Accept: */*' 'http://localhost:8081/couriers/COURIER_ID/orders/COURIER_ORDER_ID/assign'

Courier marks the order as delivered

curl -i -X PUT --header 'Content-Type: application/json' --header 'Accept: */*' 'http://localhost:8081/couriers/COURIER_ID/orders/COURIER_ORDER_ID/markdelivered'

Order management

Read all orders

 curl http://localhost:8083/orders

Create/Place the Order

curl -i -X POST --header 'Content-Type: application/json' --header 'Accept: */*' -d '{
"customerId": "CUSTOMER_ID",
"orderItems": [
 {
   "id": "id1",
   "name": "name1",
   "price": 100,
   "quantity": 0
 }
],
"restaurantId": "RESTAURANT_ID"
}' 'http://localhost:8083/orders'

Note: Replace CUSTOMER_ID and RESTAURANT_ID with concrete values.

Development

This project is driven using Maven.

Clone

$ git clone https://github.com/idugalic/digital-restaurant

Build

$ cd digital-restaurant
$ mvn clean install

Run microservices

NOTE: Docker is required. We use it to start RabbitMQ

$ docker run -d --hostname my-rabbit --name some-rabbit -p 15672:15672 -p 5672:5672 rabbitmq:3-management
$ cd digital-restaurant/drestaurant-apps/drestaurant-microservices-rest/drestaurant-microservices-rest-courier
$ mvn spring-boot:run
$ cd digital-restaurant/drestaurant-apps/drestaurant-microservices-rest/drestaurant-microservices-rest-discovery-server
$ mvn spring-boot:run
$ cd digital-restaurant/drestaurant-apps/drestaurant-microservices-rest/drestaurant-microservices-rest-customer
$ mvn spring-boot:run
$ cd digital-restaurant/drestaurant-apps/drestaurant-microservices-rest/drestaurant-microservices-rest-restaurant
$ mvn spring-boot:run
$ cd digital-restaurant/drestaurant-apps/drestaurant-microservices-rest/drestaurant-microservices-rest-order
$ mvn spring-boot:run