🌱 Microservices with Spring Cloud

 • Spring Cloud Gateway
 • Eureka Discovery
 • Open Feign Rest Client
 • Hystrix DashBoard 

Project Class Diagram

Table of contents

• Customer Service
• Inventory Service
• Gateway Service
• Eureka Discovery Service
• Billing Service

Customer Service

Create a new Spring project :

Selected dependencies

• Spring Web 
• Spring Data JPA 
• H2 Database
• Rest Repositories 
• Lombok
• Spring Boot DevTools
• Eureka Discovery Client
• Spring Boot Actuator 

Application Configuration application.properties

spring.application.name=customer-service
spring.datasource.url=jdbc:h2:mem:customers-db
spring.cloud.discovery.enabled=true
#management.endpoints.web.exposure.include=*
server.port=8888

Steps :

1. Create Customer entity

package ma.enset.customermicroservice.entites;

import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

@Entity
@Data @NoArgsConstructor @AllArgsConstructor @ToString
public class Customer {
  @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long id;
  private String name;
  private String email;
}

2. Create CustomerRepository Spring Data based interface

package ma.enset.customermicroservice.repository;

import ma.enset.customermicroservice.entites.Customer;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.rest.core.annotation.RepositoryRestResource;

@RepositoryRestResource
public interface CustomerRepository extends JpaRepository<Customer, Long> {
}

3. Deploy Restful API of microservice with Spring Data Rest

4. Microservice test

Customers	Find Customer By Id
Actuator	Actuator Health

Database H2

Inventory Service

Application Configuration application.properties

spring.application.name=inventory-service
spring.datasource.url=jdbc:h2:mem:products-db
spring.cloud.discovery.enabled=true
server.port=8889

Steps :

1. Create Product entity
2. Create ProductRepository Spring Data based interface
3. Deploy Restful API of microservice with Spring Data Rest
4. Microservice test

All Products

Database

Gateway Service

Selected dependencies

• Gateway 
• Spring Boot Actuator
• Hystrix 
• Eureka Discovery Client 

1. Static routes configuration : application.yml / application.properties

application.properties

spring.application.name=gateway-service
spring.cloud.discovery.enabled=true
server.port=8890

application.yml

spring:
  cloud:
    gateway:
      routes:
        - id : r1
          uri : http://localhost:8888/
          predicates :
            - Path= /customers/**
        - id : r2
          uri : http://localhost:8889/
          predicates :
            - Path= /products/**

Access to All Customers from Gateway

Access to All Products from Gateway

2. Static routes configuration : Java Config Class

    @Bean
    RouteLocator routeLocator(RouteLocatorBuilder builder){
        return builder.routes()
                .route("r1", (r) -> r.path("/customers/**").uri("http://localhost:8888/"))
                .route("r2", (r) -> r.path("/products/**").uri("http://localhost:8889/"))
                .build();
    }

Access to All Customers from Gateway

Access to All Products from Gateway

3. Eureka Discovery Service : Dynamic Routing

Eureka Discovery Service

Selected dependencies

• Eureka Server

EnableEurekaServer

@SpringBootApplication
@EnableEurekaServer
public class EurekaDiscoveryApplication {
    public static void main(String[] args) {
        SpringApplication.run(EurekaDiscoveryApplication.class, args);
    }
}

application.properties

server.port=8761
# dont register server itself as a client.
eureka.client.fetch-registry=false
# Does not register itself in the service registry.
eureka.client.register-with-eureka=false

Eureka Spring

Static routes configuration with Discovery Service

    @Bean
    RouteLocator routeLocator(RouteLocatorBuilder builder){
        return builder.routes()
                .route("r1", (r) -> r.path("/customers/**").uri("lb://CUSTOMER-SERVICE"))
                .route("r2", (r) -> r.path("/products/**").uri("lb://INVENTORY-SERVICE"))
                .build();
    }

Access to All Customers from Gateway

Access to All Products from Gateway

Dynamic routes configuration with Discovery Service

    @Bean
    DiscoveryClientRouteDefinitionLocator definitionLocator(ReactiveDiscoveryClient rdc,
                                                            DiscoveryLocatorProperties dlp){
        return new DiscoveryClientRouteDefinitionLocator(rdc, dlp);
    }

Access to All Customers from Gateway

Access to All Products from Gateway

Billing Service

Selected dependencies

• OpenFeign 
• Spring HATEOAS

Service Test

Bill Complet Informations
Bill Complet Informations	Access to All Products from Gateway

II - Front End Part with Angular :

Link to Front End part.