Spring Boot Microservices

This Springboot project contains services:

1. Inventory Service: to store and validate inventory in a MySQL database.
2. Order Service: receives orders and stores order data in a MySQL database.
3. Product Serices: stores the product in a MongoDB database.

discovery-server uses Spring Netflix Eureka as Service Discovery server. All the above mentioned services are client to the discovery-server.

All these services can communicate with each other using Spring Webflux.

Uses

• Spring Cloud
• TestContainers
• Hibernate
• MockedMvc
• Spring Webflux
• Spring Netflix Eureka

Spring Netflix Eureka Setup

Step 1 : Modify pom.xml

Add the following in pom.xml of parent project:

<properties>
    ...
    <spring-cloud.version>2021.0.2</spring-cloud.version>
</properties>
<dependencyManagement>
        <dependencies>
            ...
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

In pom.xml of discovery-server:

<dependencies>
        ...
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
</dependencies>

For rest of the services add the following in pom.xml:

<dependency>
          <groupId>org.springframework.cloud</groupId>
          <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

Step 2 : Update applications.properties file

In application.properties of discovery-server add the following lines:

eureka.instance.hostname=localhost
eureka.client.register-with-eureka=false
eureka.client.fetch-registry=false
eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka
server.port=8761

The property eureka.client.register-with-eureka=false avoids Eureka server to register with itself as a client and make it act as a server. Another property eureka.client.fetch-registry=false tells Eureka server to don't search for other registry nodes. Both these properties are mandatory to add in the application.properties.

For the remaining services, the application.properties should look something like this:

server.port=8081
eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/
spring.application.name=order-service # For order-service

Step 3 : Use Annotations

For the server module, use @EnableEurekaServer on the main class.

For the other services, use @EnableEurekaClient or @EnableDiscoveryClient on their main classes depending on the version of Spring Cloud.

Hit the URL http://localhost:8761/ to see the Eureka Dashboard. Please make sure the Spring Cloud version and the Spring Boot version are compatible with each other to avoid Whitelable error page.