Spring Boot 3.3.0 and later versions bring many enhancements and changes. One crucial aspect of modern microservices architecture is service discovery, and Netflix Eureka is a popular choice for this purpose. In this detailed blog, we will guide you through setting up a Eureka Server and registering microservices with it using Spring Boot 3.3.0 or newer.
Table of Contents
Introduction to Eureka Server
Setting Up the Eureka Server
Configuring Eureka Clients
Running and Testing the Setup
Conclusion
1. Introduction to Eureka Server
Netflix Eureka is a REST-based service registry for resilient mid-tier load balancing and failover. It provides a way for services to register themselves and to discover other registered services. This is particularly useful in microservices architecture to manage service instances dynamically.
2. Setting Up the Eureka Server
Step 1: Create a New Spring Boot Project
You can use Spring Initializr to create a new Spring Boot project. Ensure you include the Eureka Server dependency.
pom.xml:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<!– Other dependencies as required –>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>2023.0.0</version> <!– Replace with the latest BOM version –>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
Step 2: Enable Eureka Server
Create a main application class and annotate it with @EnableEurekaServer.
EurekaServerApplication.java:
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@SpringBootApplication
@EnableEurekaServer
public class EurekaServerApplication {
public static void main(String[] args) {
SpringApplication.run(EurekaServerApplication.class, args);
}
}
Step 3: Configure Application Properties
Configure the application properties to set up the Eureka server.
application.yml:
port: 8761
eureka:
client:
register-with-eureka: false
fetch-registry: false
server:
wait-time-in-ms-when-sync-empty: 0
spring:
application:
name: eureka-server
Step 4: Run the Eureka Server
Run the application. Your Eureka Server should now be up and running at http://localhost:8761.
3. Configuring Eureka Clients
Next, let’s set up a Eureka client (a microservice that registers itself with the Eureka server).
Step 1: Create a New Spring Boot Project for the Client
Again, use Spring Initializr to create a new Spring Boot project for the client. Include the Eureka Client dependency.
pom.xml:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<!– Other dependencies as required –>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>2023.0.0</version> <!– Replace with the latest BOM version –>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
Step 2: Enable Eureka Client
Create the main application class and annotate it with @EnableEurekaClient.
EurekaClientApplication.java:
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
@SpringBootApplication
@EnableEurekaClient
public class EurekaClientApplication {
public static void main(String[] args) {
SpringApplication.run(EurekaClientApplication.class, args);
}
}
Step 3: Configure Application Properties
Configure the application properties to register the client with the Eureka server.
application.yml:
port: 8080
spring:
application:
name: eureka-client
eureka:
client:
service-url:
defaultZone: http://localhost:8761/eureka/
Step 4: Create a Simple REST Controller
Create a simple REST controller to test the Eureka client.
GreetingController.java:
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class GreetingController {
@GetMapping(“/greeting”)
public String greeting() {
return “Hello from Eureka Client!”;
}
}
Step 5: Run the Eureka Client
Run the Eureka client application. It should register itself with the Eureka server.
4. Running and Testing the Setup
Start the Eureka Server: Run the Eureka server application. Access the Eureka dashboard at http://localhost:8761. You should see an empty registry initially.
Start the Eureka Client: Run the Eureka client application. After a few moments, the client should appear in the Eureka dashboard, indicating successful registration.
Access the Client Service: You can access the client service at http://localhost:8080/greeting. This will return “Hello from Eureka Client!”.
5. Conclusion
Setting up a Eureka server and client in Spring Boot 3.3.0+ is straightforward thanks to the robust support provided by Spring Cloud Netflix. By following this guide, you can establish a reliable service discovery mechanism for your microservices architecture, enhancing the scalability and resilience of your applications.
Summary
Setup Eureka Server: Create a Spring Boot project, include the Eureka Server dependency, configure it, and run.
Setup Eureka Client: Create a separate Spring Boot project, include the Eureka Client dependency, configure it, create a simple REST controller, and run.
Test the Setup: Verify the client registration in the Eureka dashboard and test the client service endpoint.
With Eureka in place, your microservices can dynamically discover and communicate with each other, simplifying load balancing and fault tolerance management. This setup forms a solid foundation for building and scaling a resilient microservices ecosystem.
