Posted on Jan 16

Microservices Part 01: Creating Service Registry Application

#java #microservices #eurekaserver #serviceregistry

In order to create a Microservices Application we will first require a Service Registry which is nothing but a special kind of microservice that will have a list of microservices registered inside it.

There are total three steps to create a Service Registry.

Step1: We are going to write our Service Registry microservice application using the spring-cloud-starter-netflix-eureka-server dependency.

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>3.4.1</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.sky</groupId> <artifactId>service-registry</artifactId> <version>1.0</version> <name>service-registry</name> <description>Registry for Job Portal Application</description> <url/> <licenses> <license/> </licenses> <developers> <developer/> </developers> <scm> <connection/> <developerConnection/> <tag/> <url/> </scm> <properties> <java.version>21</java.version> <spring-cloud.version>2024.0.0</spring-cloud.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</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-test</artifactId> <scope>test</scope> </dependency> </dependencies> <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> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>

service-registry/pom.xml

Step 2: Now, we need to also include the annotation @EnableEurekaServer to notify that this particular application will act as a Registry Server.

package com.sky.service_registry; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer; @SpringBootApplication @EnableEurekaServer public class ServiceRegistryApplication { public static void main(String[] args) { SpringApplication.run(ServiceRegistryApplication.class, args); } }

service_registry/ServiceRegistryApplication.java

Step 3: We need to also specify the below details. To tell Spring to not register this application as a microservice. As all the other microservices will be registered inside this special microservice.

spring.application.name=service-registry server.port=8761 eureka.instance.hostname=localhost eureka.client.register-with-eureka=false eureka.client.fetch-registry=false

/service-registry/src/main/resources/application.properties

Step 4: We will create a new microservice and try to register it in the Service Registry that was created in the previous steps.

We need to add the spring-cloud-starter-netflix-eureka-client dependency in our pom.xml of the new microservice in order to make it available/discoverable for registeration in the Service Registry.

 <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</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-test</artifactId> <scope>test</scope> </dependency> </dependencies>

Step 5: Also, we have to add below configuration for newly created microservice to specify the url for eureka server i.e. our Service Registry.

spring.application.name=job-search-service server.port=8762 eureka.client.service-url.defaultZone=http://localhost:8761/eureka

Step 6: Now, make sure the Service Registry and the newly created microservice is running. To validate if the registration is success we can go to the Eureka Server URL(http://localhost:8761/) and locate the new microservice name there as shown in below snapshot.