Lab 22

Steps and Files

1. Eureka Server
2. @EnableEurekaServer annotation
   • EurekaserverApplication.java
3. application.yml
   • application.yml
4. eurekaserver.yml
   • eurekaserver.yml
5. Start Configserver and Eureka Server
6. Eureka Dashboard
7. Register Microservices with Eureka
   • pom.xml
8. Accounts application.yml
   • application.yml
9. Eureka Dashboard, Accounts
10. Accounts Acuator/info endpoint
11. Eureka Dashboard, Loans and Cards

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Lab#22 Service discovery with Eureka

Spring Cloud Netflix’s Eureka service which will act as a service discovery agent In this lab we will setup a Eureka server and register the microservices with Eureka.

Server Side

1. Eureka Server

Step#1 Create a new project using spring initializer. The dependencies that we need are the Eureka Server, the Config Client and the Spring Boot Actuator

Figure 1. Eureka Server Spring Initializer

2. @EnableEurekaServer annotation

Step#2 Open the EurekaserverApplication class and add the @EnableEurekaServer annotation.

package com.tus.eurekaserver;

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);
    }
}

3. application.yml

Step#3 Rename the application.properties to application.yml and update as follows:

spring:
  application:
    name: "eurekaserver"
  config:
    import: "optional:configserver:http://localhost:8071" # Lab 22
management:
  endpoints:
    web:
      exposure:
        include: "*" # Lab 19
  health:
    readinessState:
      enabled: true # Lab 22
    livenessState:
      enabled: true # Lab 22
  endpoint:
    health:
      probes:
        enabled: true # Lab 22

4. eurekaserver.yml

Step#4 In the bitbucket/github repo add a eurekaserver.yml file. The eureka server only needs one profile.

server:
  port: 8070

eureka:
  instance:
    hostname: localhost
  client:
    fetch-registry: false
    registerWithEureka: false
    serviceUrl:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

5. Start Configserver and Eureka Server

Step#5 Start the configserver first, followed by the eureka server. Check that the properties are read correctly.

Start Configserver and Eureka Server and test Accounts prod properties

localhost:8071/accounts/prod

Figure 2. Read accounts/prod properties

Start Configserver and Eureka Server and test Eureka Server default properties

localhost:8071/eurekaserver/default

Figure 3. Read eurekaserver/default properties

6. Eureka Dashboard

Step#6 Go to the eureka dashboard. No services currently registered with eureka

Figure 4. Eureka Dashboard

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Client Side

7. Register Microservices with Eureka

Step#7 Now we will update the microservices to register themselves with eureka. First of all we have to add a dependency to the pom files for the accounts microservice.

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

8. Accounts application.yml

Step#8 Make the following changes to the application.yml for the accounts microservice.

  config:
   import: "configserver:http://localhost:8071/" # config server port 8071
  cloud:
    compatibility-verifier:
      enabled: false # disable version check
management:
  endpoints:
    web:
      exposure:
        # include: "*" # Lab 19
        include: info, shutdown # lab 22
  endpoint:
    shutdown:
      enabled: true
    info:
      env:
        enabled: true

eureka:
  instance:
    preferIpAddress: true
  client:
    fetchRegistry: true
    registerWithEureka: true
    serviceUrl:
      defaultZone: http://localhost:8070/eureka

info:
  app:
    name: "accounts"
    description: "Bank Accounts Application"
    version: "1.0.0"

9. Eureka Dashboard, Accounts

Step#9 Restart the accounts microservice and check in the eureka dashboard that one instance of the accounts microservice has registered.

Figure 5. Eureka Dashboard, Accounts Registered

10. Accounts Acuator/info endpoint

Step#10 check on the accounts instance and the actuator/info endpoint should show the data for the microservice.

192.168.56.1:8081/actuator/info

Figure 6. actuator/info endpoint

11. Eureka Dashboard, Loans and Cards

Step#11 Make similar changes in the loans and cards microservices. Restart them and check eureka dashboard.

Figure 7. Eureka Dashboard, Loans and Cards Registered