Eureka Getting List of Services

Question

How can I fetch the already registered service from eureka?

The below code gives the details about a particular service. But I want the list of the registered services .

Code:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@EnableDiscoveryClient
@SpringBootApplication
public class EurekaClientApplication {

    public static void main(String[] args) {
        SpringApplication.run(EurekaClientApplication.class, args);
    }
}

@RestController
class ServiceInstanceRestController {

    @Autowired
    private DiscoveryClient discoveryClient;

    @RequestMapping("/service-instances/{applicationName}")
    public List<ServiceInstance> serviceInstancesByApplicationName(
            @PathVariable String applicationName) {
        return this.discoveryClient.getInstances(applicationName);
    }
}

Answer 1

Pretty simple really :)

        List<Application> applications = discoveryClient.getApplications().getRegisteredApplications();

    for (Application application : applications) {
        List<InstanceInfo> applicationsInstances = application.getInstances();
        for (InstanceInfo applicationsInstance : applicationsInstances) {

            String name = applicationsInstance.getAppName();
            String url = applicationsInstance.getHomePageUrl();
            System.out.println(name + ": " + url);
        }
    }

Answer 2

Or, and if you like don't want to drag in the whole world of spring-boot/Eureka libs and prefer a "clean" thin client, you can just perform a simple GET towards

http://<eureka host>:<port>/eureka/apps

as is described here Using Eureka as a registry using REST APIs or, and as we do it, utilize springboot admin's API (described here https://codecentric.github.io/spring-boot-admin/1.5.7/ for instance) and just do a simple GET towards

http://<springbootadmin host>:<port>/api/applications

while providing login credentils using a Basic auth header, ie

"Basic", java.util.Base64.getEncoder().encodeToString(("<springboot admin user>" + ":" + "<pwd>").getBytes());

You'll then get a nice JSON response easily parsed into collections of java objects utilizing JSON-attributes

private String name; // service name
private String managementUrl; // an url from which host and port can be easily grabbed 
private StatusInfo statusInfo; // telling whether this service instance is up or down

for instance. Add proper toString()-based hashcode() and equals() and you have something rather proper to work with whether you want to work with sets of running services "on any instance" or unique instances.