Make ApplicationDiscoveryListener customizable

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/config/DiscoveryClientConfiguration.java

@@ -18,8 +18,9 @@ package de.codecentric.boot.admin.config;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnSingleCandidate;
 import org.springframework.cloud.client.discovery.DiscoveryClient;
 import org.springframework.cloud.client.discovery.noop.NoopDiscoveryClientAutoConfiguration;
 import org.springframework.context.annotation.Bean;
@@ -29,7 +30,7 @@ import de.codecentric.boot.admin.discovery.ApplicationDiscoveryListener;
 import de.codecentric.boot.admin.registry.ApplicationRegistry;
 
 @Configuration
-@ConditionalOnClass({ DiscoveryClient.class })
+@ConditionalOnSingleCandidate(DiscoveryClient.class)
 @ConditionalOnProperty(prefix = "spring.boot.admin.discovery", name = "enabled", matchIfMissing = true)
 @AutoConfigureAfter({ NoopDiscoveryClientAutoConfiguration.class })
 public class DiscoveryClientConfiguration {
@@ -44,6 +45,7 @@ public class DiscoveryClientConfiguration {
 	private ApplicationRegistry registry;
 
 	@Bean
+	@ConditionalOnMissingBean
 	public ApplicationDiscoveryListener applicationDiscoveryListener() {
 		ApplicationDiscoveryListener listener = new ApplicationDiscoveryListener(discoveryClient,
 				registry);

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/discovery/ApplicationDiscoveryListener.java

@@ -73,7 +73,7 @@ public class ApplicationDiscoveryListener {
 		}
 	}
 
-	public void discover() {
+	protected void discover() {
 		for (String serviceId : discoveryClient.getServices()) {
 			for (ServiceInstance instance : discoveryClient.getInstances(serviceId)) {
 				registry.register(convert(instance));
@@ -81,7 +81,7 @@ public class ApplicationDiscoveryListener {
 		}
 	}
 
-	private Application convert(ServiceInstance instance) {
+	protected Application convert(ServiceInstance instance) {
 		String serviceUrl = append(instance.getUri().toString(), serviceContextPath);
 		String managementUrl = append(instance.getUri().toString(), managementContextPath);
 		String healthUrl = append(managementUrl, healthEndpoint);
@@ -102,7 +102,7 @@ public class ApplicationDiscoveryListener {
 		this.healthEndpoint = healthEndpoint;
 	}
 
-	private String append(String uri, String path) {
+	protected final String append(String uri, String path) {
 		String baseUri = uri.replaceFirst("/+$", "");
 		if (StringUtils.isEmpty(path)) {
 			return baseUri;