Initial support for DiscoveryClientEndpoint and LoadBalancerEndpoint

Supplies actuator endpoints for commons methods on these interfaces.

spring-cloud-commons/src/main/java/org/springframework/cloud/client/discovery/endpoint/DiscoveryClientEndpoint.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2013-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.client.discovery.endpoint;
+
+import java.util.List;
+
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
+import org.springframework.boot.actuate.endpoint.annotation.ReadOperation;
+import org.springframework.boot.actuate.endpoint.annotation.Selector;
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.discovery.ReactiveDiscoveryClient;
+
+@Endpoint(id = "discovery")
+public class DiscoveryClientEndpoint {
+
+	private final ReactiveDiscoveryClient discoveryClient;
+
+	public DiscoveryClientEndpoint(ReactiveDiscoveryClient discoveryClient) {
+		this.discoveryClient = discoveryClient;
+	}
+
+	@ReadOperation
+	public Mono<List<String>> services() {
+		return this.discoveryClient.getServices().collectList();
+	}
+
+	@ReadOperation
+	public Mono<List<ServiceInstance>> instances(@Selector String serviceId) {
+		Flux<ServiceInstance> instances = this.discoveryClient.getInstances(serviceId);
+		return instances.collectList();
+	}
+
+}

spring-cloud-commons/src/main/java/org/springframework/cloud/client/discovery/endpoint/DiscoveryClientEndpointAutoConfiguration.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2013-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.client.discovery.endpoint;
+
+import org.springframework.boot.actuate.autoconfigure.endpoint.condition.ConditionalOnAvailableEndpoint;
+import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
+import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.cloud.client.discovery.ReactiveDiscoveryClient;
+import org.springframework.cloud.client.discovery.composite.CompositeDiscoveryClientAutoConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration(proxyBeanMethods = false)
+@ConditionalOnClass(Endpoint.class)
+@AutoConfigureAfter(CompositeDiscoveryClientAutoConfiguration.class)
+public class DiscoveryClientEndpointAutoConfiguration {
+
+	@Bean
+	@ConditionalOnAvailableEndpoint
+	@ConditionalOnBean(ReactiveDiscoveryClient.class)
+	public DiscoveryClientEndpoint discoveryClientEndpoint(
+			ReactiveDiscoveryClient discoveryClient) {
+		return new DiscoveryClientEndpoint(discoveryClient);
+	}
+
+}

spring-cloud-commons/src/main/java/org/springframework/cloud/client/discovery/simple/reactive/SimpleReactiveDiscoveryProperties.java

@@ -31,8 +31,6 @@ import org.springframework.cloud.client.ServiceInstance;
 import org.springframework.cloud.client.discovery.DiscoveryClient;
 import org.springframework.cloud.client.discovery.ReactiveDiscoveryClient;
 
-import static java.util.Collections.emptyList;
-
 /**
  * Properties to hold the details of a {@link ReactiveDiscoveryClient} service instance
  * for a given service. It also holds the user-configurable order that will be used to
@@ -57,7 +55,10 @@ public class SimpleReactiveDiscoveryProperties {
 	private int order = DiscoveryClient.DEFAULT_ORDER;
 
 	public Flux<ServiceInstance> getInstances(String service) {
-		return Flux.fromIterable(instances.getOrDefault(service, emptyList()));
+		if (instances.containsKey(service)) {
+			return Flux.fromIterable(instances.get(service));
+		}
+		return Flux.empty();
 	}
 
 	Map<String, List<SimpleServiceInstance>> getInstances() {

spring-cloud-commons/src/main/java/org/springframework/cloud/client/loadbalancer/reactive/ReactiveLoadBalancerAutoConfiguration.java

@@ -16,32 +16,45 @@
 
 package org.springframework.cloud.client.loadbalancer.reactive;
 
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.boot.actuate.autoconfigure.endpoint.condition.ConditionalOnAvailableEndpoint;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.cloud.client.ServiceInstance;
 import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
+import org.springframework.cloud.client.loadbalancer.reactive.endpoint.LoadBalancerEndpoint;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.web.reactive.function.client.WebClient;
 
 /**
- * @deprecated in favour of {@link ReactorLoadBalancerClientAutoConfiguration}
  * @author Spencer Gibb
  * @author Olga Maciaszek-Sharma
  */
 @Configuration(proxyBeanMethods = false)
-@ConditionalOnClass(WebClient.class)
-@ConditionalOnBean(LoadBalancerClient.class)
 @AutoConfigureAfter(ReactorLoadBalancerClientAutoConfiguration.class)
-@ConditionalOnMissingBean(ReactorLoadBalancerExchangeFilterFunction.class)
-@Deprecated
 public class ReactiveLoadBalancerAutoConfiguration {
 
 	@Bean
+	@ConditionalOnClass(
+			name = "org.springframework.web.reactive.function.client.WebClient")
+	@ConditionalOnMissingBean(ReactorLoadBalancerExchangeFilterFunction.class)
+	@ConditionalOnBean(LoadBalancerClient.class)
+	@Deprecated
 	public LoadBalancerExchangeFilterFunction loadBalancerExchangeFilterFunction(
 			LoadBalancerClient client) {
 		return new LoadBalancerExchangeFilterFunction(client);
 	}
 
+	@Bean
+	@ConditionalOnAvailableEndpoint
+	@ConditionalOnClass(
+			name = "org.springframework.boot.actuate.endpoint.annotation.Endpoint")
+	@ConditionalOnBean(ReactiveLoadBalancer.Factory.class)
+	public LoadBalancerEndpoint loadBalancerEndpoint(
+			ObjectProvider<ReactiveLoadBalancer.Factory<ServiceInstance>> clientFactory) {
+		return new LoadBalancerEndpoint(clientFactory);
+	}
+
 }

spring-cloud-commons/src/main/java/org/springframework/cloud/client/loadbalancer/reactive/endpoint/LoadBalancerEndpoint.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2013-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.client.loadbalancer.reactive.endpoint;
+
+import reactor.core.publisher.Mono;
+
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
+import org.springframework.boot.actuate.endpoint.annotation.ReadOperation;
+import org.springframework.boot.actuate.endpoint.annotation.Selector;
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancer;
+import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancer.Factory;
+
+@Endpoint(id = "loadbalancer")
+public class LoadBalancerEndpoint {
+
+	private final ObjectProvider<Factory<ServiceInstance>> clientFactory;
+
+	public LoadBalancerEndpoint(ObjectProvider<Factory<ServiceInstance>> clientFactory) {
+		this.clientFactory = clientFactory;
+	}
+
+	@ReadOperation
+	public Mono<ServiceInstance> choose(@Selector String serviceId,
+			@Selector String operation) {
+		if (!"choose".equalsIgnoreCase(operation)) {
+			return Mono.error(
+					new IllegalArgumentException("Unknown operation: " + operation));
+		}
+		Factory<ServiceInstance> factory = this.clientFactory.getIfAvailable();
+		if (factory == null) {
+			return Mono.empty();
+		}
+
+		ReactiveLoadBalancer<ServiceInstance> loadBalancer = factory
+				.getInstance(serviceId);
+		return Mono.from(loadBalancer.choose()).flatMap(response -> {
+			if (response.hasServer()) {
+				return Mono.just(response.getServer());
+			}
+			return Mono.empty();
+		});
+	}
+
+}

spring-cloud-commons/src/main/resources/META-INF/spring.factories

@@ -4,6 +4,7 @@ org.springframework.cloud.client.CommonsClientAutoConfiguration,\
 org.springframework.cloud.client.ReactiveCommonsClientAutoConfiguration,\
 org.springframework.cloud.client.discovery.composite.CompositeDiscoveryClientAutoConfiguration,\
 org.springframework.cloud.client.discovery.composite.reactive.ReactiveCompositeDiscoveryClientAutoConfiguration,\
+org.springframework.cloud.client.discovery.endpoint.DiscoveryClientEndpointAutoConfiguration,\
 org.springframework.cloud.client.discovery.noop.NoopDiscoveryClientAutoConfiguration,\
 org.springframework.cloud.client.discovery.simple.SimpleDiscoveryClientAutoConfiguration,\
 org.springframework.cloud.client.discovery.simple.reactive.SimpleReactiveDiscoveryClientAutoConfiguration,\

spring-cloud-commons/src/test/java/org/springframework/cloud/client/discovery/endpoint/DiscoveryClientEndpointTests.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright 2013-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.client.discovery.endpoint;
+
+import java.util.List;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringBootConfiguration;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.cloud.client.discovery.simple.reactive.SimpleReactiveDiscoveryProperties.SimpleServiceInstance;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.reactive.server.WebTestClient;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(properties = { "management.endpoints.web.exposure.include=discovery" },
+		webEnvironment = RANDOM_PORT)
+@ActiveProfiles("lbendpoint")
+public class DiscoveryClientEndpointTests {
+
+	@Autowired
+	private WebTestClient client;
+
+	@Test
+	public void servicesWorks() {
+		client.get().uri("/actuator/discovery").exchange().expectBody(List.class)
+				.consumeWith(result -> {
+					List<String> body = result.getResponseBody();
+					assertThat(body).contains("myservice", "anotherservice",
+							"thirdservice");
+				});
+
+	}
+
+	@Test
+	public void instancesWorks() {
+		client.get().uri("/actuator/discovery/myservice").exchange()
+				.expectBodyList(SimpleServiceInstance.class).consumeWith(result -> {
+					List body = result.getResponseBody();
+					assertThat(body).isNotEmpty();
+				});
+
+	}
+
+	@Test
+	public void noInstancesWorks() {
+		client.get().uri("/actuator/discovery/unknownservice").exchange()
+				.expectBodyList(SimpleServiceInstance.class).consumeWith(result -> {
+					List body = result.getResponseBody();
+					assertThat(body).isEmpty();
+				});
+
+	}
+
+	@SpringBootConfiguration
+	@EnableAutoConfiguration
+	protected static class TestConfiguration {
+
+	}
+
+}

spring-cloud-commons/src/test/java/org/springframework/cloud/client/loadbalancer/reactive/endpoint/LoadBalancerEndpointTests.java

@@ -0,0 +1,126 @@
+/*
+ * Copyright 2013-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.client.loadbalancer.reactive.endpoint;
+
+import java.util.Random;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import reactor.core.publisher.Mono;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringBootConfiguration;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.discovery.ReactiveDiscoveryClient;
+import org.springframework.cloud.client.discovery.simple.reactive.SimpleReactiveDiscoveryProperties.SimpleServiceInstance;
+import org.springframework.cloud.client.loadbalancer.reactive.CompletionContext;
+import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancer;
+import org.springframework.cloud.client.loadbalancer.reactive.Response;
+import org.springframework.context.annotation.Bean;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.reactive.server.WebTestClient;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(properties = { "management.endpoints.web.exposure.include=loadbalancer" },
+		webEnvironment = RANDOM_PORT)
+@ActiveProfiles("lbendpoint")
+public class LoadBalancerEndpointTests {
+
+	private static final Random random = new Random();
+
+	@Autowired
+	private WebTestClient client;
+
+	@Test
+	public void chooseWorks() {
+		client.get().uri("/actuator/loadbalancer/myservice/choose").exchange()
+				.expectBody(SimpleServiceInstance.class).consumeWith(result -> {
+					ServiceInstance body = result.getResponseBody();
+					assertThat(body).isNotNull();
+					assertThat(body.getHost()).isNotEmpty();
+				});
+
+	}
+
+	@Test
+	public void chooseWorksWithoutInstances() {
+		client.get().uri("/actuator/loadbalancer/unknownservice/choose").exchange()
+				.expectBody(SimpleServiceInstance.class).consumeWith(result -> {
+					ServiceInstance body = result.getResponseBody();
+					assertThat(body).isNull();
+					// TODO: web response 404?
+				});
+
+	}
+
+	static Mono<Response<ServiceInstance>> choose(ReactiveDiscoveryClient discoveryClient,
+			String serviceId) {
+		return discoveryClient.getInstances(serviceId).collectList().map(instances -> {
+			if (instances.isEmpty()) {
+				return new InstanceResponse(null);
+			}
+			int idx = random.nextInt(instances.size());
+			ServiceInstance instance = instances.get(idx);
+			return new InstanceResponse(instance);
+		});
+	}
+
+	private static final class InstanceResponse implements Response<ServiceInstance> {
+
+		private final ServiceInstance instance;
+
+		private InstanceResponse(ServiceInstance instance) {
+			this.instance = instance;
+		}
+
+		@Override
+		public boolean hasServer() {
+			return this.instance != null;
+		}
+
+		@Override
+		public ServiceInstance getServer() {
+			return this.instance;
+		}
+
+		@Override
+		public void onComplete(CompletionContext completionContext) {
+
+		}
+
+	}
+
+	@SpringBootConfiguration
+	@EnableAutoConfiguration
+	protected static class TestConfiguration {
+
+		@Bean
+		public ReactiveLoadBalancer.Factory<ServiceInstance> loadBalancerFactory(
+				ReactiveDiscoveryClient discoveryClient) {
+			return serviceId -> (ReactiveLoadBalancer<ServiceInstance>) request -> choose(
+					discoveryClient, serviceId);
+		};
+
+	}
+
+}

spring-cloud-commons/src/test/resources/application-lbendpoint.yml

@@ -0,0 +1,27 @@
+spring:
+  cloud:
+    discovery:
+      client:
+        simple:
+          instances:
+            myservice:
+              - service-id: myservice
+                uri: http://ahost:8080
+              - service-id: myservice
+                uri: http://chost:8081
+              - service-id: myservice
+                uri: https://bhostsecure:8082
+            anotherservice:
+              - service-id: myservice
+                uri: http://dhost:8180
+              - service-id: myservice
+                uri: https://fhost:8181
+              - service-id: myservice
+                uri: http://ehost:8182
+            thirdservice:
+              - service-id: myservice
+                uri: http://ghost:8280
+              - service-id: myservice
+                uri: http://hhost:8281
+              - service-id: myservice
+                uri: http://ihost:8282