Add loadbalancing sample.

STATUS.adoc

@@ -47,6 +47,11 @@ h|test
 |image:https://ci.spring.io/api/v1/teams/spring-checkpoint-restore-smoke-tests/pipelines/spring-checkpoint-restore-smoke-tests-3.2.x/jobs/context-refresh-http-cr-app-test/badge[link=https://ci.spring.io/teams/spring-checkpoint-restore-smoke-tests/pipelines/spring-checkpoint-restore-smoke-tests-3.2.x/jobs/context-refresh-http-cr-app-test]
 |image:https://ci.spring.io/api/v1/teams/spring-checkpoint-restore-smoke-tests/pipelines/spring-checkpoint-restore-smoke-tests-3.2.x/jobs/context-refresh-http-test/badge[link=https://ci.spring.io/teams/spring-checkpoint-restore-smoke-tests/pipelines/spring-checkpoint-restore-smoke-tests-3.2.x/jobs/context-refresh-http-test]
 
+|loadbalancing
+|image:https://ci.spring.io/api/v1/teams/spring-checkpoint-restore-smoke-tests/pipelines/spring-checkpoint-restore-smoke-tests-3.2.x/jobs/loadbalancing-app-test/badge[link=https://ci.spring.io/teams/spring-checkpoint-restore-smoke-tests/pipelines/spring-checkpoint-restore-smoke-tests-3.2.x/jobs/loadbalancing-app-test]
+|image:https://ci.spring.io/api/v1/teams/spring-checkpoint-restore-smoke-tests/pipelines/spring-checkpoint-restore-smoke-tests-3.2.x/jobs/loadbalancing-cr-app-test/badge[link=https://ci.spring.io/teams/spring-checkpoint-restore-smoke-tests/pipelines/spring-checkpoint-restore-smoke-tests-3.2.x/jobs/loadbalancing-cr-app-test]
+|
+
 |===
 
 == Data

ci/smoke-tests.yml

@@ -18,6 +18,9 @@ groups:
      - name: context-refresh-http
        app_test: true
        test: true
+     - name: loadbalancing
+       app_test: true
+       test: false
   - name: data
     smoke_tests:
      - name: data-jdbc

cloud/loadbalancing/build.gradle

@@ -0,0 +1,26 @@
+plugins {
+	id "java"
+	id "org.springframework.boot"
+	id "org.springframework.cr.smoke-test"
+}
+
+// Not using Spring Cloud bom due to existing issues with dependency management
+ext {
+	set('springCloudCommonsVerions', "4.1.0-SNAPSHOT")
+}
+
+dependencies {
+	implementation(platform(org.springframework.boot.gradle.plugin.SpringBootPlugin.BOM_COORDINATES))
+	implementation("org.springframework.boot:spring-boot-starter-webflux")
+	implementation("org.crac:crac:$cracVersion")
+	implementation(project(":cr-listener"))
+	implementation("org.springframework.cloud:spring-cloud-starter-loadbalancer:${springCloudCommonsVerions}")
+
+	testImplementation("org.springframework.boot:spring-boot-starter-test")
+
+	appTestImplementation(project(":cr-smoke-test-support"))
+}
+
+crSmokeTest {
+	webApplication = true
+}

cloud/loadbalancing/docker-compose.yml

@@ -0,0 +1,9 @@
+services:
+  test-service:
+    image: springcloud/test-service:latest
+    ports:
+      - "8081"
+  demo-service:
+    image: springcloud/demo-service:latest
+    ports:
+      - "8082"

cloud/loadbalancing/src/appTest/java/com/example/loadbalancing/LoadBalancerApplicationTests.java

@@ -0,0 +1,23 @@
+package com.example.loadbalancing;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.cr.smoketest.support.junit.ApplicationTest;
+import org.springframework.test.web.reactive.server.WebTestClient;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@ApplicationTest
+class LoadBalancerApplicationTests {
+
+	@Test
+	void loadBalancing(WebTestClient webClient) {
+		webClient.get()
+			.exchange()
+			.expectStatus()
+			.isOk()
+			.expectBody()
+			.consumeWith(result -> assertThat(new String(result.getResponseBodyContent())).isEqualTo("testdemo"));
+	}
+
+}

cloud/loadbalancing/src/main/java/com/example/loadbalancing/LoadBalancerApplication.java

@@ -0,0 +1,32 @@
+package com.example.loadbalancing;
+
+import com.example.loadbalancing.service.LoadBalancerClientTestService;
+import reactor.core.publisher.Flux;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@SpringBootApplication
+public class LoadBalancerApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(LoadBalancerApplication.class, args);
+	}
+
+	@RestController
+	static class TestController {
+
+		@Autowired
+		private LoadBalancerClientTestService testService;
+
+		@GetMapping("/")
+		public Flux<String> test() {
+			return testService.callServices();
+		}
+
+	}
+
+}

cloud/loadbalancing/src/main/java/com/example/loadbalancing/client/DemoServiceClient.java

@@ -0,0 +1,24 @@
+package com.example.loadbalancing.client;
+
+import java.net.URI;
+
+import reactor.core.publisher.Mono;
+
+import org.springframework.cloud.client.loadbalancer.LoadBalanced;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@Component
+public class DemoServiceClient {
+
+	private final WebClient webClient;
+
+	public DemoServiceClient(@LoadBalanced WebClient.Builder builder) {
+		this.webClient = builder.build();
+	}
+
+	public Mono<String> demo() {
+		return webClient.get().uri(URI.create("http://demo-service")).retrieve().bodyToMono(String.class);
+	}
+
+}

cloud/loadbalancing/src/main/java/com/example/loadbalancing/client/TestServiceClient.java

@@ -0,0 +1,24 @@
+package com.example.loadbalancing.client;
+
+import java.net.URI;
+
+import reactor.core.publisher.Mono;
+
+import org.springframework.cloud.client.loadbalancer.LoadBalanced;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@Component
+public class TestServiceClient {
+
+	private final WebClient webClient;
+
+	public TestServiceClient(@LoadBalanced WebClient.Builder builder) {
+		this.webClient = builder.build();
+	}
+
+	public Mono<String> test() {
+		return webClient.get().uri(URI.create("http://test-service")).retrieve().bodyToMono(String.class);
+	}
+
+}

cloud/loadbalancing/src/main/java/com/example/loadbalancing/config/CustomLoadBalancerConfiguration.java

@@ -0,0 +1,47 @@
+package com.example.loadbalancing.config;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.loadbalancer.CompletionContext;
+import org.springframework.cloud.client.loadbalancer.LoadBalancerLifecycle;
+import org.springframework.cloud.client.loadbalancer.Request;
+import org.springframework.cloud.client.loadbalancer.Response;
+import org.springframework.context.annotation.Bean;
+
+public class CustomLoadBalancerConfiguration {
+
+	@Bean
+	LoadBalancerLifecycle<Object, Object, ServiceInstance> loadBalancerLifecycle() {
+		return new TestLoadBalancerLifecycle();
+	}
+
+	static class TestLoadBalancerLifecycle implements LoadBalancerLifecycle<Object, Object, ServiceInstance> {
+
+		private static final Log LOG = LogFactory.getLog(TestLoadBalancerLifecycle.class);
+
+		@Override
+		public void onStart(Request<Object> request) {
+			if (LOG.isInfoEnabled()) {
+				LOG.info("On Start: " + request);
+			}
+		}
+
+		@Override
+		public void onStartRequest(Request<Object> request, Response<ServiceInstance> lbResponse) {
+			if (LOG.isInfoEnabled()) {
+				LOG.info("On Start Request: " + request + ", LB response: " + lbResponse);
+			}
+		}
+
+		@Override
+		public void onComplete(CompletionContext<Object, ServiceInstance, Object> completionContext) {
+			if (LOG.isInfoEnabled()) {
+				LOG.info("On Complete: " + completionContext);
+			}
+		}
+
+	}
+
+}

cloud/loadbalancing/src/main/java/com/example/loadbalancing/config/WebClientConfig.java

@@ -0,0 +1,19 @@
+package com.example.loadbalancing.config;
+
+import org.springframework.cloud.client.loadbalancer.LoadBalanced;
+import org.springframework.cloud.loadbalancer.annotation.LoadBalancerClient;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@Configuration
+@LoadBalancerClient(name = "test-service", configuration = CustomLoadBalancerConfiguration.class)
+public class WebClientConfig {
+
+	@LoadBalanced
+	@Bean
+	WebClient.Builder webClientBuilder() {
+		return WebClient.builder();
+	}
+
+}

cloud/loadbalancing/src/main/java/com/example/loadbalancing/service/LoadBalancerClientTestService.java

@@ -0,0 +1,26 @@
+package com.example.loadbalancing.service;
+
+import com.example.loadbalancing.client.DemoServiceClient;
+import com.example.loadbalancing.client.TestServiceClient;
+import reactor.core.publisher.Flux;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class LoadBalancerClientTestService {
+
+	private final TestServiceClient testServiceClient;
+
+	private final DemoServiceClient demoServiceClient;
+
+	public LoadBalancerClientTestService(TestServiceClient testServiceClient, DemoServiceClient demoServiceClient) {
+		this.testServiceClient = testServiceClient;
+		this.demoServiceClient = demoServiceClient;
+
+	}
+
+	public Flux<String> callServices() {
+		return testServiceClient.test().concatWith(demoServiceClient.demo());
+	}
+
+}

cloud/loadbalancing/src/main/resources/application.yml

@@ -0,0 +1,12 @@
+spring:
+  application:
+    name: loadbalancer-client
+  cloud:
+    discovery:
+      client:
+        simple:
+          instances:
+            test-service:
+              - uri: http://${TEST-SERVICE_HOST:localhost}:${TEST-SERVICE_PORT_8081:8081}
+            demo-service:
+              - uri: http://${DEMO-SERVICE_HOST:localhost}:${DEMO-SERVICE_PORT_8082:8082}