AbstractLoadBalancerAutoConfigurationTests.java

/*
 * Copyright 2012-present 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;

import java.net.URI;
import java.util.Collection;
import java.util.Map;
import java.util.Random;

import org.junit.jupiter.api.Test;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.AutoConfigurations;
import org.springframework.boot.restclient.autoconfigure.service.HttpClientServiceProperties;
import org.springframework.boot.test.context.runner.ApplicationContextRunner;
import org.springframework.cloud.client.DefaultServiceInstance;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.reactive.LoadBalancerWebClientHttpServiceGroupConfigurer;
import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.context.annotation.Primary;
import org.springframework.web.client.RestClient;
import org.springframework.web.client.RestTemplate;

import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.BDDAssertions.then;
import static org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancer.REQUEST;

/**
 * @author Ryan Baxter
 * @author Tim Ysewyn
 * @author Olga Maciaszek-Sharma
 */
public abstract class AbstractLoadBalancerAutoConfigurationTests {

	protected ApplicationContextRunner applicationContextRunner = new ApplicationContextRunner()
		.withConfiguration(AutoConfigurations.of(LoadBalancerAutoConfiguration.class));

	@Test
	void restTemplateGetsLoadBalancerInterceptor() {
		applicationContextRunner.withUserConfiguration(OneRestTemplate.class).run(context -> {
			final Map<String, RestTemplate> restTemplates = context.getBeansOfType(RestTemplate.class);

			then(restTemplates).isNotNull();
			then(restTemplates.values()).hasSize(1);
			RestTemplate restTemplate = restTemplates.values().iterator().next();
			then(restTemplate).isNotNull();

			assertLoadBalanced(restTemplate);
		});
	}

	@Test
	void restClientBuilderWithLoadBalancerInterceptor() {
		applicationContextRunner.withUserConfiguration(OneRestClientBuilder.class).run(context -> {
			final Map<String, RestClient.Builder> restClientBuilders = context.getBeansOfType(RestClient.Builder.class);

			assertThat(restClientBuilders).isNotNull();
			assertThat(restClientBuilders).hasSize(1);
			RestClient.Builder restClientBuilder = restClientBuilders.values().iterator().next();
			assertThat(restClientBuilder).isNotNull();
			assertLoadBalanced(restClientBuilder);
		});
	}

	@Test
	void multipleRestTemplates() {
		applicationContextRunner.withUserConfiguration(TwoRestTemplatesAndTwoRestClientBuilders.class).run(context -> {
			final Map<String, RestTemplate> restTemplates = context.getBeansOfType(RestTemplate.class);

			then(restTemplates).isNotNull();
			Collection<RestTemplate> templates = restTemplates.values();
			then(templates).hasSize(2);

			TwoRestTemplatesAndTwoRestClientBuilders.Two two = context
				.getBean(TwoRestTemplatesAndTwoRestClientBuilders.Two.class);

			then(two.loadBalanced).isNotNull();
			assertLoadBalanced(two.loadBalanced);

			then(two.nonLoadBalanced).isNotNull();
			then(two.nonLoadBalanced.getInterceptors()).isEmpty();
		});
	}

	@Test
	void multipleRestClientBuilders() {
		applicationContextRunner.withUserConfiguration(TwoRestTemplatesAndTwoRestClientBuilders.class).run(context -> {
			final Map<String, RestClient.Builder> restClientBuilders = context.getBeansOfType(RestClient.Builder.class);

			assertThat(restClientBuilders).isNotNull();
			assertThat(restClientBuilders.values()).hasSize(2);

			TwoRestTemplatesAndTwoRestClientBuilders.Two two = context
				.getBean(TwoRestTemplatesAndTwoRestClientBuilders.Two.class);

			assertThat(two.loadBalancedRestClientBuilder).isNotNull();
			assertLoadBalanced(two.loadBalancedRestClientBuilder);

			assertThat(two.nonLoadBalancedRestClientBuilder).isNotNull();
			two.nonLoadBalancedRestClientBuilder
				.requestInterceptors(interceptors -> assertThat(interceptors).isEmpty());
		});
	}

	@Test
	void restTemplatesAndRestClientsFromUsersAutoConfiguration() {
		applicationContextRunner
			.withConfiguration(AutoConfigurations.of(TwoRestTemplatesAndTwoRestClientBuilders.class))
			.run(context -> {
				final Map<String, RestClient.Builder> restClientBuilders = context
					.getBeansOfType(RestClient.Builder.class);
				final Map<String, RestTemplate> restTemplates = context.getBeansOfType(RestTemplate.class);

				assertThat(restClientBuilders).isNotNull();
				assertThat(restClientBuilders.values()).hasSize(2);

				TwoRestTemplatesAndTwoRestClientBuilders.Two two = context
					.getBean(TwoRestTemplatesAndTwoRestClientBuilders.Two.class);

				assertThat(two.loadBalancedRestClientBuilder).isNotNull();
				assertLoadBalanced(two.loadBalancedRestClientBuilder);

				assertThat(two.nonLoadBalancedRestClientBuilder).isNotNull();
				two.nonLoadBalancedRestClientBuilder
					.requestInterceptors(interceptors -> assertThat(interceptors).isEmpty());

				assertThat(restTemplates).isNotNull();
				Collection<RestTemplate> templates = restTemplates.values();
				assertThat(templates).hasSize(2);

				TwoRestTemplatesAndTwoRestClientBuilders.Two twoRestTemplate = context
					.getBean(TwoRestTemplatesAndTwoRestClientBuilders.Two.class);

				assertThat(twoRestTemplate.loadBalanced).isNotNull();
				assertLoadBalanced(twoRestTemplate.loadBalanced);

				assertThat(twoRestTemplate.nonLoadBalanced).isNotNull();
				assertThat(twoRestTemplate.nonLoadBalanced.getInterceptors()).isEmpty();
			});
	}

	@Test
	void loadBalancerRestClientHttpServiceGroupConfigurerPresent() {
		applicationContextRunner.withUserConfiguration(OneRestClientBuilder.class).run(context -> {
			assertThat(context.getBeansOfType(LoadBalancerRestClientHttpServiceGroupConfigurer.class)).hasSize(1);
			assertThat(context.getBeansOfType(LoadBalancerWebClientHttpServiceGroupConfigurer.class)).hasSize(0);
		});
	}

	protected abstract void assertLoadBalanced(RestClient.Builder restClientBuilder);

	protected abstract void assertLoadBalanced(RestTemplate restTemplate);

	@Configuration(proxyBeanMethods = false)
	@Import(BaseConfiguration.class)
	protected static class OneRestTemplate {

		@LoadBalanced
		@Bean
		RestTemplate loadBalancedRestTemplate() {
			return new RestTemplate();
		}

	}

	@Configuration(proxyBeanMethods = false)
	@Import(BaseConfiguration.class)
	protected static class OneRestClientBuilder {

		@LoadBalanced
		@Bean
		RestClient.Builder loadBalancedRestClientBuilder() {
			return RestClient.builder();
		}

		@Bean
		HttpClientServiceProperties httpClientServiceProperties() {
			return new HttpClientServiceProperties();
		}

	}

	@Configuration(proxyBeanMethods = false)
	protected static class BaseConfiguration {

		@Bean
		LoadBalancerClient loadBalancerClient() {
			return new NoopLoadBalancerClient();
		}

		@Bean
		ReactiveLoadBalancer.Factory<ServiceInstance> loadBalancerFactory(LoadBalancerProperties properties) {
			return new TestLoadBalancerFactory(properties);
		}

	}

	@Configuration(proxyBeanMethods = false)
	@Import({ OneRestTemplate.class, OneRestClientBuilder.class })
	protected static class TwoRestTemplatesAndTwoRestClientBuilders {

		@Primary
		@Bean
		RestTemplate restTemplate() {
			return new RestTemplate();
		}

		@Primary
		@Bean
		RestClient.Builder restClientBuilder() {
			return RestClient.builder();
		}

		@Configuration(proxyBeanMethods = false)
		protected static class Two {

			@Autowired
			RestTemplate nonLoadBalanced;

			@Autowired
			@LoadBalanced
			RestTemplate loadBalanced;

			@Autowired
			RestClient.Builder nonLoadBalancedRestClientBuilder;

			@Autowired
			@LoadBalanced
			RestClient.Builder loadBalancedRestClientBuilder;

		}

	}

	private static class NoopLoadBalancerClient implements LoadBalancerClient {

		private final Random random = new Random();

		@Override
		public ServiceInstance choose(String serviceId) {
			return choose(serviceId, REQUEST);
		}

		@Override
		public <T> ServiceInstance choose(String serviceId, Request<T> request) {
			return new DefaultServiceInstance(serviceId, serviceId, serviceId, this.random.nextInt(40000), false);
		}

		@Override
		public <T> T execute(String serviceId, LoadBalancerRequest<T> request) {
			try {
				return request.apply(choose(serviceId, REQUEST));
			}
			catch (Exception e) {
				throw new RuntimeException(e);
			}
		}

		@Override
		public <T> T execute(String serviceId, ServiceInstance serviceInstance, LoadBalancerRequest<T> request) {
			try {
				return request.apply(choose(serviceId, REQUEST));
			}
			catch (Exception e) {
				throw new RuntimeException(e);
			}
		}

		@Override
		public URI reconstructURI(ServiceInstance instance, URI original) {
			return DefaultServiceInstance.getUri(instance);
		}

	}

	private static class TestLoadBalancerFactory implements ReactiveLoadBalancer.Factory<ServiceInstance> {

		private final LoadBalancerProperties properties;

		TestLoadBalancerFactory(LoadBalancerProperties properties) {
			this.properties = properties;
		}

		@Override
		public ReactiveLoadBalancer<ServiceInstance> getInstance(String serviceId) {
			throw new UnsupportedOperationException("Not implemented.");
		}

		@Override
		public Object getInstance(String name, Class clazz, Class[] generics) {
			throw new UnsupportedOperationException("Not implemented.");
		}

		@Override
		public Map getInstances(String name, Class type) {
			throw new UnsupportedOperationException("Not implemented.");
		}

		@Override
		public LoadBalancerProperties getProperties(String serviceId) {
			return properties;
		}

	}

}