/* * 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.openfeign.loadbalancer; import java.io.IOException; import java.net.URI; import java.nio.charset.StandardCharsets; import feign.Client; import feign.Request; import feign.Response; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.cloud.client.ServiceInstance; import org.springframework.cloud.client.loadbalancer.LoadBalancerClient; import org.springframework.http.HttpStatus; import org.springframework.util.Assert; /** * A {@link Client} implementation that uses {@link LoadBalancerClient} to select a * {@link ServiceInstance} to use while resolving the request host. * * @author Olga Maciaszek-Sharma * @since 2.2.0 */ public class FeignBlockingLoadBalancerClient implements Client { private static final Log LOG = LogFactory .getLog(FeignBlockingLoadBalancerClient.class); private final Client delegate; private final LoadBalancerClient loadBalancerClient; public FeignBlockingLoadBalancerClient(Client delegate, LoadBalancerClient loadBalancerClient) { this.delegate = delegate; this.loadBalancerClient = loadBalancerClient; } @Override public Response execute(Request request, Request.Options options) throws IOException { final URI originalUri = URI.create(request.url()); String serviceId = originalUri.getHost(); Assert.state(serviceId != null, "Request URI does not contain a valid hostname: " + originalUri); ServiceInstance instance = loadBalancerClient.choose(serviceId); if (instance == null) { String message = "Load balancer does not contain an instance for the service " + serviceId; if (LOG.isWarnEnabled()) { LOG.warn(message); } return Response.builder().request(request) .status(HttpStatus.SERVICE_UNAVAILABLE.value()) .body(message, StandardCharsets.UTF_8).build(); } String reconstructedUrl = loadBalancerClient.reconstructURI(instance, originalUri) .toString(); Request newRequest = Request.create(request.httpMethod(), reconstructedUrl, request.headers(), request.body(), request.charset(), request.requestTemplate()); return delegate.execute(newRequest, options); } // Visible for Sleuth instrumentation public Client getDelegate() { return delegate; } }