Spring Cloud Gateway使用K8S (Kubernetes)的云原生服务发现

import org.springframework.cloud.gateway.route.RouteLocator;
import org.springframework.cloud.gateway.filter.factory.rewrite.Config;
import org.springframework.cloud.gateway.filter.factory.rewrite.ModifyResponseBodyGatewayFilterFactory;
import org.springframework.cloud.gateway.support.ConfigurationService;
import org.springframework.cloud.gateway.support.NotFoundException;
import org.springframework.cloud.gateway.support.ConfigurationProperties;
import org.springframework.cloud.gateway.discovery.DiscoveryClientRouteDefinitionLocator;
import org.springframework.cloud.gateway.discovery.DiscoveryLocatorProperties;
import org.springframework.cloud.kubernetes.discovery.KubernetesDiscoveryClient;
import org.springframework.cloud.kubernetes.discovery.KubernetesServiceInstance;
import org.springframework.cloud.kubernetes.discovery.KubernetesDiscoveryProperties;
 
@Configuration
public class KubernetesGatewayConfiguration {
 
    private final KubernetesDiscoveryClient kubernetesDiscoveryClient;
    private final KubernetesDiscoveryProperties kubernetesDiscoveryProperties;
 
    public KubernetesGatewayConfiguration(KubernetesDiscoveryClient kubernetesDiscoveryClient, KubernetesDiscoveryProperties kubernetesDiscoveryProperties) {
        this.kubernetesDiscoveryClient = kubernetesDiscoveryClient;
        this.kubernetesDiscoveryProperties = kubernetesDiscoveryProperties;
    }
 
    @Bean
    public DiscoveryClientRouteDefinitionLocator discoveryClientRouteDefinitionLocator(
            ConfigurationService configurationService) {
        return new DiscoveryClientRouteDefinitionLocator(
                discovery,
                discoveryProperties,
                configurationService);
    }
 
    @Bean
    public RouteLocator routeLocator(RouteLocatorBuilder builder) {
        return builder.routes()
                .route("path_route", r -> r.path("/get")
                        .filters(f -> f.addResponseHeader("Hello", "World"))
                        .uri("http://localhost:8080"))
                .build();
    }
}

这个代码示例展示了如何在Spring Cloud Gateway中使用Kubernetes作为服务发现的方式来定义路由。它创建了一个名为DiscoveryClientRouteDefinitionLocator的Bean，该Bean使用KubernetesDiscoveryClient和KubernetesDiscoveryProperties来自动从Kubernetes服务列表中生成路由信息。同时，它还定义了一个简单的路由，将路径为/get的请求转发到本地的8080端口，并通过过滤器添加了一个响应头。