上述pom文件中有以下几点需要注意：
第一、 依赖spring-cloud-kubernetes-core和spring-cloud-kubernetes-discovery，这样能用到spring-cloud-kubernetes提供的服务发现能力；
第二、依赖spring-cloud-starter-gateway，这样能用上SpringCloud的gateway能力；
第三、不要依赖spring-boot-starter-web，会和spring-cloud-starter-gateway冲突，启动时抛出以下异常：
2019-07-06 08:12:09.188 WARN 1 --- [
main] ConfigServletWebServerApplicationContext :
Exception encountered during context initialization -
cancelling refresh attempt:
org.springframework.beans.factory.UnsatisfiedDependencyException:
Error creating bean with name 'routeDefinitionRouteLocator' defined in class path resource [org/springframework/cloud/gateway/config/GatewayAutoConfiguration.class]:
Unsatisfied dependency expressed through method 'routeDefinitionRouteLocator' parameter 1;
nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException:
Error creating bean with name 'modifyRequestBodyGatewayFilterFactory' defined in class path resource [org/springframework/cloud/gateway/config/GatewayAutoConfiguration.class]:
Unsatisfied dependency expressed through method 'modifyRequestBodyGatewayFilterFactory' parameter 0;
nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'org.springframework.http.codec.ServerCodecConfigurer' available:
expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}
开发SpringCloud Gateway的启动类K8sgatewaydemoApplication.java，里面也包含了网关路由配置的实例化，除了配置路径和转发服务的关系，还在请求的header中添加了extendtag属性，请注意注释的内容：
@SpringBootApplication
@EnableDiscoveryClient
public class K8sgatewaydemoApplication {
public static void main(String[] args) {
SpringApplication.run(K8sgatewaydemoApplication.class, args);
}
@Bean
public RouteLocator customRouteLocator(RouteLocatorBuilder builder) {
return builder.routes()
//增加一个path匹配，以"/customize/hello/"开头的请求都在此路由
.route(r -> r.path("/customize/hello/**")
//表示将路径中的第一级参数删除，用剩下的路径与webdemo的路径做拼接，
//这里就是"lb://webdemo/hello/"，能匹配到webdemo的HelloController的路径
.filters(f -> f.stripPrefix(1)
//在请求的header中添加一个key&value
.addRequestHeader("extendtag", "geteway-" + System.currentTimeMillis()))
//指定匹配服务webdemo，lb是load balance的意思
.uri("lb://webdemo")
).build();
}
}
