K8S下SpringCloud应用无损下线

废话不多说直接上代码，一种2个步骤

步骤一： 添加以下代码到SpringCloud应用中

import cn.hutool.extra.spring.SpringUtil;
import com.alibaba.cloud.nacos.registry.NacosAutoServiceRegistration;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;/*** 使用了nacos注册中心的服务关闭端点配置*/
@ConditionalOnClass(NacosAutoServiceRegistration.class)
@RestController
@RequestMapping("actuator")
@RequiredArgsConstructor
@Slf4j
public class NacosStopEndpoint {private final NacosAutoServiceRegistration nacosAutoServiceRegistration;/*** 注销服务后关闭应用前等待的时间(毫秒)*/private int waitTime = 30000;/*** 关闭服务 <br>* 只接收localhost发起的请求** @param request* @return*/@PostMapping("stopService")public ResponseEntity<Boolean> stopNacosService(HttpServletRequest request) throws UnknownHostException {if (!request.getRemoteHost().equalsIgnoreCase("127.0.0.1")) {log.warn("非法访问 尝试关闭应用 远程地址[{}]", request.getRemoteHost());return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body(false);//非本机访问直接return 防止外部攻击}new Thread(() -> {log.info("Nacos instance has been de-registered");nacosAutoServiceRegistration.stop();log.info("Waiting {} milliseconds...", waitTime);try {Thread.sleep(waitTime);} catch (InterruptedException e) {log.info(Thread.currentThread().getName() + " interrupted!", e);}log.info("Spring close……");((ConfigurableApplicationContext) SpringUtil.getApplicationContext()).close();log.info("Spring closed……");System.exit(0);}, "Application Closed Thread").start();return ResponseEntity.ok(true);}
}

步骤二：

配置K8S的工作负载的preStop函数 ， 如下
 

["curl","-X","POST","http://127.0.0.1:8080/actuator/stopService","&&","sleep","30"]

大功告成！从此以后应用下线再也不会丢流量了！