使用Spring Boot2.x Actuator監控應用並控制UP/DOWN

SpringCloud的Admin監控組件基於Actuator
Actuator通過服務的心跳向註冊中心（比如Eureka）上報健康狀況

服務添加依賴

	<dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>

默認端點

Spring Boot 2.0 的Actuator只暴露了health和info端點，提供的監控信息無法滿足我們的需求

在1.x中有n多可供我們監控的節點，官方的回答是爲了安全

開啓所有端點

在application.properties中加入如下配置信息

*代表所有節點都加載

#開啓所有端點
management.endpoints.web.exposure.include=*

測試

開啓服務，打開：http://{host}:{port}/actuator

可以看到返回了一串JSON，其中有個health，就是服務的健康狀態，所謂健康狀態，不是說一定服務掛了纔是DOWN，而是可能服務沒掛，但是沒連上MySQL，或者短信發送的量已經達到極限了，這些都有可能需要讓服務狀態變成DOWN

{"_links":{"self":{"href":"http://localhost:81/actuator","templated":false},"archaius":{"href":"http://localhost:81/actuator/archaius","templated":false},"beans":{"href":"http://localhost:81/actuator/beans","templated":false},"caches-cache":{"href":"http://localhost:81/actuator/caches/{cache}","templated":true},"caches":{"href":"http://localhost:81/actuator/caches","templated":false},"health":{"href":"http://localhost:81/actuator/health","templated":false},"health-path":{"href":"http://localhost:81/actuator/health/{*path}","templated":true},"info":{"href":"http://localhost:81/actuator/info","templated":false},"conditions":{"href":"http://localhost:81/actuator/conditions","templated":false},"shutdown":{"href":"http://localhost:81/actuator/shutdown","templated":false},"configprops":{"href":"http://localhost:81/actuator/configprops","templated":false},"env":{"href":"http://localhost:81/actuator/env","templated":false},"env-toMatch":{"href":"http://localhost:81/actuator/env/{toMatch}","templated":true},"loggers":{"href":"http://localhost:81/actuator/loggers","templated":false},"loggers-name":{"href":"http://localhost:81/actuator/loggers/{name}","templated":true},"heapdump":{"href":"http://localhost:81/actuator/heapdump","templated":false},"threaddump":{"href":"http://localhost:81/actuator/threaddump","templated":false},"metrics-requiredMetricName":{"href":"http://localhost:81/actuator/metrics/{requiredMetricName}","templated":true},"metrics":{"href":"http://localhost:81/actuator/metrics","templated":false},"scheduledtasks":{"href":"http://localhost:81/actuator/scheduledtasks","templated":false},"mappings":{"href":"http://localhost:81/actuator/mappings","templated":false},"refresh":{"href":"http://localhost:81/actuator/refresh","templated":false},"features":{"href":"http://localhost:81/actuator/features","templated":false},"service-registry":{"href":"http://localhost:81/actuator/service-registry","templated":false}}}

打開：http://{host}:{port}/actuator/health，頁面顯示如下，證明服務可用

{"status":"UP"}

遠程控制服務開關

在服務的配置文件application.properties加上如下配置

#可以遠程關閉服務節點
management.endpoint.shutdown.enabled=true

添加一個類

package com.bl.eurekaprovider;

import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Service;

/**
 * @Deacription 改變健康狀態的Service
 * @Author BarryLee
 * @Date 2020/6/13 21:30
 */
@Service
public class HealthStatusService implements HealthIndicator {
  private Boolean status = true;

  public void setStatus(Boolean status) {
    this.status = status;
  }

  @Override
  public Health health() {
    if (status) {
      return new Health.Builder().up().build();
    }
    return new Health.Builder().down().build();
  }

  public String getStatus() {
    return this.status.toString();
  }
}

在Controller添加如下代碼

  @Autowired
  private HealthStatusService healthStatusService;
  /**
   * 用來改變當前服務的狀態，測試用
   */
  @GetMapping("/health")
  public String health(@RequestParam("status") Boolean status) {
    // 改變狀態
    healthStatusService.setStatus(status);
    // 返回當前狀態
    return healthStatusService.getStatus();
  }

瀏覽器或者postman訪問：http://{host}:{port}/health?status=false

在Eureka Server中可以看到服務已經下線了，如果想要上線，改爲true，三十秒內就會重新上線，生產商謹慎打開，內網倒是無所謂