Spring Boot Actuator解析 - 文章 - 开发者社区

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    Actuator 是 SpringBoot 项目中一个非常强大一个功能，有助于对应用程序进行监视和管理，通过 Restful Api 请求来监管、审计、收集应用的运行情况。




    Actuator 的核心是端点 Endpoint，它用来监视应用程序及交互，Spring-Boot-Actuator 目前已经内置了非常多的 Endpoint（health、info、beans、metrics、httptrace、shutdown等等），同时也允许我们自己扩展自己的 Endpoints。每个 Endpoint 都可以启用和禁用。要远程访问 Endpoint，还必须通过 JMX 或 HTTP 进行暴露，大部分应用选择HTTP，Endpoint 的ID默认映射到一个带 /actuator 前缀的URL。例如，Health 端点默认映射到 /actuator/health。




  除此，Actuator同时还可以与外部应用监控系统整合，比如 Prometheus, Graphite, DataDog, Influx, Wavefront, New Relic等。这些系统提供了非常好的仪表盘、图标、分析和告警等功能，使得你可以通过统一的接口轻松的监控和管理你的应用。

Actuator使用

   启用Actuator功能，最直接的方式是添加 spring-boot-starter-actuator ‘Starter’依赖




   1、

pom.xml


          
<!-- 2、监控 —— Actuator插件 -->
          
<dependency>
          
    <groupId>org.springframework.boot</groupId>
          
    <artifactId>spring-boot-starter-actuator</artifactId>
          
</dependency>

   2、

application.yml 或application.properties


          
management:
          
  endpoints:
          
    # 暴露 EndPoint 以供访问，有jmx和web两种方式，exclude 的优先级高于 include
          
    jmx:
          
      exposure:
          
        exclude: '*'
          
        include: '*'
          
    web:
          
      exposure:
          
      # exclude: '*'
          
        include: ["health","info","beans","mappings","logfile","metrics","shutdown","env"]
          
      base-path: /actuator  # 配置 Endpoint 的基础路径
          
      cors: # 配置跨域资源共享
          
        allowed-origins: http://example.com
          
        allowed-methods: GET,POST
          
    enabled-by-default: true # 修改全局 endpoint 默认设置
          
  endpoint:
          
    auditevents: # 1、显示当前引用程序的审计事件信息，默认开启
          
      enabled: true
          
      cache:
          
        time-to-live: 10s # 配置端点缓存响应的时间
          
    beans: # 2、显示一个应用中所有 Spring Beans 的完整列表，默认开启
          
      enabled: true
          
    conditions: # 3、显示配置类和自动配置类的状态及它们被应用和未被应用的原因，默认开启
          
      enabled: true
          
    configprops: # 4、显示一个所有@ConfigurationProperties的集合列表，默认开启
          
      enabled: true
          
    env: # 5、显示来自Spring的 ConfigurableEnvironment的属性，默认开启
          
      enabled: true
          
    flyway: # 6、显示数据库迁移路径，如果有的话，默认开启
          
      enabled: true
          
    health: # 7、显示健康信息，默认开启
          
      enabled: true
          
      show-details: always
          
    info: # 8、显示任意的应用信息，默认开启
          
      enabled: true
          
    liquibase: # 9、展示任何Liquibase数据库迁移路径，如果有的话，默认开启
          
      enabled: true
          
    metrics: # 10、展示当前应用的metrics信息，默认开启
          
      enabled: true
          
    mappings: # 11、显示一个所有@RequestMapping路径的集合列表，默认开启
          
      enabled: true
          
    scheduledtasks: # 12、显示应用程序中的计划任务，默认开启
          
      enabled: true
          
    sessions: # 13、允许从Spring会话支持的会话存储中检索和删除(retrieval and deletion)用户会话。使用Spring Session对反应性Web应用程序的支持时不可用。默认开启。
          
      enabled: true
          
    shutdown: # 14、允许应用以优雅的方式关闭，默认关闭
          
      enabled: true
          
    threaddump: # 15、执行一个线程dump
          
      enabled: true
          
    # web 应用时可以使用以下端点
          
    heapdump: # 16、    返回一个GZip压缩的hprof堆dump文件，默认开启
          
      enabled: true
          
    jolokia: # 17、通过HTTP暴露JMX beans（当Jolokia在类路径上时，WebFlux不可用），默认开启
          
      enabled: true
          
    logfile: # 18、返回日志文件内容（如果设置了logging.file或logging.path属性的话），支持使用HTTP Range头接收日志文件内容的部分信息，默认开启
          
      enabled: true
          
    prometheus: #19、以可以被Prometheus服务器抓取的格式显示metrics信息，默认开启
          
      enabled: true

    以简单的项目为例，简要讲解下Actuator功能的相关配置及具体实现，具体如下：

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   构建完项目后进行启动，应用程序默认以端口8080运行，上图表面程序启动正常，可直接通过Uri访问以获取指定暴露的Endpoints。




   通过访问

http://localhost:8080/actuator

来展示所有通过HTTP暴露的Endpoints：


          
[administrator@JavaLangOutOfMemory java ]% curl http://localhost:8080/actuator                                   
          
{"_links":{"self":{"href":"http://localhost:8080/actuator","templated":false},"auditevents":{"href":"http://localhost:8080/actuator/auditevents","templated":false},"beans":{"href":"http://localhost:8080/actuator/beans","templated":false},"caches-cache":{"href":"http://localhost:8080/actuator/caches/{cache}","templated":true},"caches":{"href":"http://localhost:8080/actuator/caches","templated":false},"health-component":{"href":"http://localhost:8080/actuator/health/{component}","templated":true},"health-component-instance":{"href":"http://localhost:8080/actuator/health/{component}/{instance}","templated":true},"health":{"href":"http://localhost:8080/actuator/health","templated":false},"conditions":{"href":"http://localhost:8080/actuator/conditions","templated":false},"shutdown":{"href":"http://localhost:8080/actuator/shutdown","templated":false},"configprops":{"href":"http://localhost:8080/actuator/configprops","templated":false},"env":{"href":"http://localhost:8080/actuator/env","templated":false},"env-toMatch":{"href":"http://localhost:8080/actuator/env/{toMatch}","templated":true},"info":{"href":"http://localhost:8080/actuator/info","templated":false},"loggers":{"href":"http://localhost:8080/actuator/loggers","templated":false},"loggers-name":{"href":"http://localhost:8080/actuator/loggers/{name}","templated":true},"heapdump":{"href":"http://localhost:8080/actuator/heapdump","templated":false},"threaddump":{"href":"http://localhost:8080/actuator/threaddump","templated":false},"metrics":{"href":"http://localhost:8080/actuator/metrics","templated":false},"metrics-requiredMetricName":{"href":"http://localhost:8080/actuator/metrics/{requiredMetricName}","templated":true},"scheduledtasks":{"href":"http://localhost:8080/actuator/scheduledtasks","templated":false},"httptrace":{"href":"http://localhost:8080/actuator/httptrace","templated":false},"mappings":{"href":"http://localhost:8080/actuator/mappings","templated":false}}}%

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   打开

http://localhost:8080/actuator/health

，则会显示如下内容：


          
[administrator@JavaLangOutOfMemory java ]% curl http://localhost:8080/actuator/health
          
{"status":"UP","details":{"diskSpace":{"status":"UP","details":{"total":100790001664,"free":94206066688,"threshold":10485760}}}}%

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   请求结果状态若为

UP，表明应用是健康的。如果应用不健康将会显示DOWN,比如与仪表盘的连接异常或者缺水磁盘空间等。

   打开

http://localhost:8080/actuator/metrics

，则会显示如下内容：


          
[administrator@JavaLangOutOfMemory java ]% curl -i http://localhost:8080/actuator/metrics      
          
HTTP/1.1 200
          
Content-Type: application/vnd.spring-boot.actuator.v2+json;charset=UTF-8
          
Transfer-Encoding: chunked
          
Date: Sun, 10 Jan 2021 01:59:29 GMT
          

          
{"names":["jvm.memory.max","jvm.threads.states","process.files.max","jvm.gc.memory.promoted","tomcat.cache.hit","tomcat.servlet.error","system.load.average.1m","tomcat.cache.access","jvm.memory.used","jvm.gc.max.data.size","jvm.gc.pause","jvm.memory.committed","system.cpu.count","logback.events","http.server.requests","tomcat.global.sent","jvm.buffer.memory.used","tomcat.sessions.created","jvm.threads.daemon","system.cpu.usage","jvm.gc.memory.allocated","tomcat.global.request.max","tomcat.global.request","tomcat.sessions.expired","jvm.threads.live","jvm.threads.peak","tomcat.global.received","process.uptime","tomcat.sessions.rejected","process.cpu.usage","tomcat.threads.config.max","jvm.classes.loaded","jvm.classes.unloaded","tomcat.global.error","tomcat.sessions.active.current","tomcat.sessions.alive.max","jvm.gc.live.data.size","tomcat.servlet.request.max","tomcat.threads.current","tomcat.servlet.request","process.files.open","jvm.buffer.count","jvm.buffer.total.capacity","tomcat.sessions.active.max","tomcat.threads.busy","process.start.time"]}%

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   以下整理了一些非常有用的Actuator Endpoints列表。完整的可以在

official documentation 上面获取。


Endpoint ID	Description
auditevents	显示应用暴露的审计事件 (比如认证进入、订单失败)

info
显示应用的基本信息

health

| 显示和修改配置的loggers | | logfile

| 返回log file中的内容(如果logging.file或者logging.path被设置) | | httptrace

| 显示数据库迁移路径的详细信息 |



liquidbase

heapdump | 执行一个线程dump

返回一个GZip压缩的JVM堆dump |

Actuator Endpoint解析

    /health endpoint




    Health Endpoint通过合并几个健康指数检查应用的健康情况。




    Spring Boot Actuator有几个预定义的健康指标比如DataSourceHealthIndicator, DiskSpaceHealthIndicator, MongoHealthIndicator, RedisHealthIndicator, CassandraHealthIndicator等。它使用这些健康指标作为健康检查的一部分。




    打个比方，如果你的应用使用Redis，RedisHealthindicator将被当作检查的一部分。如果使用MongoDB，那么MongoHealthIndicator将被当作检查的一部分。

你也可以关闭特定的健康检查指标，比如在properties或yml文件中使用如下命令：


        
            

          management.health.redis.enabled=false

Health Endpoint只展示了简单的UP和DOWN状态。为了获得健康检查中所有指标的详细信息，可以通过在application.yaml中增加如下内容：


          
management:
          
  endpoint:
          
    health:
          
      show-details: always

   当然，如果觉得自带的不能够满足我们的实际业务场景，可以通过实现HealthIndicator接口来自定义一个健康指标，或者继承AbstractHealthIndicator类。具体如下：


          
package com.example.actuator.health;
          

          
import org.springframework.boot.actuate.health.AbstractHealthIndicator;
          
import org.springframework.boot.actuate.health.Health;
          
import org.springframework.stereotype.Component;
          

          
@Component
          
public class CustomHealthIndicator extends AbstractHealthIndicator {
          

          
    @Override
          
    protected void doHealthCheck(Health.Builder builder) throws Exception {
          
        // Use the builder to build the health status details that should be reported.
          
        // If you throw an exception, the status will be DOWN with the exception message.
          
        
          
        builder.up()
          
                .withDetail("app", "Alive and Kicking")
          
                .withDetail("error", "No！");
          
    }
          
}

    一旦你增加上面的健康指标到你的应用中去后，Health Endpoint将展示如下细节:


          
{
          
   "status":"UP",
          
   "details":{
          
      "custom":{
          
         "status":"UP",
          
         "details":{
          
            "app":"Alive and Kicking",
          
            "error":"No！"
          
         }
          
      },
          
      "diskSpace":{
          
         "status":"UP",
          
         "details":{
          
            "total":250790436864,
          
            "free":97949245440,
          
            "threshold":10485760
          
         }
          
      }
          
   }
          
}

Spring Security引入

    Actuator Eendpoints是敏感的，必须对其安全性进行可控。如果Spring Security是包含在你的应用中，那么Endpoint是通过HTTP认证被保护起来。

如果没有，可以增加以下依赖到应用中：


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

   通过以下示例简要展示一个简单的Spring Securiy配置。它借助EndPointRequest

的ReqeustMatcher工厂模式来配置Actuator Endpoints进入规则。具体如下：


          
package com.example.actuator.config;
          

          
import org.springframework.boot.actuate.autoconfigure.security.servlet.EndpointRequest;
          
import org.springframework.boot.actuate.context.ShutdownEndpoint;
          
import org.springframework.boot.autoconfigure.security.servlet.PathRequest;
          
import org.springframework.context.annotation.Configuration;
          
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
          
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
          

          
@Configuration
          
public class ActuatorSecurityConfig extends WebSecurityConfigurerAdapter {
          

          
    /*
          
        This spring security configuration does the following
          

          
        1. Restrict access to the Shutdown endpoint to the ACTUATOR_ADMIN role.
          
        2. Allow access to all other actuator endpoints.
          
        3. Allow access to static resources.
          
        4. Allow access to the home page (/).
          
        5. All other requests need to be authenticated.
          
        5. Enable http basic authentication to make the configuration complete.
          
           You are free to use any other form of authentication.
          
     */
          

          
    @Override
          
    protected void configure(HttpSecurity http) throws Exception {
          
        http
          
                .authorizeRequests()
          
                    .requestMatchers(EndpointRequest.to(ShutdownEndpoint.class))
          
                        .hasRole("ACTUATOR_ADMIN")
          
                    .requestMatchers(EndpointRequest.toAnyEndpoint())
          
                        .permitAll()
          
                    .requestMatchers(PathRequest.toStaticResources().atCommonLocations())
          
                        .permitAll()
          
                    .antMatchers("/")
          
                        .permitAll()
          
                    .antMatchers("/**")
          
                        .authenticated()
          
                .and()
          
                .httpBasic();
          
    }
          
}

    然后在application.yaml文件中定义Spring Security用户，具体如下：


          
# Spring Security Default user name and password
          
spring:
          
  security:
          
    user:
          
      name: actuator
          
      password: actuator
          
      roles: ACTUATOR_ADMIN

至此，Actuator监控功能的讲解到此为止，若您在使用过程中有任何的想法或建议，欢迎留言进行技术交流。