<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
### 2. endpoint
endpoint 可以帮助你监控应用的信息, 例如，health endpoint 提供基本的应用程序运行状况信息
为了远程调用 endpoint, 你必须通过 http 或者 jmx 去暴露该 endpoint
默认情况下, 你可以使用 http 去访问 /actuator/endpoint-id 来获取该 endpoint 所提供的信息
例如: 你可以访问 /actuator/health 来获取应用的基本进行状况
#### 内置的 endpoint
| ID | Description |
| :----------------- | :----------------------------------------------------------- |
| `auditevents` | Exposes audit events information for the current application. Requires an `AuditEventRepository` bean. |
| `beans` | Displays a complete list of all the Spring beans in your application. |
| `caches` | Exposes available caches. |
| `conditions` | Shows the conditions that were evaluated on configuration and auto-configuration classes and the reasons why they did or did not match. |
| `configprops` | Displays a collated list of all `@ConfigurationProperties`. |
| `env` | Exposes properties from Spring’s `ConfigurableEnvironment`. |
| `flyway` | Shows any Flyway database migrations that have been applied. Requires one or more `Flyway` beans. |
| `health` | Shows application health information. |
| `httptrace` | Displays HTTP trace information (by default, the last 100 HTTP request-response exchanges). Requires an `HttpTraceRepository` bean. |
| `info` | Displays arbitrary application info. |
| `integrationgraph` | Shows the Spring Integration graph. Requires a dependency on `spring-integration-core`. |
| `loggers` | Shows and modifies the configuration of loggers in the application. |
| `liquibase` | Shows any Liquibase database migrations that have been applied. Requires one or more `Liquibase` beans. |
| `metrics` | Shows‘metrics’information for the current application. |
| `mappings` | Displays a collated list of all `@RequestMapping` paths. |
| `scheduledtasks` | Displays the scheduled tasks in your application. |
| `sessions` | Allows retrieval and deletion of user sessions from a Spring Session-backed session store. Requires a Servlet-based web application using Spring Session. |
| `shutdown` | Lets the application be gracefully shutdown. Disabled by default. |
| `threaddump` | Performs a thread dump. |
如果你的应用是 web application (Spring MVC, Spring WebFlux, or Jersey), 以下 endpoint 也是可用的:
| ID | Description |
| :----------- | :----------------------------------------------------------- |
| `heapdump` | Returns an `hprof` heap dump file. |
| `jolokia` | Exposes JMX beans over HTTP (when Jolokia is on the classpath, not available for WebFlux). Requires a dependency on `jolokia-core`. |
| `logfile` | Returns the contents of the logfile (if `logging.file.name` or `logging.file.path` properties have been set). Supports the use of the HTTP `Range` header to retrieve part of the log file’s content. |
| `prometheus` | Exposes metrics in a format that can be scraped by a Prometheus server. Requires a dependency on `micrometer-registry-prometheus`. |
#### 2.1 启用 endpoints
默认的, 除了 shutdown 以外的 endpoint 都是默认启用的, 使用如下配置关闭默认启用的 endpoints, 然后为单独的 endpoint 配置是否启用
```yml
management:
endpoints:
enable-by-default: false
endpoint:
info:
enabled: true
```
`enabled` 选项控制着该 endpoint 是否被创建, 他的相关 bean 是否存在上下文中.
#### 2.2 暴露 endpoints
一些 endpoints 将会暴露敏感的信息, 下表显示了默认情况下内置的 endpoints 的暴露情况
| ID | JMX | Web |
| :----------------- | :--- | :--- |
| `auditevents` | Yes | No |
| `beans` | Yes | No |
| `caches` | Yes | No |
| `conditions` | Yes | No |
| `configprops` | Yes | No |
| `env` | Yes | No |
| `flyway` | Yes | No |
| `health` | Yes | Yes |
| `heapdump` | N/A | No |
| `httptrace` | Yes | No |
| `info` | Yes | Yes |
| `integrationgraph` | Yes | No |
| `jolokia` | N/A | No |
| `logfile` | N/A | No |
| `loggers` | Yes | No |
| `liquibase` | Yes | No |
| `metrics` | Yes | No |
| `mappings` | Yes | No |
| `prometheus` | N/A | No |
| `scheduledtasks` | Yes | No |
| `sessions` | Yes | No |
| `shutdown` | Yes | No |
| `threaddump` | Yes | No |
你可以使用如下配置去选择 endpoint 是否暴露 http 端口或者 jmx:
| Property | Default |
| :------------------------------------------ | :------------- |
| `management.endpoints.jmx.exposure.exclude` | |
| `management.endpoints.jmx.exposure.include` | `*` |
| `management.endpoints.web.exposure.exclude` | |
| `management.endpoints.web.exposure.include` | `info, health` |
`include` 表示需要暴露的 endpoint, exclude 表示不用暴露的, exclude 选项优先于 include 选项, exclude 和 include 都是 list, * 表示所有 endpoint, 在 yml 中 \* 表示特殊用法, 使用 "\*" 代替
for example:
```yml
# 只暴露 health, info 的 jxm
management:
endpoints:
jmx:
exposure:
include: info, health
# 暴露所有除了 info, health 的 web 端口
web:
exposure:
include: "*"
exclude: info, health
```