By default, all HTTP endpoints are secured such that only users that have an ACTUATOR role may access them. Security is enforced by using the standard HttpServletRequest.isUserInRole method.

	Tip
	If you want to use something other than ACTUATOR as the role, set the management.security.roles property to the value you want to use.

If you deploy applications behind a firewall, you may prefer that all your actuator endpoints can be accessed without requiring authentication. You can do so by changing the management.security.enabled property, as follows:

application.properties. 

management.security.enabled=false

	Caution
	By default, actuator endpoints are exposed on the same port that serves regular HTTP traffic. Take care not to accidentally expose sensitive information if you change the management.security.enabled property.

If you deploy applications publicly, you may want to add ‘Spring Security’ to handle user authentication. When ‘Spring Security’ is added, by default, ‘basic’ authentication is used. The username is`user` and the password is a random generated password (which is printed on the console when the application starts).

	Tip
	Generated passwords are logged as the application starts. To find the password in the console, search for ‘Using default security password’.

You can use Spring properties to change the username and password and to change the security role(s) required to access the endpoints. For example, you might set the following properties in your application.properties:

security.user.name=admin
security.user.password=secret
management.security.roles=SUPERUSER

If your application has custom security configuration and you want all your actuator endpoints to be accessible without authentication, you need to explicitly configure that in your security configuration. Also, you need to change the management.security.enabled property to false.

If your custom security configuration secures your actuator endpoints, you also need to ensure that the authenticated user has the roles specified under management.security.roles.

	Tip
	If you do not have a use case for exposing basic health information to unauthenticated users and you have secured the actuator endpoints with custom security, you can set management.security.enabled to false. This tells Spring Boot to skip the additional role check.

Endpoints can be customized by using Spring properties. You can change whether an endpoint is enabled and its id.

For example, the following application.properties changes the id of the beans endpoint and also enables shutdown:

endpoints.beans.id=springbeans
endpoints.shutdown.enabled=true

	Note
	The prefix ‟endpoints + . + name” is used to uniquely identify the endpoint that is being configured.

By default, all endpoints except for shutdown are enabled. If you prefer to specifically “opt-in” endpoint enablement, you can use the endpoints.default.enabled property. For example, the following settings disables all endpoints except for info:

endpoints.default.enabled=false
endpoints.info.enabled=true

A “discovery page” is added with links to all the endpoints. The “discovery page” is available on /application by default.

When a custom management context path is configured, the “discovery page” automatically moves from /application to the root of the management context. For example, if the management context path is /management, then the discovery page is available from /management. When the management context path is set to /, the discovery page is disabled to prevent the possibility of a clash with other mappings.

Cross-origin resource sharing (CORS) is a W3C specification that allows you to specify in a flexible way what kind of cross domain requests are authorized. If you use Spring MVC or Spring WebFlux, Actuator’s web endpoints can be configured to support such scenarios.

CORS support is disabled by default and is only enabled once the management.endpoints.cors.allowed-origins property has been set. The following configuration permits GET and POST calls from the example.com domain:

management.endpoints.cors.allowed-origins=http://example.com
management.endpoints.cors.allowed-methods=GET,POST

	Tip
	See CorsEndpointProperties for a complete list of options.

If you add a @Bean annotated with @Endpoint, any methods annotated with @ReadOperation or @WriteOperation are automatically exposed over JMX and, in a web application, over HTTP as well.

	Tip
	If you do this as a library feature, consider adding a configuration class annotated with @ManagementContextConfiguration to /META-INF/spring.factories under the key, org.springframework.boot.actuate.autoconfigure.ManagementContextConfiguration. If you do so and if your users ask for a separate management port or address, the endpoint moves to a child context with all the other web endpoints.

You can use health information to check the status of your running application. It is often used by monitoring software to alert someone when a production system goes down. The default information exposed by the health endpoint depends on how it is accessed. For an unauthenticated connection in a secure application, a simple ‘status’ message is returned. For an authenticated connection, additional details are also displayed. (See Section 50.6, “HTTP Health Endpoint Format and Access Restrictions” for HTTP details.)

Health information is collected from all HealthIndicator beans defined in your ApplicationContext. Spring Boot includes a number of auto-configured HealthIndicators, and you can also write your own. By default, the final system state is derived by the HealthAggregator, which sorts the statuses from each HealthIndicator based on an ordered list of statuses. The first status in the sorted list is used as the overall health status. If no HealthIndicator returns a status that is known to the HealthAggregator, an UNKNOWN status is used.

49.6.1 Auto-configured HealthIndicators

The following HealthIndicators are auto-configured by Spring Boot when appropriate:

Name	Description
CassandraHealthIndicator	Checks that a Cassandra database is up.
DiskSpaceHealthIndicator	Checks for low disk space.
DataSourceHealthIndicator	Checks that a connection to DataSource can be obtained.
ElasticsearchHealthIndicator	Checks that an Elasticsearch cluster is up.
JmsHealthIndicator	Checks that a JMS broker is up.
MailHealthIndicator	Checks that a mail server is up.
MongoHealthIndicator	Checks that a Mongo database is up.
RabbitHealthIndicator	Checks that a Rabbit server is up.
RedisHealthIndicator	Checks that a Redis server is up.
SolrHealthIndicator	Checks that a Solr server is up.

	Tip
	It is possible to disable them all using the management.health.defaults.enabled property.

49.6.2 Writing Custom HealthIndicators

To provide custom health information, you can register Spring beans that implement the HealthIndicator interface. You need to provide an implementation of the health() method and return a Health response. The Health response should include a status and can optionally include additional details to be displayed. The following code shows a sample HealthIndicator implementation:

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

@Component
public class MyHealthIndicator implements HealthIndicator {

	@Override
	public Health health() {
		int errorCode = check(); // perform some specific health check
		if (errorCode != 0) {
			return Health.down().withDetail("Error Code", errorCode).build();
		}
		return Health.up().build();
	}

}

	Note
	The identifier for a given HealthIndicator is the name of the bean without the HealthIndicator suffix, if it exists. In the preceding example, the health information is available in an entry named my.

In addition to Spring Boot’s predefined Status types, it is also possible for Health to return a custom Status that represents a new system state. In such cases, a custom implementation of the HealthAggregator interface also needs to be provided, or the default implementation has to be configured by using the management.health.status.order configuration property.

For example, assume a new Status with code FATAL is being used in one of your HealthIndicator implementations. To configure the severity order, add the following to your application properties:

management.health.status.order=FATAL, DOWN, OUT_OF_SERVICE, UNKNOWN, UP

The HTTP status code in the response reflects the overall health status (for example, UP maps to 200, while OUT_OF_SERVICE and DOWN map to 503). You might also want to register custom status mappings if you access the health endpoint over HTTP. For example, the following property maps FATAL to 503 (service unavailable):

management.health.status.http-mapping.FATAL=503

	Tip
	If you need more control, you can define your own HealthStatusHttpMapper bean.

The following table shows the default status mappings for the built-in statuses:

Status	Mapping
DOWN	SERVICE_UNAVAILABLE (503)
OUT_OF_SERVICE	SERVICE_UNAVAILABLE (503)
UP	No mapping by default, so http status is 200
UNKNOWN	No mapping by default, so http status is 200

Application information exposes various information collected from all InfoContributor beans defined in your ApplicationContext. Spring Boot includes a number of auto-configured InfoContributors, and you can write your own.

49.7.1 Auto-configured InfoContributors

The following InfoContributors are auto-configured by Spring Boot, when appropriate:

Name	Description
EnvironmentInfoContributor	Expose any key from the Environment under the info key.
GitInfoContributor	Expose git information if a git.properties file is available.
BuildInfoContributor	Expose build information if a META-INF/build-info.properties file is available.

	Tip
	It is possible to disable them all using the management.info.defaults.enabled property.

49.7.2 Custom Application Information

You can customize the data exposed by the info endpoint by setting info.* Spring properties. All Environment properties under the info key are automatically exposed. For example, you could add the following settings to your application.properties file:

info.app.encoding=UTF-8
info.app.java.source=1.8
info.app.java.target=1.8

	Tip
	Rather than hardcoding those values, you could also expand info properties at build time. Assuming you use Maven, you could rewrite the preceding example as follows: info.app.encoding[email protected]@ info.app.java.source[email protected]@ info.app.java.target[email protected]@

49.7.3 Git Commit Information

Another useful feature of the info endpoint is its ability to publish information about the state of your git source code repository when the project was built. If a GitProperties bean is available, the git.branch, git.commit.id and git.commit.time properties are exposed.

	Tip
	A GitProperties bean is auto-configured if a git.properties file is available at the root of the classpath. See "Generate git information" for more details.

If you want to display the full git information (that is, the full content of git.properties), use the management.info.git.mode property, as follows:

management.info.git.mode=full

49.7.4 Build Information

If a BuildProperties bean is available, the info endpoint can also publish information about your build. This happens if a META-INF/build-info.properties file is available in the classpath.

	Tip
	The Maven and Gradle plugins can both generate that file. See "Generate build information" for more details.

import java.util.Collections;

import org.springframework.boot.actuate.info.Info;
import org.springframework.boot.actuate.info.InfoContributor;
import org.springframework.stereotype.Component;

@Component
public class ExampleInfoContributor implements InfoContributor {

	@Override
	public void contribute(Info.Builder builder) {
		builder.withDetail("example",
				Collections.singletonMap("key", "value"));
	}

}

{
	"example": {
		"key" : "value"
	}
}