Mastering Spring Boot's Actuator with Madhura Bhave at SpringOne Tour 2019

1. Mastering Spring Boot’s Actuator
Madhura Bhave
@madhurabhave23

2. 2
Actuator?

3. 3
actuator
noun
mechanical device for moving or
controlling something
Spring Boot Actuator
noun
module for controlling Spring
Boot applications
Actuator?

4. What’s new?

5. What’s new?
• Endpoints under /actuator
• management.endpoints.web.base-path
• management.endpoints.web.exposure.include
management.endpoints.web.exposure.exclude
• management.endpoint.shutdown.enabled
• management.endpoint.health.show-details
• EndpointRequest
• Jersey, WebFlux, or Spring MVC
5

6. What’s new?
• New endpoints
• ScheduledTasksEndpoint
• SessionsEndpoint
• CachesEndpoint
• IntegrationGraphEndpoint
6

7. 7
{
"status" : "UP",
"details" : {
"db" : {
"status" : "UP",
"details" : {
"database" : "HSQL Database Engine",
"hello" : 1
}
},
"broker" : {
"status" : "UP",
"details" : {
"us1" : {
"status" : "UP",
"details" : {
"version" : "1.0.2"
}
},
"us2" : {
"status" : "UP",
"details" : {
"version" : "1.0.4"
}}}}}}
/actuator/health /{component}
{
"status" : "UP",
"details" : {
"us1" : {
"status" : "UP",
"details" : {
"version" : "1.0.2"
}
},
"us2" : {
"status" : "UP",
"details" : {
"version" : "1.0.4"
}}}}
{
"status" : "UP",
"details" : {
"version" : "1.0.2"
}
}
/{instance}

8. CloudFoundry Integration

9. CloudFoundry Integration
• Endpoints available under /cloudfoundryapplication
• Requires a valid UAA token
• management.cloudfoundry.enabled
• Jersey, WebFlux, or Spring MVC
9

10. Web API documentation

11. Metrics

12. 12

13. Writing your own endpoints

14. 14
/**
* {@link Endpoint} to expose a user's {@link Session}s.
*
* @author Vedran Pavic
* @since 2.0.0
*/
@Endpoint(id = "sessions")
public class SessionsEndpoint {
// …
}
@Endpoint(id = "sessions")
http://example.com/actuator/
sessions

15. 15
@ReadOperation
public SessionsReport sessionsForUsername(String username) {
Map<String, ? extends Session> sessions =
this.sessionRepository.findByIndexNameAndIndexValue(
FindByIndexNameSessionRepository.PRINCIPAL_NAME_INDEX_NAME,
username);
return new SessionsReport(sessions);
}
@ReadOperation
(String username)SessionsReport
GET http://example.com/actuator/sessions
username
? =alice

16. 16
@ReadOperation
public SessionDescriptor getSession(@Selector String sessionId) {
Session session = this.sessionRepository.findById(sessionId);
if (session == null) {
return null;
}
return new SessionDescriptor(session);
}
@ReadOperation
(@Selector String sessionId)SessionDescriptor
GET http://example.com/actuator/sessions
sessionId
/{ }

17. 17
@DeleteOperation
public void deleteSession(@Selector String sessionId) {
this.sessionRepository.deleteById(sessionId);
}
@DeleteOperation
@Selector String sessionId
DELETE http://example.com/actuator/sessions
sessionId
/{ }
void

18. 18
@Endpoint(id = "loggers")
public class LoggersEndpoint {
@WriteOperation
public void configureLogLevel(@Selector String name,
@Nullable LogLevel configuredLevel) {
Assert.notNull(name, "Name must not be empty");
this.loggingSystem.setLogLevel(name, configuredLevel);
}
}
@Endpoint(id = "loggers")
@WriteOperation
void @Selector String name
@Nullable LogLevel configuredLevel
POST http://example.com/actuator/loggers
name
/{ }
{
" ": "DEBUG"
}
configuredLevel

19. Writing your own endpoints
Beyond the basics

20. 20
@EndpointWebExtension(endpoint = HealthEndpoint.class)
public class HealthEndpointWebExtension {
@ReadOperation
public WebEndpointResponse<Health> getHealth(
SecurityContext securityContext) {
return this.responseMapper.map(
this.delegate.health(), securityContext);
}
}
@EndpointWebExtension(endpoint = HealthEndpoint.class)
WebEndpointResponse<Health>
SecurityContext securityContext

21. Thanks!
Madhura Bhave
@madhurabhave23