I have tried the new way of customizing the health Actuator in Spring Boot 2.0.0.M5, as described here: https://spring.io/blog/2017/08/22/introducing-actuator-endpoints-in-s
Provide your own @WebEndpoint
like
@Component
@WebEndpoint(id = "acmehealth")
public class AcmeHealthEndpoint {
@ReadOperation
public String hello() {
return "hello health";
}
}
and
via application.properties
:
management.endpoints.web.exposure.include=acmehealth
management.endpoints.web.path-mapping.health=internal/health
management.endpoints.web.path-mapping.acmehealth=/health
This will override /health completely, not just add the information to the existing /health, as a custom HealthIndicator
would. Question is, what you want, because @Endpoint(id = "health")
and "My intention is not to create a custom actuator myhealth, but to customize the existing health actuator" kind of collide. But you can use the existing HealthEndpoint
in your AcmeHealthEndpoint and accomplish both:
@Component
@WebEndpoint(id = "prettyhealth")
public class PrettyHealthEndpoint {
private final HealthEndpoint healthEndpoint;
private final ObjectMapper objectMapper;
@Autowired
public PrettyHealthEndpoint(HealthEndpoint healthEndpoint, ObjectMapper objectMapper) {
this.healthEndpoint = healthEndpoint;
this.objectMapper = objectMapper;
}
@ReadOperation(produces = "application/json")
public String getHealthJson() throws JsonProcessingException {
Health health = healthEndpoint.health();
ObjectWriter writer = objectMapper.writerWithDefaultPrettyPrinter();
return writer.writeValueAsString(health);
}
@ReadOperation
public String prettyHealth() throws JsonProcessingException {
return "<html><body><pre>" + getHealthJson() + "</pre></body></html>";
}
}
The documentation on the new Spring Actuator Endpoints is not very lucid. It's trying to explain the new endpoint infrastructure with the existing health endpoint as an example.
A new endpoint ID has to be unique and shouldn't be same as an existing actuator endpoint. If one tries to the change the ID of the example shown below to health
, one will get the following exception:
java.lang.IllegalStateException: Found two endpoints with the id 'health'
The above comment about declaring the endpoint classes with @Bean
annotation is correct.
Customizing the health
endpoint hasn't changed in Spring Boot 2.0. You still have to implement HealthIndicator
to add custom values.
Here are the changes needed to create a custom Actuator endpoint in Spring Boot 2.0.
The domain containing your custom information.
@Data
@JsonInclude(JsonInclude.Include.NON_EMPTY)
public class MyHealth {
private Map<String, Object> details;
@JsonAnyGetter
public Map<String, Object> getDetails() {
return this.details;
}
}
Declaring myhealth
endpoint,
@Endpoint(id = "myhealth")
public class MyHealthEndpoint {
@ReadOperation
public MyHealth health() {
Map<String, Object> details = new LinkedHashMap<>();
details.put("MyStatus", "is happy");
MyHealth health = new MyHealth();
health.setDetails(details);
return health;
}
}
Extension for myhealth
endpoint,
@WebEndpointExtension(endpoint = MyHealthEndpoint.class)
public class MyHealthWebEndpointExtension {
private final MyHealthEndpoint delegate;
public MyHealthWebEndpointExtension(MyHealthEndpoint delegate) {
this.delegate = delegate;
}
@ReadOperation
public WebEndpointResponse<MyHealth> getHealth() {
MyHealth health = delegate.health();
return new WebEndpointResponse<>(health, 200);
}
}
Configuration to expose the two newly created actuator classes as beans,
@Configuration
public class ActuatorConfiguration {
@Bean
@ConditionalOnMissingBean
@ConditionalOnEnabledEndpoint
public MyHealthEndpoint myHealthEndpoint() {
return new MyHealthEndpoint();
}
@Bean
@ConditionalOnMissingBean
@ConditionalOnEnabledEndpoint
@ConditionalOnBean({MyHealthEndpoint.class})
public MyHealthWebEndpointExtension myHealthWebEndpointExtension(
MyHealthEndpoint delegate) {
return new MyHealthWebEndpointExtension(delegate);
}
}
Changes to application.yml
,
endpoints:
myhealth:
enabled: true
Once you start your application, you should be able to access the newly actuator endpoint at http://<host>:<port>/application/myhealth
.
You should expect a response similar to one shown below,
{
"MyStatus": "is happy"
}
A complete working example can be found here.