Health Web Endpoint Extension Failed to Initialize When Some Conditions Hit

[leovx]

Dear all,
I just encountered a framework bug, details below. Let's together figure out the most neat way to handle it. :)

Trigger Conditions

0. Running on Cloud Foundry environment
1. Using Spring Boot Actuator 2.6.x (Current latest = 2.6.2)
2. In your config file, manually include some endpoints but not 'health'

Related Issues:

#28389
#25471
#28131

My Project to Replay the Bug and Temp Solution

https://github.com/leovx/spring-boot-actuator-pcf-bug-demo

Error log

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'healthEndpointWebMvcHandlerMapping' defined in class path resource [org/springframework/boot/actuate/autoconfigure/health/HealthEndpointWebExtensionConfiguration$MvcAdditionalHealthEndpointPathsConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.actuate.endpoint.web.servlet.AdditionalHealthEndpointPathsWebMvcHandlerMapping]: Factory method 'healthEndpointWebMvcHandlerMapping' threw exception; nested exception is java.util.NoSuchElementException: No value present
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:658) ~[spring-beans-5.3.14.jar:5.3.14]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:638) ~[spring-beans-5.3.14.jar:5.3.14]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) ~[spring-beans-5.3.14.jar:5.3.14]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-5.3.14.jar:5.3.14]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.14.jar:5.3.14]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.14.jar:5.3.14]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.14.jar:5.3.14]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.14.jar:5.3.14]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.14.jar:5.3.14]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.14.jar:5.3.14]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953) ~[spring-beans-5.3.14.jar:5.3.14]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.14.jar:5.3.14]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.14.jar:5.3.14]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.2.jar:2.6.2]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:730) ~[spring-boot-2.6.2.jar:2.6.2]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:412) ~[spring-boot-2.6.2.jar:2.6.2]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) ~[spring-boot-2.6.2.jar:2.6.2]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) ~[spring-boot-2.6.2.jar:2.6.2]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1290) ~[spring-boot-2.6.2.jar:2.6.2]
    at com.jinghao.demo.DemoApplication.main(DemoApplication.java:10) ~[classes/:na]
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.actuate.endpoint.web.servlet.AdditionalHealthEndpointPathsWebMvcHandlerMapping]: Factory method 'healthEndpointWebMvcHandlerMapping' threw exception; nested exception is java.util.NoSuchElementException: No value present
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.3.14.jar:5.3.14]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653) ~[spring-beans-5.3.14.jar:5.3.14]
    ... 19 common frames omitted
Caused by: java.util.NoSuchElementException: No value present
    at java.base/java.util.Optional.get(Optional.java:143) ~[na:na]
    at org.springframework.boot.actuate.autoconfigure.health.HealthEndpointWebExtensionConfiguration.getHealthEndpoint(HealthEndpointWebExtensionConfiguration.java:81) ~[spring-boot-actuator-autoconfigure-2.6.2.jar:2.6.2]
    at org.springframework.boot.actuate.autoconfigure.health.HealthEndpointWebExtensionConfiguration.access$000(HealthEndpointWebExtensionConfiguration.java:69) ~[spring-boot-actuator-autoconfigure-2.6.2.jar:2.6.2]
    at org.springframework.boot.actuate.autoconfigure.health.HealthEndpointWebExtensionConfiguration$MvcAdditionalHealthEndpointPathsConfiguration.healthEndpointWebMvcHandlerMapping(HealthEndpointWebExtensionConfiguration.java:90) ~[spring-boot-actuator-autoconfigure-2.6.2.jar:2.6.2]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.3.14.jar:5.3.14]
    ... 20 common frames omitted

[leovx]

Spring Boot 2.6.3 has been confirmed to have the bug.

[bclozel]

I've reproduced the issue with the sample provided by @leovx (thanks! that was super useful!).

To summarize: an application that selectively enables web endpoints (but not the health one) in its application.properties and deployed on CloudFoundry fails with the exception above.

What happens is:

The OnAvailableEndpointCondition always matches for a CloudPlatform.CLOUD_FOUNDRY environment. So @ConditionalOnAvailableEndpoint(endpoint = HealthEndpoint.class, exposure = {EndpointExposure.WEB}) on HealthEndpointWebExtensionConfiguration matches in this case.

In the same class, org.springframework.boot.actuate.autoconfigure.health.HealthEndpointWebExtensionConfiguration.MvcAdditionalHealthEndpointPathsConfiguration#healthEndpointWebMvcHandlerMapping fails because the injected WebEndpointsSupplier is an instance of WebEndpointDiscoverer and it does not contain the health endpoint.

All the CloudFoundry setup is done in org.springframework.boot.actuate.autoconfigure.cloudfoundry.servlet.CloudFoundryActuatorAutoConfiguration#cloudFoundryWebEndpointServletHandlerMapping.

The condition should be probably revisited with this use case in mind.

[leovx]

Thanks @bclozel. To add up, some teams might not want to use PCF health, but the vanilla one. Hence they might have below setting set to false, which would disable CloudFoundryActuatorAutoConfiguration during boot up.

management.cloudfoundry.enabled=false

@mbhave Please do let me know what you think about the fix we can do in Spring Boot framework. I am pretty curious about the fix, though not yet have time to read through the whole Actuator codebase.

Appreciated. :D

[izeye]

This seems to belong to the 2.6.4 milestone.