Add hints for HealthContributors

[olivierboudet]

Add hints for all HealthIndicator subclasses to fix #1183

[sdeleuze]

@bclozel @snicoll Do you think this is something we could be able to infer?

[snicoll]

Yes.

@olivierboudet thanks for the PR! Are you interested if I guide you to repurpose this PR with the AOT engine instead?

[olivierboudet]

@snicoll yes sure.
In fact, at first I tried to use TypeSystem to find classes implementing HealthIndicator but it seems TypeSystem inspects only applications classes and not libraries classes.

This is what I've tried :

public class HealthContributorHints implements NativeConfiguration {

    @Override
    public List<HintDeclaration> computeHints(TypeSystem typeSystem) {
        Type healthIndicator = typeSystem.resolve("org/springframework/boot/actuate/health/HealthIndicator", true);
        if (healthIndicator != null) {
            List<Type> healthIndicatorSubTypes = healthIndicator.getSubtypes();
            HintDeclaration hintDeclaration = new HintDeclaration();
            for (Type subtype: healthIndicatorSubTypes) {
                hintDeclaration.addDependantType(subtype.getDottedName(), new AccessDescriptor(AccessBits.FULL_REFLECTION));
            }
            return Collections.singletonList(hintDeclaration);
        }
        return Collections.emptyList();
    }
}

But healthIndicatorSubTypes is always empty.

I am listening to your advices to update this PR :)

[snicoll]

OK cool. So the idea would be to create a HealthIndicatorNativeConfigurationProcessor class that implements BeanFactoryNativeConfigurationProcessor in the org.springframework.boot.actuate.health package of spring-aot.

That interface gives you access to the bean factory and configuration registry. You could, in the implementation, use beanFactory#getBeanNamesForType(HealthIndicator.class) to retrieve the bean definitions candidate. Then, based on the list, you could feed the registry. As far as I can see, only the constructor is required so you could use the appropriate flag to narrow down the list of reflective configuration (Flag.allDeclaredConstructors).

For testing, please check EndpointNativeConfigurationProcessorTests that shows how you can kick off a simple bean factory and assert that the native configuration registry is in the right state.

You need to register your implementation in spring.factories and then give it a try on your sample. Let me know how it goes!

[olivierboudet]

hello @snicoll I pushed a first try to infer health indicators but only DiskSpaceHealthIndicator and PingHealthIndicator seems to be registered in the bean factory.
I think DiskSpaceHealthIndicator is registered because there is a TypeHintin EndpointAutoConfigurationHints.
However I don't know why PingHealthIndicator is registered but not other indicators like MongoHealthIndicator.

Am I doing something wrong ?

[snicoll]

Am I doing something wrong ?

Nothing that I could see from the code. These two indicators are usually exposed by default. Do you have mongo in the app you're trying and is it configured? If you don't, that's to be expected that it's not available (and therefore not registered for the app).

[olivierboudet]

Yes I have an application with implementation 'org.springframework.boot:spring-boot-starter-data-mongodb'. If I run it with ./gradlew bootRun I can see the mongodb status in /actuator/health
If I build it with ./gradlew bootBuildImage --debug and run it I have the same error as described in the issue :

Native reflection configuration for org.springframework.boot.actuate.mongo.MongoHealthIndicator.<init>(org.springframework.data.mongodb.core.MongoTemplate) is missing.

I think this is because the health indicator for mongodb is in fact a HealthContributor defined by MongoHealthContributorAutoConfiguration.
If I change my BeanFactoryNativeConfigurationProcessor to get all HealthContributor beans, the mongoHealthContributor is found. But in this case, I have another error on the instanciation of MongoDatabaseFactoryDependentConfiguration :

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mongoHealthContributor' defined in class path resource [org/springframework/boot/actuate/autoconfigure/mongo/MongoHealthContributorAutoConfiguration.class]: Unsatisfied dependency expressed through method 'mongoHealthContributor' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.data.mongo.MongoDatabaseFactoryDependentConfiguration': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.data.mongo.MongoDatabaseFactoryDependentConfiguration]: No default constructor found; nested exception is java.lang.NoSuchMethodException: org.springframework.boot.autoconfigure.data.mongo.MongoDatabaseFactoryDependentConfiguration.<init>()
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:800)
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:541)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542)
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:213)
        at org.springframework.boot.actuate.endpoint.annotation.HealthIndicatorNativeConfigurationProcessor.process(HealthIndicatorNativeConfigurationProcessor.java:27)
        at org.springframework.aot.context.bootstrap.generator.infrastructure.nativex.NativeConfigurationRegistrar.lambda$processBeanFactory$0(NativeConfigurationRegistrar.java:55)
        at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
        at org.springframework.aot.context.bootstrap.generator.infrastructure.nativex.NativeConfigurationRegistrar.processBeanFactory(NativeConfigurationRegistrar.java:55)
        at org.springframework.aot.context.bootstrap.generator.ContextBootstrapGenerator.generateBootstrapMethod(ContextBootstrapGenerator.java:92)
        at org.springframework.aot.context.bootstrap.generator.ContextBootstrapGenerator.generateBootstrapClass(ContextBootstrapGenerator.java:79)
        at org.springframework.aot.context.bootstrap.ContextBootstrapContributor.contribute(ContextBootstrapContributor.java:80)
        at org.springframework.aot.BootstrapCodeGenerator.generate(BootstrapCodeGenerator.java:90)
        at org.springframework.aot.BootstrapCodeGenerator.generate(BootstrapCodeGenerator.java:70)
        at org.springframework.aot.context.bootstrap.GenerateBootstrap.call(GenerateBootstrap.java:105)
        at org.springframework.aot.context.bootstrap.GenerateBootstrap.call(GenerateBootstrap.java:44)
        at picocli.CommandLine.executeUserObject(CommandLine.java:1953)
        at picocli.CommandLine.access$1300(CommandLine.java:145)
        at picocli.CommandLine$RunLast.executeUserObjectOfLastSubcommandWithSameParent(CommandLine.java:2352)
        at picocli.CommandLine$RunLast.handle(CommandLine.java:2346)
        at picocli.CommandLine$RunLast.handle(CommandLine.java:2311)
        at picocli.CommandLine$AbstractParseResultHandler.execute(CommandLine.java:2179)
        at picocli.CommandLine.execute(CommandLine.java:2078)
        at org.springframework.aot.context.bootstrap.GenerateBootstrap.main(GenerateBootstrap.java:110)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.data.mongo.MongoDatabaseFactoryDependentConfiguration': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.data.mongo.MongoDatabaseFactoryDependentConfiguration]: No default constructor found; nested exception is java.lang.NoSuchMethodException: org.springframework.boot.autoconfigure.data.mongo.MongoDatabaseFactoryDependentConfiguration.<init>()
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1334)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1232)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542)
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:410)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542)
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
        at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.addCandidateEntry(DefaultListableBeanFactory.java:1598)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1562)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveMultipleBeans(DefaultListableBeanFactory.java:1481)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1338)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300)
        at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:887)
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:791)
        ... 28 more
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.data.mongo.MongoDatabaseFactoryDependentConfiguration]: No default constructor found; nested exception is java.lang.NoSuchMethodException: org.springframework.boot.autoconfigure.data.mongo.MongoDatabaseFactoryDependentConfiguration.<init>()
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:83)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1326)
        ... 52 more
Caused by: java.lang.NoSuchMethodException: org.springframework.boot.autoconfigure.data.mongo.MongoDatabaseFactoryDependentConfiguration.<init>()
        at java.base/java.lang.Class.getConstructor0(Class.java:3349)
        at java.base/java.lang.Class.getDeclaredConstructor(Class.java:2553)
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:78)
        ... 53 more

As MongoDatabaseFactoryDependentConfiguration is not public, I can't set a hint for it.

[snicoll]

I think this is because the health indicator for mongodb is in fact a HealthContributor defined by MongoHealthContributorAutoConfiguration.

Ah yes, sorry. That's what happens when you comment outside of an IDE. You should check for the parent interface indeed (HealthContributor).

But in this case, I have another error on the instanciation of

That's a separate problem. Can you please create an issue for that?

Let me know when the PR is ready with the contributor check or if you want me to take over. Thanks!

[olivierboudet]

The PR is ready with HealthContributor check.
And I opened #1189 for the issue on MongoDatabaseFactoryDependentConfiguration

[snicoll]

@olivierboudet thank you for making your first (code) contribution to Spring Native.