Spring Boot 2.6 regression: How can I fix Keycloak circular dependency in adapter?

Question

Spring Boot 2.6.x seems to have introduced some change causing the previously-working integration with Keycloak to have a circular reference, preventing application start; it works and starts fine with the current 2.5.x release.

Explicitly, by changing nothing except the <version> tag value from 2.5.7 to 2.6.1 in spring-boot-starter-parent, the errors/message detailed below occur.

The expected behavior, of course, is that the application starts just fine and is secured with Keycloak just as before.

The actual message is:

***************************
APPLICATION FAILED TO START
***************************

Description:

The dependencies of some of the beans in the application context form a cycle:

┌──->──┐
|  keycloakSecurityConfig (field private org.keycloak.adapters.KeycloakConfigResolver org.keycloak.adapters.springsecurity.config.KeycloakWebSecurityConfigurerAdapter.keycloakConfigResolver)
└──<-──┘

Full stack trace:

2021-11-30 12:49:07.308 DEBUG 7 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : Application failed to start due to an exception

org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'keycloakSecurityConfig': Requested bean is currently in creation: Is there an unresolvable circular reference?        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.beforeSingletonCreation(DefaultSingletonBeanRegistry.java:355) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:227) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:410) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1380) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:656) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:639) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1431) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:619) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:410) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:213) ~[spring-beans-5.3.13.jar!/:5.3.13]
        at org.springframework.boot.web.servlet.ServletContextInitializerBeans.getOrderedBeansOfType(ServletContextInitializerBeans.java:212) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addAsRegistrationBean(ServletContextInitializerBeans.java:175) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addAsRegistrationBean(ServletContextInitializerBeans.java:170) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addAdaptableBeans(ServletContextInitializerBeans.java:155) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.web.servlet.ServletContextInitializerBeans.<init>(ServletContextInitializerBeans.java:87) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.getServletContextInitializerBeans(ServletWebServerApplicationContext.java:260) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.selfInitialize(ServletWebServerApplicationContext.java:234) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.web.embedded.tomcat.TomcatStarter.onStartup(TomcatStarter.java:53) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5219) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[?:?]
        at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[?:?]
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:835) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[?:?]
        at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[?:?]
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:927) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) ~[tomcat-embed-core-9.0.55.jar!/:?]
        at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:473) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:206) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) ~[spring-context-5.3.13.jar!/:5.3.13]
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:730) [spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:412) [spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) [spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) [spring-boot-2.6.1.jar!/:2.6.1]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1290) [spring-boot-2.6.1.jar!/:2.6.1]
        at REDACTED.SpringPortalApplication.main(SpringPortalApplication.java:17) [classes!/:2.0.0]
        at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
        at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?]
        at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
        at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
        at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:49) [spring-portal.jar:2.0.0]
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:108) [spring-portal.jar:2.0.0]
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:58) [spring-portal.jar:2.0.0]
        at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:88) [spring-portal.jar:2.0.0]

2021-11-30 12:49:07.315 ERROR 7 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   :

***************************
APPLICATION FAILED TO START
***************************

Description:

The dependencies of some of the beans in the application context form a cycle:

┌──->──┐
|  keycloakSecurityConfig (field private org.keycloak.adapters.KeycloakConfigResolver org.keycloak.adapters.springsecurity.config.KeycloakWebSecurityConfigurerAdapter.keycloakConfigResolver)
└──<-──┘


Action:

Relying upon circular references is discouraged and they are prohibited by default. Update your application to remove the dependency cycle between beans. As a last resort, it may be possible to break the cycle automatically by setting spring.main.allow-circular-references to true.

The POM is extensive in that it contains lots of spring-boot-starter-... (web,security) entries, along with other uninteresting project dependencies. What I think might be relevant to this particular problem is Keycloak-related things:

In <dependencyManagement>:

• org.keycloak.bom:keycloak-adapter-bom:15.0.2 (version pinned via POM variable)

And as <dependency> entries (versions expected from spring-boot-starter-parent or the Keycloak BOM):

• org.springframework.boot:spring-boot-starter-security
• org.keycloak:keycloak-spring-boot-starter

The only related configuration class present is (Javadoc removed for brevity):

@Configuration
@EnableWebSecurity
@ComponentScan(basePackageClasses = KeycloakSecurityComponents.class)
public class KeycloakSecurityConfig extends KeycloakWebSecurityConfigurerAdapter {

    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth) {
        KeycloakAuthenticationProvider kap = keycloakAuthenticationProvider();
        kap.setGrantedAuthoritiesMapper(new SimpleAuthorityMapper());
        auth.authenticationProvider(kap);
    }

    @Bean
    public KeycloakSpringBootConfigResolver keycloakConfigResolver() {
        return new KeycloakSpringBootConfigResolver();
    }

    @Bean
    @Override
    protected SessionAuthenticationStrategy sessionAuthenticationStrategy() {
        return new RegisterSessionAuthenticationStrategy(new SessionRegistryImpl());
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        super.configure(http);
        http.authorizeRequests()
                .antMatchers("/**")
                .authenticated();
    }

}

I've poked at the Keycloak code a bit and it would seem that abstract o.k.a.s.c.KeycloakWebSecurityConfigurerAdapter, which I extend for the above config class, has an @Autowired(required = false) private field of type o.k.a.KeycloakConfigResolver - exactly what's mentioned in the circular reference error.

I've tried:

• Moving the provider method annotated @Bean returning an implementation of KeycloakConfigResolver (which, in my config class above, is just KeycloakSpringBootConfigResolver) to a different class; resulting in that class being mentioned too in the circular reference error, as an item on the classpath.

• Just removing my provider method that returns KeycloakSpringBootConfigResolver, and seeing if something else is providing it; I realized this doesn't make sense, and it fails as expected since nothing has changed in the Keycloak resources being used here (from 15.0.2) - further, the default method of getting a configuration if the field is null is a JSON file in o.k.a.s.c.KeycloakWebSecurityConfigurerAdapter::adapterDeploymentContext.

• More reading, and now it no longer makes sense to me why what I have actually works - it has a constructor-injected instance of o.k.a.KeycloakConfigResolver, and the provider it has to have been using is a non-static method in itself - which implies that an instance would've had to have been constructed. Per the previous bullet point, commenting out my method that provides the implementation of o.k.a.KeycloakConfigResolver results in it defaulting to the injected-field-is-null condition of trying for the JSON file.

Possibly related, but unsure; doesn't seem to be: very recent question here Spring boot keycloak circular reference

Answer 1

allowing the circular dependencies might not be the best option.

One thing that you can do is to create a specific configuration class for your KeycloakConfigResolver bean.

package com.stackoverflow;

import org.keycloak.adapters.springboot.KeycloakSpringBootConfigResolver;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class KeycloakConfiguration {

    @Bean
    public KeycloakSpringBootConfigResolver KeycloakConfigResolver() {
        return new KeycloakSpringBootConfigResolver();
    }
}