Simplest @EnableEurekaClient app throws exception with eureka.client.enabled=false

[strelok1]

With Camden.SR2 if @EnableEurekaClient is on, but eureka.client.enabled=false, which is a totally valid use case (for example in a local dev profile when you don't want to connect to Eureka Server), this simple app throws an exception. This used to work in Brixton.

I believe this commit to remove the usage of deprecated constructor is the culprit: 856c471

package com.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
@EnableEurekaClient
public class DemoSpringCloudEurekaBugApplication {

	public class ClassThatUsesLoadbalancer {

		private LoadBalancerClient loadBalancerClient;

		public ClassThatUsesLoadbalancer(LoadBalancerClient loadBalancerClient) {
			this.loadBalancerClient = loadBalancerClient;
		}

		public void doStuff() {
			ServiceInstance serviceInstance = loadBalancerClient.choose("http://host/doStuff");
			if (serviceInstance!=null) {
				System.out.println("cool, there is a service instance, because Eureka discovery is enabled and the service is registered");
			} else {
				System.out.println("Oh no instance, because Eureka is disabled or there is no service matching. But this is ok");
			}
		}
	}

	public static void main(String[] args) {
		ConfigurableApplicationContext applicationContext = SpringApplication.run(DemoSpringCloudEurekaBugApplication.class, args);
		ClassThatUsesLoadbalancer classThatUsesLoadbalancer = applicationContext.getBean(ClassThatUsesLoadbalancer.class);
		classThatUsesLoadbalancer.doStuff();
	}

	@Bean
	ClassThatUsesLoadbalancer classThatUsesLoadbalancer(LoadBalancerClient loadBalancerClient){
		return new ClassThatUsesLoadbalancer(loadBalancerClient);
	}
}

The exception:

Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'ribbonLoadBalancingHttpClient' defined in org.springframework.cloud.netflix.ribbon.RibbonClientConfiguration$HttpClientRibbonConfiguration: Unsatisfied dependency expressed through method 'ribbonLoadBalancingHttpClient' parameter 2; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'ribbonLoadBalancer' defined in org.springframework.cloud.netflix.ribbon.RibbonClientConfiguration: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.netflix.loadbalancer.ILoadBalancer]: Factory method 'ribbonLoadBalancer' threw exception; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.netflix.discovery.EurekaClient' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749)
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:467)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1128)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1022)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:512)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:754)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542)
	at org.springframework.cloud.context.named.NamedContextFactory.createContext(NamedContextFactory.java:110)
	at org.springframework.cloud.context.named.NamedContextFactory.getContext(NamedContextFactory.java:79)
	at org.springframework.cloud.context.named.NamedContextFactory.getInstance(NamedContextFactory.java:115)
	at org.springframework.cloud.netflix.ribbon.SpringClientFactory.getInstance(SpringClientFactory.java:111)
	at org.springframework.cloud.netflix.ribbon.SpringClientFactory.getLoadBalancer(SpringClientFactory.java:57)
	at org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.getLoadBalancer(RibbonLoadBalancerClient.java:141)
	at org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.getServer(RibbonLoadBalancerClient.java:130)
	at org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.choose(RibbonLoadBalancerClient.java:62)
	at com.example.DemoSpringCloudEurekaBugApplication$ClassThatUsesLoadbalancer.doStuff(DemoSpringCloudEurekaBugApplication.java:24)

[strelok1]

After a bit of debugging and looking through the available properties on EurekaClientConfigBean
Looks like the only way to get the same behaviour as before is to remove eureka.client.enabled=false
and instead specify:

eureka.client.register-with-eureka=false
eureka.client.fetch-registry=false

This way the instance of a CloudEurekaClient is created and the LoadBalancerClient behaves the same way but does not connect to registry.

I still think it should not throw that exception when eureka.client.enabled=false.

[spencergibb]

Camden fix here d1f8c03

[arindac]

I was getting below exception:

org.springframework.beans.factory.BeanCreationNotAllowedException: Error creating bean with name 'org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration$RefreshableEurekaClientConfiguration': Singleton bean creation not allowed while singletons of this factory are in destruction (Do not request a bean from a BeanFactory in a destroy method implementation!)

Then in application.properties file I added below mentioned property and it worked for me. Thanks @strelok1 for the hint.
eureka.client.enabled=false

[spencergibb]

@arindac please don't comment on closed issues. This fixed the use of the property you mentioned, it wasn't a hint.