How to register a spring cloud app to both Eureka

问题:

In spring cloud v1.1, I can use @EnableDiscoveryClient and @EnableEurekaClient to register a spring cloud app to both Eureka and Consul properly, because I want to use circuit breakers of Eureka/Zuul and key-value configurations of consul. But when using spring cloud v1.2.1, for the same code, I got the following exception:

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APPLICATION FAILED TO START
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Description:

Parameter 0 of method serviceRegistryEndpoint in    org.springframework.cloud.client.serviceregistry.ServiceRegistryAutoConfiguration$ServiceRegistryEndpointConfiguration required a single bean, but 2 were found:
    - eurekaServiceRegistry: defined by method 'eurekaServiceRegistry' in class path resource [org/springframework/cloud/netflix/eureka/EurekaClientAutoConfiguration.class]
    - consulServiceRegistry: defined by method 'consulServiceRegistry' in class path resource [org/springframework/cloud/consul/serviceregistry/ConsulServiceRegistryAutoConfiguration.class]


Action:

Consider marking one of the beans as @Primary, updating the consumer to accept multiple beans, or using @Qualifier to identify the bean that should be consumed

I found the class of org.springframework.cloud.client.serviceregistry.ServiceRegistryAutoConfiguration is a new class from spring cloud v1.2.0, and its purpose is

Patterns such as service discovery, load balancing and circuit breakers lend themselves to a common abstraction layer that can be consumed by all Spring Cloud clients, independent of the implementation (e.g. discovery via Eureka or Consul).

So, does it mean using spring cloud v1.2, I could register the app to only consul but could use key-value configurations and circuit breakers?

回答1:

I just did it.

The key is exclude default auto configurations in application.yml like this:

spring.autoconfigure.exclude: - org.springframework.cloud.client.serviceregistry.ServiceRegistryAutoConfiguration - org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationAutoConfiguration

Then you can write your own implementations or just ignore those beans.

see: https://github.com/cloud-ready/spring-cloud-service-discovery/tree/develop/spring-cloud-multi-registration for details.

回答2:

Would it also not be possible to explicitly use the ServiceRegistry interface implementations from each package (eg. see EurekaRegistry) and explicitly register:

class Example:

    @Autowired
    EurekaRegistry eurekaRegistry; 

    @Autowired
    ConsulRegistry consulRegistry;

    void register(Registration registration){
        eurekaRegistry(registration);
        consulRegistry(registration);
     }