Support different custom configurations for multiple feign clients with the same name

using @FeignClient in spring currently has one fatal issue, which is demonstrated with this repository. If I got two feign clients, each having it’s own configuration (excluded from component scan), and one of them has an RequestInterceptor, both (and all others, if present) get this interceptor also applied. The repository shows the following experiment to show this:

experiment

We assume some foreign service, serving “foo” entities. You have to be authenticated to access this the foo resource and have a role “USER”. If you have “ADMIN”, you will see different data, as when “USER”.

This behavior is implemented using plain spring boot with spring security in the “producer” service. Additionally it registers to an eureka instance, so some “consumer” service is able to fetch this.

So the consumer service should fetch data from consumer, automatically passing basic auth of “users he know”. While this may not clearly makes sense for real world, something very similar is happening consuming OAuth2 secured resource servers with client credentials grant! So to get the data correctly, we define 2 clients, with individually set up basic auth credentials using feign client configuration.

Since the main application does not use @SpringBootApplication, but @EnableAutoConfiguration, and an exclude filter on @ComponentScan, the two different configuration do not declare the internal beans.

So the expected result of these 2 clients is: the UserFooClient retrieving at least a foo entity with value “user1”, while the AdminFooClients result should contain a “admin1” foo.

To verify, which result is intended, the same test is done using plain old RestTemplate.

consequences

This issue leads towards we can’t really use multiple feign clients in spring boot using the @FeignClient annotation, because as soon one client is using some authorization flow (basic, oauth2), this is applied to all other clients.

[ryanjbaxter]

@xetys Based on @spencergibb’s suggestion you can do something like this to accomplish what you want

        @Autowired
        public FooController(
                ResponseEntityDecoder decoder, SpringEncoder encoder, EurekaClient discoveryClient) {
            InstanceInfo prodSvcInfo =  discoveryClient.getNextServerFromEureka("PROD-SVC", false);
            this.fooClient = Feign.builder()
                    .encoder(encoder)
                    .decoder(decoder)
                     .requestInterceptor(new BasicAuthRequestInterceptor("user", "user"))
                     .target(FooClient.class, prodSvcInfo.getHomePageUrl());
            this.adminClient = Feign.builder()
                    .encoder(encoder)
                    .decoder(decoder)
                     .requestInterceptor(new BasicAuthRequestInterceptor("admin", "admin"))
                     .target(FooClient.class, prodSvcInfo.getHomePageUrl());
        }

You could probably also integrate Ribbon into the situation as well.

[dsyer]

You don’t need all that infrastructure to reproduce this problem. All you need is 2 feign clients with the same name and different configurations (they can’t actually have different configuration because the configuration is keyed on the name).