Spring Cloud Feign with OAuth2RestTemplate

Question

I'm trying to implement Feign Clients to get my user info from the user's service, currently I'm requesting with oAuth2RestTemplate, it works. But now I wish to change to Feign, but I'm getting error code 401 probably because it doesn't carry the user tokens, so there is a way to customize, if Spring support for Feign is using, a RestTemplate so I can use my own Bean?

Today I'm implementing in this way

The service the client

@Retryable({RestClientException.class, TimeoutException.class, InterruptedException.class})
@HystrixCommand(fallbackMethod = "getFallback")
public Promise<ResponseEntity<UserProtos.User>> get() {
    logger.debug("Requiring discovery of user");
    Promise<ResponseEntity<UserProtos.User>> promise = Broadcaster.<ResponseEntity<UserProtos.User>>create(reactorEnv, DISPATCHER)
            .observe(Promises::success)
            .observeError(Exception.class, (o, e) -> Promises.error(reactorEnv, ERROR_DISPATCHER, e))
            .filter(entity -> entity.getStatusCode().is2xxSuccessful())
            .next();
    promise.onNext(this.client.getUserInfo());
    return promise;

}

And the client

@FeignClient("account")
public interface UserInfoClient {

    @RequestMapping(value = "/uaa/user",consumes = MediaTypes.PROTOBUF,method = RequestMethod.GET)
    ResponseEntity<UserProtos.User> getUserInfo();
}

Answer 1

Feign doesn't use a RestTemplate so you'd have to find a different way. If you create a @Bean of type feign.RequestInterceptor it will be applied to all requests, so maybe one of those with an OAuth2RestTemplate in it (just to manage the token acquisition) would be the best option.

Answer 2

this is my solution, just to complement the another answer with the source code, implementing the interface feign.RequestInterceptor

@Bean
public RequestInterceptor requestTokenBearerInterceptor() {
    return new RequestInterceptor() {
        @Override
        public void apply(RequestTemplate requestTemplate) {
            OAuth2AuthenticationDetails details = (OAuth2AuthenticationDetails)
                    SecurityContextHolder.getContext().getAuthentication().getDetails();

            requestTemplate.header("Authorization", "bearer " + details.getTokenValue());
        }
    };
}