Spring boot pass OAuth2 credential to OpenFeign client-CodePudding

I'm having 2 services: service A (spring boot and openfeign for http client) and service B. My services are behind a gateway (APISIX), which is integrated with keycloak. Both services are configured OAuth2 to expose to public.

There is a use case, when a logged in user requests to service A, and service A requests to service B using openfeign. What is the proper way to pass OAuth2 credential to OpenFeign client when requesting to service B?

Thank you very much.

CodePudding user response：

In the case you're on a resource-server and want to issue a request from that resource-server on behalf of the authenticated user, you should be able to access the Bearer token from the Authentication instance in the security-context.

Default Authentication types are JwtAuthenticationToken for resource-servers with JWT decoder and BearerTokenAuthentication for those with introspection.

You can query directly the SecurityContext of the request:

    final AbstractOAuth2TokenAuthenticationToken<? extends AbstractOAuth2Token> auth = (AbstractOAuth2TokenAuthenticationToken) SecurityContextHolder.getContext().getAuthentication();
    final String bearerToken = auth.getToken().getTokenValue();

or have it auto-magically injected as @Controller method parameter:

@RestController
public class MyController {
    @GetMapping("/reflect-bearer-token")
    @PreAuthorize("isAuthenticated()")
    public String reflectBearerToken(AbstractOAuth2TokenAuthenticationToken<? extends AbstractOAuth2Token> auth) {
        return auth.getToken().getTokenValue();
}

First option (querying security-context) can be applied in a a feign RequestInterceptor to add an Authorization header with authenticated user Bearer to every request.