Spring Cloud Zuul Doesn't Relay Access Token - spring-security-oauth2

Question

I am trying to use Spring Cloud Zuul as an api/authentication gateway. I have successfully implemented bearer token authorization for my service behind zuul and I successfully have Zuul forwarding to my form login and routing back to my application, but I cannot get Zuul to pass the bearer token to the service.
My Zuul configuration is as follows:
#EnableEurekaClient
#EnableZuulProxy
#SpringBootApplication
#RestController
public class Application { ... }
My service configuration is as follows:
#Profile("oauth")
#Configuration
#EnableResourceServer
#EnableWebSecurity
public static class InternalApiGatewayConfig extends ResourceServerConfigurerAdapter {
When my Angular app tries to access my service through zuul, I get
{"error":"unauthorized","error_description":"Full authentication is required to access this resource"}
I have managed to work around this issue by putting the following code in a ZuulFilter, but it doesn't seem right:
Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
OAuth2AuthenticationDetails details = (OAuth2AuthenticationDetails)authentication.getDetails();
String tokenValue = details.getTokenValue();
ctx.addZuulRequestHeader("Authorization", "bearer " + tokenValue);
My understanding is that Zuul should automatically send the bearer token value. What am I missing?

Answer 1

So I've figured out the answer to my own question, and it was painfully simple. My project imported spring-security-oauth2. I simply needed to add a dependency on spring-cloud-security as well. With that, I did not have to implement a ZuulFilter at all.

Answer 2

Btw this is the solution that works without spring-cloud-security
#Component
public class TokenRelayFilter extends ZuulFilter {
#Override
public Object run() {
RequestContext ctx = RequestContext.getCurrentContext();
#SuppressWarnings("unchecked")
Set<String> headers = (Set<String>) ctx.get("ignoredHeaders");
// JWT tokens should be relayed to the resource servers
headers.remove("authorization");
return null;
}
#Override
public boolean shouldFilter() {
return true;
}
#Override
public String filterType() {
return "pre";
}
#Override
public int filterOrder() {
return 10000;
}
}