Querying services that sit behind an API gateway

[jwsinner]

I'm trying to migrate REST microservices to using DGS and have been having trouble routing with an API gateway. I guess based on this answer, it seems like this isn't doable, but I figured I'd double check.

Using actuator I'm able to see that the services each have /graphql as an endpoint. I'm using Spring Cloud Gateway so I have a config file that looks like this:

@Bean
open fun routes(builder: RouteLocatorBuilder): RouteLocator{
    return builder.routes()
        .route("user-service"){ it.path("/v1/users/**", "/v1/userinfo/**")
            .uri("http://localhost:3000")
        }
        .route("user-graphql"){ it.path("/userService/graphql")
            .uri("http://localhost:3000/graphql")
        }
        .build()
}

Again, checking on those routes I can see that http://localhost:8080/userService/graphql is pointing to http://localhost:3000/graphql but I'm getting a 404 error in response to trying to query the API gateway endpoint. Is this a "roll your own" scenario or just something that isn't doable with DGS currently?