api/resolver: update resolver to enable subdomain routing (#1747)

* api/resolver: update domain / service prefix usage

* api/resolver/subdomain: implement subdomain resolver for domain resolution

* api/handler: fix tests

api/resolver/path/path.go

@@ -18,13 +18,13 @@ func (r *Resolver) Resolve(req *http.Request) (*resolver.Endpoint, error) {
 	}
 
 	parts := strings.Split(req.URL.Path[1:], "/")
-	ns := r.opts.Namespace(req)
 
 	return &resolver.Endpoint{
-		Name:   ns + "." + parts[0],
+		Name:   r.opts.ServicePrefix + "." + parts[0],
 		Host:   req.Host,
 		Method: req.Method,
 		Path:   req.URL.Path,
+		Domain: r.opts.Domain,
 	}, nil
 }