Add the notion of a node selector for routing

client/options.go

@@ -14,6 +14,7 @@ type options struct {
 	registry    registry.Registry
 	transport   transport.Transport
 	wrappers    []Wrapper
+	selector    NodeSelector
 }
 
 // Broker to be used for pub/sub
@@ -51,6 +52,13 @@ func Transport(t transport.Transport) Option {
 	}
 }
 
+// Selector is used to select a node to route a request to
+func Selector(s NodeSelector) Option {
+	return func(o *options) {
+		o.selector = s
+	}
+}
+
 // Adds a Wrapper to a list of options passed into the client
 func Wrap(w Wrapper) Option {
 	return func(o *options) {