Add Exchange option

client/options.go

@@ -65,6 +65,8 @@ type CallOptions struct {
 }
 
 type PublishOptions struct {
+	// Exchange is the routing exchange for the message
+	Exchange string
 	// Other options for implementations of the interface
 	// can be stored in a context
 	Context context.Context
@@ -236,6 +238,13 @@ func DialTimeout(d time.Duration) Option {
 
 // Call Options
 
+// WithExchange sets the exchange to route a message through
+func WithExchange(e string) PublishOption {
+	return func(o *PublishOptions) {
+		o.Exchange = e
+	}
+}
+
 // WithAddress sets the remote address to use rather than using service discovery
 func WithAddress(a string) CallOption {
 	return func(o *CallOptions) {