minor runtime fixes

runtime/default.go

@@ -155,7 +155,7 @@ func (r *runtime) Create(s *Service, opts ...CreateOption) error {
 	defer r.Unlock()
 
 	if _, ok := r.services[s.Name]; ok {
-		return errors.New("service already registered")
+		return errors.New("service already running")
 	}
 
 	var options CreateOptions

runtime/options.go

@@ -54,6 +54,13 @@ type ReadOptions struct {
 	Type string
 }
 
+// CreateType sets the type of service to create
+func CreateType(t string) CreateOption {
+	return func(o *CreateOptions) {
+		o.Type = t
+	}
+}
+
 // WithCommand specifies the command to execute
 func WithCommand(args ...string) CreateOption {
 	return func(o *CreateOptions) {