api/volume.go
func volumesList(w http.ResponseWriter, r *http.Request, t auth.Token) error {
	contexts := permission.ContextsForPermission(t, permission.PermVolumeRead)
	if len(contexts) == 0 {
		w.WriteHeader(http.StatusNoContent)
		return nil
	}
	volumes, err := volume.ListByFilter(volumeFilterByContext(contexts))
	if err != nil {
		return err
	}
	if len(volumes) == 0 {
		w.WriteHeader(http.StatusNoContent)
		return nil
	}
	w.Header().Set("Content-Type", "application/json")
	return json.NewEncoder(w).Encode(volumes)
}
func volumesList(w http.ResponseWriter, r *http.Request, t auth.Token) error {
	contexts := permission.ContextsForPermission(t, permission.PermVolumeRead)
	if len(contexts) == 0 {
		w.WriteHeader(http.StatusNoContent)
		return nil
	}
	volumes, err := volume.ListByFilter(volumeFilterByContext(contexts))
	if err != nil {
		return err
	}
	if len(volumes) == 0 {
		w.WriteHeader(http.StatusNoContent)
		return nil
	}
	w.Header().Set("Content-Type", "application/json")
	return json.NewEncoder(w).Encode(volumes)
}
// title: volume list
// path: /volumes
// method: GET
// produce: application/json
// responses:
//   200: List volumes
//   204: No content
//   401: Unauthorized