// ServerGroups returns the supported groups, with information like supported versions and the
// preferred version.
func (d *DiscoveryClient) ServerGroups() (apiGroupList *unversioned.APIGroupList, err error) {
	// Get the groupVersions exposed at /api
	v := &unversioned.APIVersions{}
	err = d.Get().AbsPath("/api").Do().Into(v)
	apiGroup := unversioned.APIGroup{}
	if err == nil {
		apiGroup = apiVersionsToAPIGroup(v)
	}
	if err != nil && !errors.IsNotFound(err) && !errors.IsForbidden(err) {
		return nil, err
	}

	// Get the groupVersions exposed at /apis
	apiGroupList = &unversioned.APIGroupList{}
	err = d.Get().AbsPath("/apis").Do().Into(apiGroupList)
	if err != nil && !errors.IsNotFound(err) && !errors.IsForbidden(err) {
		return nil, err
	}
	// to be compatible with a v1.0 server, if it's a 403 or 404, ignore and return whatever we got from /api
	if err != nil && (errors.IsNotFound(err) || errors.IsForbidden(err)) {
		apiGroupList = &unversioned.APIGroupList{}
	}

	// append the group retrieved from /api to the list
	apiGroupList.Groups = append(apiGroupList.Groups, apiGroup)
	return apiGroupList, nil
}
// ServerResourcesForGroupVersion returns the supported resources for a group and version.
func (d *DiscoveryClient) ServerResourcesForGroupVersion(groupVersion string) (resources *unversioned.APIResourceList, err error) {
	url := url.URL{}
	if groupVersion == "v1" {
		url.Path = "/api/" + groupVersion
	} else {
		url.Path = "/apis/" + groupVersion
	}
	resources = &unversioned.APIResourceList{}
	err = d.Get().AbsPath(url.String()).Do().Into(resources)
	if err != nil {
		// ignore 403 or 404 error to be compatible with an v1.0 server.
		if groupVersion == "v1" && (errors.IsNotFound(err) || errors.IsForbidden(err)) {
			return resources, nil
		} else {
			return nil, err
		}
	}
	return resources, nil
}