// Copyright Istio Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package multicluster

import (
	"context"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/client-go/kubernetes"
)

// Use UUID of kube-system Namespace as unique identifier for cluster.
// (see https://docs.google.com/document/d/1F__vEKeI41P7PPUCMM9PVPYY34pyrvQI5rbTJVnS5c4)
func clusterUID(client kubernetes.Interface) (types.UID, error) {
	kubeSystem, err := client.CoreV1().Namespaces().Get(context.TODO(), "kube-system", metav1.GetOptions{})
	if err != nil {
		return "", err
	}
	return kubeSystem.UID, nil
}
