// Copyright 2017 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 controller implements the shared and reusable library for Kubernetes
package controller

import (
	"k8s.io/client-go/kubernetes"
	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp" // import OIDC cluster authentication plugin, e.g. for Tectonic
	_ "k8s.io/client-go/plugin/pkg/client/auth/oidc"
	restclient "k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"
)

// CreateInterface is a helper function to create Kubernetes interface from kubeconfig file
func CreateInterface(kubeconfig string) (kubernetes.Interface, error) {
	if len(kubeconfig) == 0 {
		// Avoid the confusing "Things might not work" message
		restConfig, err := restclient.InClusterConfig()
		if err != nil {
			return nil, err
		}
		return kubernetes.NewForConfig(restConfig)
	}
	restConfig, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
	if err != nil {
		return nil, err
	}
	return kubernetes.NewForConfig(restConfig)
}
