internal/util/restClientGetter.go

// Licensed to Apache Software Foundation (ASF) under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Apache Software Foundation (ASF) licenses this file to you 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 util

import (
	"k8s.io/apimachinery/pkg/api/meta"
	"k8s.io/client-go/discovery"
	"k8s.io/client-go/discovery/cached/memory"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/restmapper"
	"k8s.io/client-go/tools/clientcmd"
)

// SimpleRESTClientGetter implements genericclioptions.RESTClientGetter,
// so that we can use kubectl's functions just by passing kubeConfig and namespace.
type SimpleRESTClientGetter struct {
	Namespace  string
	KubeConfig string
}

func NewSimpleRESTClientGetter(namespace, kubeConfig string) *SimpleRESTClientGetter {
	return &SimpleRESTClientGetter{
		Namespace:  namespace,
		KubeConfig: kubeConfig,
	}
}

func (c *SimpleRESTClientGetter) ToRESTConfig() (*rest.Config, error) {
	config, err := clientcmd.RESTConfigFromKubeConfig([]byte(c.KubeConfig))
	if err != nil {
		return nil, err
	}
	return config, nil
}

func (c *SimpleRESTClientGetter) ToDiscoveryClient() (discovery.CachedDiscoveryInterface, error) {
	config, err := c.ToRESTConfig()
	if err != nil {
		return nil, err
	}

	config.Burst = 100

	discoveryClient, _ := discovery.NewDiscoveryClientForConfig(config)
	return memory.NewMemCacheClient(discoveryClient), nil
}

func (c *SimpleRESTClientGetter) ToRESTMapper() (meta.RESTMapper, error) {
	discoveryClient, err := c.ToDiscoveryClient()
	if err != nil {
		return nil, err
	}

	mapper := restmapper.NewDeferredDiscoveryRESTMapper(discoveryClient)
	expander := restmapper.NewShortcutExpander(mapper, discoveryClient)
	return expander, nil
}

func (c *SimpleRESTClientGetter) ToRawKubeConfigLoader() clientcmd.ClientConfig {
	loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
	loadingRules.DefaultClientConfig = &clientcmd.DefaultClientConfig

	overrides := &clientcmd.ConfigOverrides{ClusterDefaults: clientcmd.ClusterDefaults}
	overrides.Context.Namespace = c.Namespace

	return clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, overrides)
}