k8s.io/client-go@v0.31.1/examples/out-of-cluster-client-configuration/main.go (about)

     1  /*
     2  Copyright 2016 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  // Note: the example only works with the code within the same release/branch.
    18  package main
    19  
    20  import (
    21  	"context"
    22  	"flag"
    23  	"fmt"
    24  	"path/filepath"
    25  	"time"
    26  
    27  	"k8s.io/apimachinery/pkg/api/errors"
    28  	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    29  	"k8s.io/client-go/kubernetes"
    30  	"k8s.io/client-go/tools/clientcmd"
    31  	"k8s.io/client-go/util/homedir"
    32  	//
    33  	// Uncomment to load all auth plugins
    34  	// _ "k8s.io/client-go/plugin/pkg/client/auth"
    35  	//
    36  	// Or uncomment to load specific auth plugins
    37  	// _ "k8s.io/client-go/plugin/pkg/client/auth/azure"
    38  	// _ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
    39  	// _ "k8s.io/client-go/plugin/pkg/client/auth/oidc"
    40  )
    41  
    42  func main() {
    43  	var kubeconfig *string
    44  	if home := homedir.HomeDir(); home != "" {
    45  		kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
    46  	} else {
    47  		kubeconfig = flag.String("kubeconfig", "", "absolute path to the kubeconfig file")
    48  	}
    49  	flag.Parse()
    50  
    51  	// use the current context in kubeconfig
    52  	config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
    53  	if err != nil {
    54  		panic(err.Error())
    55  	}
    56  
    57  	// create the clientset
    58  	clientset, err := kubernetes.NewForConfig(config)
    59  	if err != nil {
    60  		panic(err.Error())
    61  	}
    62  	for {
    63  		pods, err := clientset.CoreV1().Pods("").List(context.TODO(), metav1.ListOptions{})
    64  		if err != nil {
    65  			panic(err.Error())
    66  		}
    67  		fmt.Printf("There are %d pods in the cluster\n", len(pods.Items))
    68  
    69  		// Examples for error handling:
    70  		// - Use helper functions like e.g. errors.IsNotFound()
    71  		// - And/or cast to StatusError and use its properties like e.g. ErrStatus.Message
    72  		namespace := "default"
    73  		pod := "example-xxxxx"
    74  		_, err = clientset.CoreV1().Pods(namespace).Get(context.TODO(), pod, metav1.GetOptions{})
    75  		if errors.IsNotFound(err) {
    76  			fmt.Printf("Pod %s in namespace %s not found\n", pod, namespace)
    77  		} else if statusError, isStatus := err.(*errors.StatusError); isStatus {
    78  			fmt.Printf("Error getting pod %s in namespace %s: %v\n",
    79  				pod, namespace, statusError.ErrStatus.Message)
    80  		} else if err != nil {
    81  			panic(err.Error())
    82  		} else {
    83  			fmt.Printf("Found pod %s in namespace %s\n", pod, namespace)
    84  		}
    85  
    86  		time.Sleep(10 * time.Second)
    87  	}
    88  }