github.com/argoproj/argo-cd/v2@v2.10.5/util/kube/portforwarder.go (about)

     1  package kube
     2  
     3  import (
     4  	"bytes"
     5  	"context"
     6  	"fmt"
     7  	"net"
     8  	"net/http"
     9  	"os"
    10  
    11  	corev1 "k8s.io/api/core/v1"
    12  	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    13  	"k8s.io/client-go/kubernetes"
    14  	"k8s.io/client-go/tools/clientcmd"
    15  	"k8s.io/client-go/tools/portforward"
    16  	"k8s.io/client-go/transport/spdy"
    17  
    18  	"github.com/argoproj/argo-cd/v2/util/io"
    19  )
    20  
    21  func PortForward(targetPort int, namespace string, overrides *clientcmd.ConfigOverrides, podSelectors ...string) (int, error) {
    22  	loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
    23  	loadingRules.DefaultClientConfig = &clientcmd.DefaultClientConfig
    24  	clientConfig := clientcmd.NewInteractiveDeferredLoadingClientConfig(loadingRules, overrides, os.Stdin)
    25  	config, err := clientConfig.ClientConfig()
    26  	if err != nil {
    27  		return -1, err
    28  	}
    29  
    30  	if namespace == "" {
    31  		namespace, _, err = clientConfig.Namespace()
    32  		if err != nil {
    33  			return -1, err
    34  		}
    35  	}
    36  
    37  	clientSet, err := kubernetes.NewForConfig(config)
    38  	if err != nil {
    39  		return -1, err
    40  	}
    41  
    42  	var pod *corev1.Pod
    43  
    44  	for _, podSelector := range podSelectors {
    45  		pods, err := clientSet.CoreV1().Pods(namespace).List(context.Background(), v1.ListOptions{
    46  			LabelSelector: podSelector,
    47  		})
    48  		if err != nil {
    49  			return -1, err
    50  		}
    51  
    52  		if len(pods.Items) > 0 {
    53  			pod = &pods.Items[0]
    54  			break
    55  		}
    56  	}
    57  
    58  	if pod == nil {
    59  		return -1, fmt.Errorf("cannot find pod with selector: %v - use the --{component}-name flag in this command or set the environmental variable (Refer to https://argo-cd.readthedocs.io/en/stable/user-guide/environment-variables), to change the Argo CD component name in the CLI", podSelectors)
    60  	}
    61  
    62  	url := clientSet.CoreV1().RESTClient().Post().
    63  		Resource("pods").
    64  		Namespace(pod.Namespace).
    65  		Name(pod.Name).
    66  		SubResource("portforward").URL()
    67  
    68  	transport, upgrader, err := spdy.RoundTripperFor(config)
    69  	if err != nil {
    70  		return -1, fmt.Errorf("could not create round tripper: %w", err)
    71  	}
    72  	dialer := spdy.NewDialer(upgrader, &http.Client{Transport: transport}, "POST", url)
    73  
    74  	readyChan := make(chan struct{}, 1)
    75  	failedChan := make(chan error, 1)
    76  	out := new(bytes.Buffer)
    77  	errOut := new(bytes.Buffer)
    78  
    79  	ln, err := net.Listen("tcp", "localhost:0")
    80  	if err != nil {
    81  		return -1, err
    82  	}
    83  	port := ln.Addr().(*net.TCPAddr).Port
    84  	io.Close(ln)
    85  
    86  	forwarder, err := portforward.New(dialer, []string{fmt.Sprintf("%d:%d", port, targetPort)}, context.Background().Done(), readyChan, out, errOut)
    87  	if err != nil {
    88  		return -1, err
    89  	}
    90  
    91  	go func() {
    92  		err = forwarder.ForwardPorts()
    93  		if err != nil {
    94  			failedChan <- err
    95  		}
    96  	}()
    97  	select {
    98  	case err = <-failedChan:
    99  		return -1, err
   100  	case <-readyChan:
   101  	}
   102  	if len(errOut.String()) != 0 {
   103  		return -1, fmt.Errorf(errOut.String())
   104  	}
   105  	return port, nil
   106  }