Merge pull request #10844 from afbjorklund/kubectl-ssh

Allow running kubectl over the ssh connection

Author: medyagh

cmd/minikube/cmd/generate-docs.go

@@ -27,7 +27,7 @@ import (
 	"k8s.io/minikube/pkg/minikube/style"
 )
 
-var path string
+var docsPath string
 
 // generateDocs represents the generate-docs command
 var generateDocs = &cobra.Command{
@@ -38,20 +38,20 @@ var generateDocs = &cobra.Command{
 	Hidden:  true,
 	Run: func(cmd *cobra.Command, args []string) {
 		// if directory does not exist
-		docsPath, err := os.Stat(path)
-		if err != nil || !docsPath.IsDir() {
+		st, err := os.Stat(docsPath)
+		if err != nil || !st.IsDir() {
 			exit.Message(reason.Usage, "Unable to generate the documentation. Please ensure that the path specified is a directory, exists & you have permission to write to it.")
 		}
 
 		// generate docs
-		if err := generate.Docs(RootCmd, path); err != nil {
+		if err := generate.Docs(RootCmd, docsPath); err != nil {
 			exit.Error(reason.InternalGenerateDocs, "Unable to generate docs", err)
 		}
-		out.Step(style.Documentation, "Docs have been saved at - {{.path}}", out.V{"path": path})
+		out.Step(style.Documentation, "Docs have been saved at - {{.path}}", out.V{"path": docsPath})
 	},
 }
 
 func init() {
-	generateDocs.Flags().StringVar(&path, "path", "", "The path on the file system where the docs in markdown need to be saved")
+	generateDocs.Flags().StringVar(&docsPath, "path", "", "The path on the file system where the docs in markdown need to be saved")
 	RootCmd.AddCommand(generateDocs)
 }

cmd/minikube/cmd/kubectl.go

@@ -20,14 +20,22 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
+	"path"
 	"syscall"
 
 	"github.com/spf13/cobra"
 	"k8s.io/klog/v2"
 	"k8s.io/minikube/pkg/minikube/config"
 	"k8s.io/minikube/pkg/minikube/constants"
+	"k8s.io/minikube/pkg/minikube/machine"
+	"k8s.io/minikube/pkg/minikube/mustload"
 	"k8s.io/minikube/pkg/minikube/node"
 	"k8s.io/minikube/pkg/minikube/out"
+	"k8s.io/minikube/pkg/minikube/vmpath"
+)
+
+var (
+	useSSH bool
 )
 
 // kubectlCmd represents the kubectl command
@@ -36,9 +44,13 @@ var kubectlCmd = &cobra.Command{
 	Short: "Run a kubectl binary matching the cluster version",
 	Long: `Run the Kubernetes client, download it if necessary. Remember -- after kubectl!
 
-Examples:
-minikube kubectl -- --help
-minikube kubectl -- get pods --namespace kube-system`,
+This will run the Kubernetes client (kubectl) with the same version as the cluster
+
+Normally it will download a binary matching the host operating system and architecture,
+but optionally you can also run it directly on the control plane over the ssh connection.
+This can be useful if you cannot run kubectl locally for some reason, like unsupported
+host. Please be aware that when using --ssh all paths will apply to the remote machine.`,
+	Example: "minikube kubectl -- --help\nminikube kubectl -- get pods --namespace kube-system",
 	Run: func(cmd *cobra.Command, args []string) {
 		cc, err := config.Load(ClusterFlagValue())
 
@@ -47,8 +59,31 @@ minikube kubectl -- get pods --namespace kube-system`,
 			version = cc.KubernetesConfig.KubernetesVersion
 		}
 
-		cluster := []string{"--cluster", ClusterFlagValue()}
-		args = append(cluster, args...)
+		cname := ClusterFlagValue()
+
+		if useSSH {
+			co := mustload.Running(cname)
+			n := co.CP.Node
+
+			kc := []string{"sudo"}
+			kc = append(kc, kubectlPath(*co.Config))
+			kc = append(kc, "--kubeconfig")
+			kc = append(kc, kubeconfigPath(*co.Config))
+			args = append(kc, args...)
+
+			klog.Infof("Running SSH %v", args)
+			err := machine.CreateSSHShell(co.API, *co.Config, *n, args, false)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "Error running kubectl: %v", err)
+				os.Exit(1)
+			}
+			return
+		}
+
+		if len(args) > 1 && args[0] != "--help" {
+			cluster := []string{"--cluster", cname}
+			args = append(cluster, args...)
+		}
 
 		c, err := KubectlCommand(version, args...)
 		if err != nil {
@@ -66,14 +101,24 @@ minikube kubectl -- get pods --namespace kube-system`,
 				waitStatus := exitError.Sys().(syscall.WaitStatus)
 				rc = waitStatus.ExitStatus()
 			} else {
-				fmt.Fprintf(os.Stderr, "Error running %s: %v\n", path, err)
+				fmt.Fprintf(os.Stderr, "Error running %s: %v\n", c.Path, err)
 				rc = 1
 			}
 			os.Exit(rc)
 		}
 	},
 }
 
+// kubectlPath returns the path to kubectl
+func kubectlPath(cfg config.ClusterConfig) string {
+	return path.Join(vmpath.GuestPersistentDir, "binaries", cfg.KubernetesConfig.KubernetesVersion, "kubectl")
+}
+
+// kubeconfigPath returns the path to kubeconfig
+func kubeconfigPath(cfg config.ClusterConfig) string {
+	return "/etc/kubernetes/admin.conf"
+}
+
 // KubectlCommand will return kubectl command with a version matching the cluster
 func KubectlCommand(version string, args ...string) (*exec.Cmd, error) {
 	if version == "" {
@@ -87,3 +132,7 @@ func KubectlCommand(version string, args ...string) (*exec.Cmd, error) {
 
 	return exec.Command(path, args...), nil
 }
+
+func init() {
+	kubectlCmd.Flags().BoolVar(&useSSH, "ssh", false, "Use SSH for running kubernetes client on the node")
+}

cmd/minikube/main.go

@@ -61,7 +61,10 @@ func main() {
 	bridgeLogMessages()
 	defer klog.Flush()
 
-	setFlags()
+	// Don't parse flags when running as kubectl
+	_, callingCmd := filepath.Split(os.Args[0])
+	parse := callingCmd != "kubectl"
+	setFlags(parse)
 
 	s := stacklog.MustStartFromEnv("STACKLOG_PATH")
 	defer s.Stop()
@@ -124,14 +127,16 @@ func (lb machineLogBridge) Write(b []byte) (n int, err error) {
 }
 
 // setFlags sets the flags
-func setFlags() {
+func setFlags(parse bool) {
 	// parse flags beyond subcommand - get aroung go flag 'limitations':
 	// "Flag parsing stops just before the first non-flag argument" (ref: https://pkg.go.dev/flag#hdr-Command_line_flag_syntax)
 	pflag.CommandLine.ParseErrorsWhitelist.UnknownFlags = true
 	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
 	// avoid 'pflag: help requested' error, as help will be defined later by cobra cmd.Execute()
 	pflag.BoolP("help", "h", false, "")
-	pflag.Parse()
+	if parse {
+		pflag.Parse()
+	}
 
 	// set default flag value for logtostderr and alsologtostderr but don't override user's preferences
 	if !pflag.CommandLine.Changed("logtostderr") {

site/content/en/docs/commands/kubectl.md

@@ -13,14 +13,30 @@ Run a kubectl binary matching the cluster version
 
 Run the Kubernetes client, download it if necessary. Remember -- after kubectl!
 
-Examples:
-minikube kubectl -- --help
-minikube kubectl -- get pods --namespace kube-system
+This will run the Kubernetes client (kubectl) with the same version as the cluster
+
+Normally it will download a binary matching the host operating system and architecture,
+but optionally you can also run it directly on the control plane over the ssh connection.
+This can be useful if you cannot run kubectl locally for some reason, like unsupported
+host. Please be aware that when using --ssh all paths will apply to the remote machine.
 
 ```shell
 minikube kubectl [flags]
 ```
 
+### Examples
+
+```
+minikube kubectl -- --help
+minikube kubectl -- get pods --namespace kube-system
+```
+
+### Options
+
+```
+      --ssh   Use SSH for running kubernetes client on the node
+```
+
 ### Options inherited from parent commands
 
 ```