Initial implementation of kubectl command

Some duplication, always using default k8s

cmd/minikube/cmd/kubectl.go

@@ -0,0 +1,104 @@
+/*
+Copyright 2019 The Kubernetes Authors All rights reserved.
+
+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 cmd
+
+import (
+	"crypto"
+	"fmt"
+	"os"
+	"os/exec"
+	"path"
+	"runtime"
+
+	"github.com/golang/glog"
+	download "github.com/jimmidyson/go-download"
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+	"k8s.io/minikube/pkg/minikube/constants"
+	"k8s.io/minikube/pkg/minikube/machine"
+)
+
+// kubectlCmd represents the kubectl command
+var kubectlCmd = &cobra.Command{
+	Use:   "kubectl",
+	Short: "Run kubectl",
+	Long:  `Run the kubernetes client, download it if necessary.`,
+	Run: func(cmd *cobra.Command, args []string) {
+		api, err := machine.NewAPIClient()
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error getting client: %v\n", err)
+			os.Exit(1)
+		}
+		defer api.Close()
+
+		binary := "kubectl"
+		if runtime.GOOS == "windows" {
+			binary = "kubectl.exe"
+		}
+		version := constants.DefaultKubernetesVersion
+		path, err := maybeDownloadAndCache(binary, version)
+
+		glog.Infof("Running %s %v", binary, args)
+		c := exec.Command(path, args...)
+		c.Stdout = os.Stdout
+		c.Stderr = os.Stderr
+		if err := c.Run(); err != nil {
+			fmt.Fprintf(os.Stderr, "Error running %s: %v\n", path, err)
+			os.Exit(1)
+		}
+	},
+}
+
+func maybeDownloadAndCache(binary, version string) (string, error) {
+	targetDir := constants.MakeMiniPath("cache", version)
+	targetFilepath := path.Join(targetDir, binary)
+
+	_, err := os.Stat(targetFilepath)
+	// If it exists, do no verification and continue
+	if err == nil {
+		return targetFilepath, nil
+	}
+	if !os.IsNotExist(err) {
+		return "", errors.Wrapf(err, "stat %s version %s at %s", binary, version, targetDir)
+	}
+
+	if err = os.MkdirAll(targetDir, 0777); err != nil {
+		return "", errors.Wrapf(err, "mkdir %s", targetDir)
+	}
+
+	url := constants.GetKubernetesClientReleaseURL(binary, version)
+	options := download.FileOptions{
+		Mkdirs: download.MkdirAll,
+	}
+
+	options.Checksum = constants.GetKubernetesClientReleaseURLSha1(binary, version)
+	options.ChecksumHash = crypto.SHA1
+
+	glog.Infof("Downloading %s %s", binary, version)
+	if err := download.ToFile(url, targetFilepath, options); err != nil {
+		return "", errors.Wrapf(err, "Error downloading %s %s", binary, version)
+	}
+	glog.Infof("Finished Downloading %s %s", binary, version)
+	if err = os.Chmod(targetFilepath, 0755); err != nil {
+		return "", errors.Wrapf(err, "chmod +x %s", targetFilepath)
+	}
+	return targetFilepath, nil
+}
+
+func init() {
+	RootCmd.AddCommand(kubectlCmd)
+}

pkg/minikube/constants/constants.go

@@ -168,10 +168,18 @@ func GetKubernetesReleaseURL(binaryName, version string) string {
 	return fmt.Sprintf("https://storage.googleapis.com/kubernetes-release/release/%s/bin/linux/%s/%s", version, runtime.GOARCH, binaryName)
 }
 
+func GetKubernetesClientReleaseURL(binaryName, version string) string {
+	return fmt.Sprintf("https://storage.googleapis.com/kubernetes-release/release/%s/bin/%s/%s/%s", version, runtime.GOOS, runtime.GOARCH, binaryName)
+}
+
 func GetKubernetesReleaseURLSha1(binaryName, version string) string {
 	return fmt.Sprintf("%s.sha1", GetKubernetesReleaseURL(binaryName, version))
 }
 
+func GetKubernetesClientReleaseURLSha1(binaryName, version string) string {
+	return fmt.Sprintf("%s.sha1", GetKubernetesClientReleaseURL(binaryName, version))
+}
+
 const IsMinikubeChildProcess = "IS_MINIKUBE_CHILD_PROCESS"
 const DriverNone = "none"
 const FileScheme = "file"