github.com/mirantis/virtlet@v1.5.2-0.20191204181327-1659b8a48e9b/pkg/tools/install.go (about)

     1  /*
     2  Copyright 2018 Mirantis
     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  package tools
    18  
    19  import (
    20  	"errors"
    21  	"fmt"
    22  	"io"
    23  	"io/ioutil"
    24  	"os"
    25  	"path/filepath"
    26  
    27  	"github.com/renstrom/dedent"
    28  	"github.com/spf13/cobra"
    29  	"k8s.io/client-go/util/homedir"
    30  )
    31  
    32  const (
    33  	pluginName = "virt"
    34  )
    35  
    36  // installCommand is used to install virtletctl as a kubectl plugin.
    37  type installCommand struct {
    38  	rootCmd        *cobra.Command
    39  	executablePath string
    40  	homeDir        string
    41  }
    42  
    43  // NewInstallCmd returns a cobra.Command that installs virtletctl as a kubectl plugin.
    44  func NewInstallCmd(rootCmd *cobra.Command, executablePath, homeDir string) *cobra.Command {
    45  	install := &installCommand{
    46  		rootCmd:        rootCmd,
    47  		executablePath: executablePath,
    48  		homeDir:        homeDir,
    49  	}
    50  	return &cobra.Command{
    51  		Use:   "install",
    52  		Short: "Install virtletctl as a kubectl plugin",
    53  		Long: dedent.Dedent(`
    54                          This command install virtletctl as a kubectl plugin.
    55  
    56                          After running this command, it becomes possible to run virtletctl
    57                          via 'kubectl plugin virt'.`),
    58  		RunE: func(cmd *cobra.Command, args []string) error {
    59  			if len(args) != 0 {
    60  				return errors.New("This command does not accept arguments")
    61  			}
    62  			return install.Run()
    63  		},
    64  	}
    65  }
    66  
    67  // Run executes the command.
    68  func (inst *installCommand) Run() error {
    69  	if inst.executablePath == "" {
    70  		var err error
    71  		inst.executablePath, err = os.Executable()
    72  		if err != nil {
    73  			return fmt.Errorf("can't get executable path: %v", err)
    74  		}
    75  	}
    76  	if inst.homeDir == "" {
    77  		inst.homeDir = homedir.HomeDir()
    78  	}
    79  	oldUse := inst.rootCmd.Use
    80  	inst.rootCmd.Use = pluginName
    81  	defer func() {
    82  		inst.rootCmd.Use = oldUse
    83  	}()
    84  
    85  	pluginDir := filepath.Join(inst.homeDir, ".kube", "plugins", inst.rootCmd.Name())
    86  	if err := os.MkdirAll(pluginDir, 0755); err != nil {
    87  		return fmt.Errorf("MkdirAll(): %v", err)
    88  	}
    89  
    90  	srcPath := filepath.Clean(inst.executablePath)
    91  	src, err := os.Open(srcPath)
    92  	if err != nil {
    93  		return fmt.Errorf("read opening virtletctl executable file %q: %v", srcPath, err)
    94  	}
    95  	defer src.Close()
    96  
    97  	dstPath := filepath.Join(pluginDir, inst.rootCmd.Name())
    98  	dst, err := os.OpenFile(dstPath, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0755)
    99  	if err != nil {
   100  		return fmt.Errorf("error creating kubectl plugin binary file %q: %v", dstPath, err)
   101  	}
   102  	defer dst.Close()
   103  	if _, err := io.Copy(dst, src); err != nil {
   104  		return fmt.Errorf("error copying virtletctl: %q -> %q: %v", srcPath, dstPath, err)
   105  	}
   106  
   107  	pluginYaml := pluginYamlFromCobraCommand(inst.rootCmd)
   108  	pluginYamlPath := filepath.Join(pluginDir, "plugin.yaml")
   109  	if err := ioutil.WriteFile(pluginYamlPath, pluginYaml, 0644); err != nil {
   110  		return fmt.Errorf("error writing plugin.yaml: %v", err)
   111  	}
   112  
   113  	return nil
   114  }