github.com/supr/packer@v0.3.10-0.20131015195147-7b09e24ac3c1/builder/amazon/chroot/communicator.go (about)

     1  package chroot
     2  
     3  import (
     4  	"fmt"
     5  	"github.com/mitchellh/packer/packer"
     6  	"io"
     7  	"io/ioutil"
     8  	"log"
     9  	"os"
    10  	"os/exec"
    11  	"path/filepath"
    12  	"syscall"
    13  )
    14  
    15  // Communicator is a special communicator that works by executing
    16  // commands locally but within a chroot.
    17  type Communicator struct {
    18  	Chroot     string
    19  	CmdWrapper CommandWrapper
    20  }
    21  
    22  func (c *Communicator) Start(cmd *packer.RemoteCmd) error {
    23  	command, err := c.CmdWrapper(
    24  		fmt.Sprintf("chroot %s %s", c.Chroot, cmd.Command))
    25  	if err != nil {
    26  		return err
    27  	}
    28  
    29  	localCmd := ShellCommand(command)
    30  	localCmd.Stdin = cmd.Stdin
    31  	localCmd.Stdout = cmd.Stdout
    32  	localCmd.Stderr = cmd.Stderr
    33  	log.Printf("Executing: %s %#v", localCmd.Path, localCmd.Args)
    34  	if err := localCmd.Start(); err != nil {
    35  		return err
    36  	}
    37  
    38  	go func() {
    39  		exitStatus := 0
    40  		if err := localCmd.Wait(); err != nil {
    41  			if exitErr, ok := err.(*exec.ExitError); ok {
    42  				exitStatus = 1
    43  
    44  				// There is no process-independent way to get the REAL
    45  				// exit status so we just try to go deeper.
    46  				if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
    47  					exitStatus = status.ExitStatus()
    48  				}
    49  			}
    50  		}
    51  
    52  		log.Printf(
    53  			"Chroot execution exited with '%d': '%s'",
    54  			exitStatus, cmd.Command)
    55  		cmd.SetExited(exitStatus)
    56  	}()
    57  
    58  	return nil
    59  }
    60  
    61  func (c *Communicator) Upload(dst string, r io.Reader) error {
    62  	dst = filepath.Join(c.Chroot, dst)
    63  	log.Printf("Uploading to chroot dir: %s", dst)
    64  	tf, err := ioutil.TempFile("", "packer-amazon-chroot")
    65  	if err != nil {
    66  		return fmt.Errorf("Error preparing shell script: %s", err)
    67  	}
    68  	defer os.Remove(tf.Name())
    69  	io.Copy(tf, r)
    70  
    71  	cpCmd, err := c.CmdWrapper(fmt.Sprintf("cp %s %s", tf.Name(), dst))
    72  	if err != nil {
    73  		return err
    74  	}
    75  
    76  	return ShellCommand(cpCmd).Run()
    77  }
    78  
    79  func (c *Communicator) UploadDir(dst string, src string, exclude []string) error {
    80  	// TODO: remove any file copied if it appears in `exclude`
    81  	chrootDest := filepath.Join(c.Chroot, dst)
    82  	log.Printf("Uploading directory '%s' to '%s'", src, chrootDest)
    83  	cpCmd, err := c.CmdWrapper(fmt.Sprintf("cp -R %s* %s", src, chrootDest))
    84  	if err != nil {
    85  		return err
    86  	}
    87  
    88  	return ShellCommand(cpCmd).Run()
    89  }
    90  
    91  func (c *Communicator) Download(src string, w io.Writer) error {
    92  	src = filepath.Join(c.Chroot, src)
    93  	log.Printf("Downloading from chroot dir: %s", src)
    94  	f, err := os.Open(src)
    95  	if err != nil {
    96  		return err
    97  	}
    98  	defer f.Close()
    99  
   100  	if _, err := io.Copy(w, f); err != nil {
   101  		return err
   102  	}
   103  
   104  	return nil
   105  }