packer-cn/builder/amazon/chroot/step_mount_extra.go

136 lines
3.3 KiB
Go

package chroot
import (
"bytes"
"fmt"
"github.com/mitchellh/multistep"
"github.com/mitchellh/packer/packer"
"os"
"os/exec"
"syscall"
)
// StepMountExtra mounts the attached device.
//
// Produces:
// mount_extra_cleanup CleanupFunc - To perform early cleanup
type StepMountExtra struct {
mounts []string
}
func (s *StepMountExtra) Run(state multistep.StateBag) multistep.StepAction {
config := state.Get("config").(*Config)
mountPath := state.Get("mount_path").(string)
ui := state.Get("ui").(packer.Ui)
wrappedCommand := state.Get("wrappedCommand").(CommandWrapper)
s.mounts = make([]string, 0, len(config.ChrootMounts))
ui.Say("Mounting additional paths within the chroot...")
for _, mountInfo := range config.ChrootMounts {
innerPath := mountPath + mountInfo[2]
if err := os.MkdirAll(innerPath, 0755); err != nil {
err := fmt.Errorf("Error creating mount directory: %s", err)
state.Put("error", err)
ui.Error(err.Error())
return multistep.ActionHalt
}
flags := "-t " + mountInfo[0]
if mountInfo[0] == "bind" {
flags = "--bind"
}
ui.Message(fmt.Sprintf("Mounting: %s", mountInfo[2]))
stderr := new(bytes.Buffer)
mountCommand, err := wrappedCommand(fmt.Sprintf(
"mount %s %s %s",
flags,
mountInfo[1],
innerPath))
if err != nil {
err := fmt.Errorf("Error creating mount command: %s", err)
state.Put("error", err)
ui.Error(err.Error())
return multistep.ActionHalt
}
cmd := ShellCommand(mountCommand)
cmd.Stderr = stderr
if err := cmd.Run(); err != nil {
err := fmt.Errorf(
"Error mounting: %s\nStderr: %s", err, stderr.String())
state.Put("error", err)
ui.Error(err.Error())
return multistep.ActionHalt
}
s.mounts = append(s.mounts, innerPath)
}
state.Put("mount_extra_cleanup", s)
return multistep.ActionContinue
}
func (s *StepMountExtra) Cleanup(state multistep.StateBag) {
ui := state.Get("ui").(packer.Ui)
if err := s.CleanupFunc(state); err != nil {
ui.Error(err.Error())
return
}
}
func (s *StepMountExtra) CleanupFunc(state multistep.StateBag) error {
if s.mounts == nil {
return nil
}
wrappedCommand := state.Get("wrappedCommand").(CommandWrapper)
for len(s.mounts) > 0 {
var path string
lastIndex := len(s.mounts) - 1
path, s.mounts = s.mounts[lastIndex], s.mounts[:lastIndex]
grepCommand, err := wrappedCommand(fmt.Sprintf("grep %s /proc/mounts", path))
if err != nil {
return fmt.Errorf("Error creating grep command: %s", err)
}
// Before attempting to unmount,
// check to see if path is already unmounted
stderr := new(bytes.Buffer)
cmd := ShellCommand(grepCommand)
cmd.Stderr = stderr
if err := cmd.Run(); err != nil {
if exitError, ok := err.(*exec.ExitError); ok {
if status, ok := exitError.Sys().(syscall.WaitStatus); ok {
exitStatus := status.ExitStatus()
if exitStatus == 1 {
// path has already been unmounted
// just skip this path
continue
}
}
}
}
unmountCommand, err := wrappedCommand(fmt.Sprintf("umount %s", path))
if err != nil {
return fmt.Errorf("Error creating unmount command: %s", err)
}
stderr = new(bytes.Buffer)
cmd = ShellCommand(unmountCommand)
cmd.Stderr = stderr
if err := cmd.Run(); err != nil {
return fmt.Errorf(
"Error unmounting device: %s\nStderr: %s", err, stderr.String())
}
}
s.mounts = nil
return nil
}