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 }