builder/amazon/chroot: mount extra paths

builder/amazon/chroot/builder.go

@@ -24,13 +24,13 @@ type Config struct {
 	common.PackerConfig    `mapstructure:",squash"`
 	awscommon.AccessConfig `mapstructure:",squash"`
 
-	AttachedDevicePath string   `mapstructure:"attached_device_path"`
-	ChrootMounts       []string `mapstructure:"chroot_mounts"`
-	DevicePath         string   `mapstructure:"device_path"`
-	MountCommand       string   `mapstructure:"mount_command"`
-	MountPath          string   `mapstructure:"mount_path"`
-	SourceAmi          string   `mapstructure:"source_ami"`
-	UnmountCommand     string   `mapstructure:"unmount_command"`
+	AttachedDevicePath string     `mapstructure:"attached_device_path"`
+	ChrootMounts       [][]string `mapstructure:"chroot_mounts"`
+	DevicePath         string     `mapstructure:"device_path"`
+	MountCommand       string     `mapstructure:"mount_command"`
+	MountPath          string     `mapstructure:"mount_path"`
+	SourceAmi          string     `mapstructure:"source_ami"`
+	UnmountCommand     string     `mapstructure:"unmount_command"`
 }
 
 type Builder struct {
@@ -46,16 +46,16 @@ func (b *Builder) Prepare(raws ...interface{}) error {
 
 	// Defaults
 	if b.config.ChrootMounts == nil {
-		b.config.ChrootMounts = make([]string, 0)
+		b.config.ChrootMounts = make([][]string, 0)
 	}
 
 	if len(b.config.ChrootMounts) == 0 {
-		b.config.ChrootMounts = []string{
-			"{{.MountCommand}} -t proc proc {{.MountPath}}/proc",
-			"{{.MountCommand}} -t sysfs sysfs {{.MountPath}}/sys",
-			"{{.MountCommand}} -t bind /dev {{.MountPath}}/dev",
-			"{{.MountCommand}} -t devpts devpts {{.MountPath}}/dev/pts",
-			"{{.MountCommand}} -t binfmt_misc binfmt_misc {{.MountPath}}/proc/sys/fs/binfmt_misc",
+		b.config.ChrootMounts = [][]string{
+			[]string{"proc", "proc", "/proc"},
+			[]string{"sysfs", "sysfs", "/sys"},
+			[]string{"bind", "/dev", "/dev"},
+			[]string{"devpts", "devpts", "/dev/pts"},
+			[]string{"binfmt_misc", "binfmt_misc", "/proc/sys/fs/binfmt_misc"},
 		}
 	}
 
@@ -126,6 +126,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		&StepCreateVolume{},
 		&StepAttachVolume{},
 		&StepMountDevice{},
+		&StepMountExtra{},
 	}
 
 	// Run!

builder/amazon/chroot/step_mount_device.go

@@ -32,7 +32,7 @@ func (s *StepMountDevice) Run(state map[string]interface{}) multistep.StepAction
 	mountPathRaw := new(bytes.Buffer)
 	t := template.Must(template.New("mountPath").Parse(config.MountPath))
 	t.Execute(mountPathRaw, &mountPathData{
-		Device: filepath.Basename(device),
+		Device: filepath.Base(device),
 	})
 
 	mountPath := mountPathRaw.String()
@@ -60,6 +60,7 @@ func (s *StepMountDevice) Run(state map[string]interface{}) multistep.StepAction
 
 	// Set the mount path so we remember to unmount it later
 	s.mountPath = mountPath
+	state["mount_path"] = s.mountPath
 
 	return multistep.ActionContinue
 }

builder/amazon/chroot/step_mount_extra.go

@@ -0,0 +1,79 @@
+package chroot
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+	"os"
+	"os/exec"
+)
+
+// StepMountExtra mounts the attached device.
+//
+// Produces:
+//   mount_path string - The location where the volume was mounted.
+type StepMountExtra struct {
+	mounts []string
+}
+
+func (s *StepMountExtra) Run(state map[string]interface{}) multistep.StepAction {
+	config := state["config"].(*Config)
+	mountPath := state["mount_path"].(string)
+	ui := state["ui"].(packer.Ui)
+
+	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["error"] = err
+			ui.Error(err.Error())
+			return multistep.ActionHalt
+		}
+
+		ui.Message(fmt.Sprintf("Mounting: %s", mountInfo[2]))
+		stderr := new(bytes.Buffer)
+		mountCommand := fmt.Sprintf(
+			"%s -t %s %s %s",
+			config.MountCommand,
+			mountInfo[0],
+			mountInfo[1],
+			innerPath)
+		cmd := exec.Command("/bin/sh", "-c", mountCommand)
+		cmd.Stderr = stderr
+		if err := cmd.Run(); err != nil {
+			err := fmt.Errorf(
+				"Error mounting: %s\nStderr: %s", err, stderr.String())
+			state["error"] = err
+			ui.Error(err.Error())
+			return multistep.ActionHalt
+		}
+
+		s.mounts = append(s.mounts, innerPath)
+	}
+
+	return multistep.ActionContinue
+}
+
+func (s *StepMountExtra) Cleanup(state map[string]interface{}) {
+	if s.mounts == nil {
+		return
+	}
+
+	config := state["config"].(*Config)
+	ui := state["ui"].(packer.Ui)
+
+	for _, path := range s.mounts {
+		unmountCommand := fmt.Sprintf("%s %s", config.UnmountCommand, path)
+		cmd := exec.Command("bin/sh", "-c", unmountCommand)
+		if err := cmd.Run(); err != nil {
+			ui.Error(fmt.Sprintf(
+				"Error unmounting root device: %s", err))
+			return
+		}
+	}
+}