Add custom user defined/ controlled manual mount command option

.web-docs/components/builder/chroot/README.md

@@ -122,6 +122,10 @@ necessary for this build to succeed and can be found further down the page.
   template where the .Device variable is replaced with the name of the
   device where the volume is attached.
 
+- `manual_mount_command` (string) - Manual Mount Command that is executed to manually mount the
+  root device, partition, and unmount. All other mount steps are skipped.
+  The device andmount path are provided by `{{.Device}}` and `{{.MountPath}}`.
+
 - `post_mount_commands` ([]string) - As pre_mount_commands, but the commands are executed after mounting the
   root device and before the extra mount and copy steps. The device and
   mount path are provided by `{{.Device}}` and `{{.MountPath}}`.

builder/chroot/builder.go

@@ -98,6 +98,10 @@ type Config struct {
 	// template where the .Device variable is replaced with the name of the
 	// device where the volume is attached.
 	MountPath string `mapstructure:"mount_path" required:"false"`
+	// Manual Mount Command that is executed to manually mount the
+	// root device, partition, and unmount. All other mount steps are skipped.
+	// The device andmount path are provided by `{{.Device}}` and `{{.MountPath}}`.
+	ManualMountCommand string `mapstructure:"manual_mount_command" required:"false"`
 	// As pre_mount_commands, but the commands are executed after mounting the
 	// root device and before the extra mount and copy steps. The device and
 	// mount path are provided by `{{.Device}}` and `{{.MountPath}}`.
@@ -245,6 +249,7 @@ func (b *Builder) Prepare(raws ...interface{}) ([]string, []string, error) {
 				"root_volume_tag",
 				"command_wrapper",
 				"post_mount_commands",
+				"manual_mount_command",
 				"pre_mount_commands",
 				"mount_path",
 			},
@@ -321,9 +326,9 @@ func (b *Builder) Prepare(raws ...interface{}) ([]string, []string, error) {
 			errs = packersdk.MultiErrorAppend(
 				errs, errors.New("root_volume_size is required with from_scratch."))
 		}
-		if len(b.config.PreMountCommands) == 0 {
+		if b.config.ManualMountCommand == "" && len(b.config.PreMountCommands) == 0 {
 			errs = packersdk.MultiErrorAppend(
-				errs, errors.New("pre_mount_commands is required with from_scratch."))
+				errs, errors.New("pre_mount_commands or manual_mount_command is required with from_scratch."))
 		}
 		if b.config.AMIVirtType == "" {
 			errs = packersdk.MultiErrorAppend(
@@ -480,17 +485,32 @@ func (b *Builder) Run(ctx context.Context, ui packersdk.Ui, hook packersdk.Hook)
 			PollingConfig: b.config.PollingConfig,
 		},
 		&StepEarlyUnflock{},
-		&chroot.StepPreMountCommands{
-			Commands: b.config.PreMountCommands,
-		},
-		&StepMountDevice{
-			MountOptions:   b.config.MountOptions,
-			MountPartition: b.config.MountPartition,
-			GeneratedData:  generatedData,
-		},
-		&chroot.StepPostMountCommands{
-			Commands: b.config.PostMountCommands,
-		},
+	)
+
+	if b.config.ManualMountCommand != "" {
+		steps = append(steps,
+			&StepManualMountCommand{
+				Command:       b.config.ManualMountCommand,
+				GeneratedData: generatedData,
+			},
+		)
+	} else {
+		steps = append(steps,
+			&chroot.StepPreMountCommands{
+				Commands: b.config.PreMountCommands,
+			},
+			&StepMountDevice{
+				MountOptions:   b.config.MountOptions,
+				MountPartition: b.config.MountPartition,
+				GeneratedData:  generatedData,
+			},
+			&chroot.StepPostMountCommands{
+				Commands: b.config.PostMountCommands,
+			},
+		)
+	}
+
+	steps = append(steps,
 		&chroot.StepMountExtra{
 			ChrootMounts: b.config.ChrootMounts,
 		},

builder/chroot/step_manual_mount_command.go

@@ -0,0 +1,117 @@
+package chroot
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"log"
+	"path/filepath"
+
+	"github.com/hashicorp/packer-plugin-sdk/common"
+	"github.com/hashicorp/packer-plugin-sdk/multistep"
+	packersdk "github.com/hashicorp/packer-plugin-sdk/packer"
+	"github.com/hashicorp/packer-plugin-sdk/packerbuilderdata"
+	"github.com/hashicorp/packer-plugin-sdk/template/interpolate"
+)
+
+type manualMountCommandData struct {
+	Device string
+}
+
+// StepManualMountCommand sets up the a new block device when building from scratch
+type StepManualMountCommand struct {
+	Command   string
+	mountPath string
+
+	GeneratedData *packerbuilderdata.GeneratedData
+}
+
+func (s *StepManualMountCommand) Run(ctx context.Context, state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*Config)
+	device := state.Get("device").(string)
+	ui := state.Get("ui").(packersdk.Ui)
+
+	ui.Say("Running manual mount commands...")
+
+	if config.NVMEDevicePath != "" {
+		// customizable device path for mounting NVME block devices on c5 and m5 HVM
+		device = config.NVMEDevicePath
+	}
+	ui.Say(fmt.Sprintf("Command is: %s", s.Command))
+	if len(s.Command) == 0 {
+		return multistep.ActionContinue
+	}
+
+	ictx := config.GetContext()
+	ictx.Data = &manualMountCommandData{Device: filepath.Base(device)}
+	mountPath, err := interpolate.Render(config.MountPath, &ictx)
+
+	if err != nil {
+		err := fmt.Errorf("Error preparing mount directory: %s", err)
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	mountPath, err = filepath.Abs(mountPath)
+	if err != nil {
+		err := fmt.Errorf("Error preparing mount directory: %s", err)
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	ui.Say(fmt.Sprintf("Mount Path After ABS is: %s", mountPath))
+
+	log.Printf("Mount path: %s", mountPath)
+	stderr := new(bytes.Buffer)
+
+	wrappedCommand := state.Get("wrappedCommand").(common.CommandWrapper)
+
+	ui.Say("Running manual mount commands...")
+	mountCommand, err := wrappedCommand(s.Command)
+	if err != nil {
+		err := fmt.Errorf("Error creating mount command: %s", err)
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	cmd := common.ShellCommand(mountCommand)
+	cmd.Stderr = stderr
+	if err := cmd.Run(); err != nil {
+		err := fmt.Errorf(
+			"Error mounting root volume: %s\nStderr: %s", err, stderr.String())
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	// Set the mount path so we remember to unmount it later
+	s.mountPath = mountPath
+	state.Put("mount_path", s.mountPath)
+	s.GeneratedData.Put("MountPath", s.mountPath)
+	state.Put("mount_device_cleanup", s)
+
+	return multistep.ActionContinue
+}
+
+func (s *StepManualMountCommand) Cleanup(state multistep.StateBag) {
+	ui := state.Get("ui").(packersdk.Ui)
+	if err := s.CleanupFunc(state); err != nil {
+		ui.Error(err.Error())
+	}
+}
+
+func (s *StepManualMountCommand) CleanupFunc(state multistep.StateBag) error {
+	if s.mountPath == "" {
+		return nil
+	}
+
+	ui := state.Get("ui").(packersdk.Ui)
+
+	ui.Say("Skipping UnMount Root Mount, it must be manually unmounted...")
+
+	s.mountPath = ""
+	return nil
+}

docs-partials/builder/chroot/Config-not-required.mdx

@@ -60,6 +60,10 @@
   template where the .Device variable is replaced with the name of the
   device where the volume is attached.
 
+- `manual_mount_command` (string) - Manual Mount Command that is executed to manually mount the
+  root device, partition, and unmount. All other mount steps are skipped.
+  The device andmount path are provided by `{{.Device}}` and `{{.MountPath}}`.
+
 - `post_mount_commands` ([]string) - As pre_mount_commands, but the commands are executed after mounting the
   root device and before the extra mount and copy steps. The device and
   mount path are provided by `{{.Device}}` and `{{.MountPath}}`.