feature: add root block device config to bsusurrogate config struct

builder/osc/bsusurrogate/builder.go

@@ -20,7 +20,10 @@ type Config struct {
 	osccommon.RunConfig    `mapstructure:",squash"`
 	osccommon.BlockDevices `mapstructure:",squash"`
 	osccommon.OMIConfig    `mapstructure:",squash"`
-	ctx                    interpolate.Context
+
+	RootDevice RootBlockDevice `mapstructure:"ami_root_device"`
+
+	ctx interpolate.Context
 }
 
 type Builder struct {

builder/osc/bsusurrogate/root_block_device.go

@@ -0,0 +1,46 @@
+package bsusurrogate
+
+import (
+	"errors"
+
+	"github.com/hashicorp/packer/template/interpolate"
+)
+
+type RootBlockDevice struct {
+	SourceDeviceName   string `mapstructure:"source_device_name"`
+	DeviceName         string `mapstructure:"device_name"`
+	DeleteOnVmDeletion bool   `mapstructure:"delete_on_vm_deletion"`
+	IOPS               int64  `mapstructure:"iops"`
+	VolumeType         string `mapstructure:"volume_type"`
+	VolumeSize         int64  `mapstructure:"volume_size"`
+}
+
+func (c *RootBlockDevice) Prepare(ctx *interpolate.Context) []error {
+	var errs []error
+
+	if c.SourceDeviceName == "" {
+		errs = append(errs, errors.New("source_device_name for the root_device must be specified"))
+	}
+
+	if c.DeviceName == "" {
+		errs = append(errs, errors.New("device_name for the root_device must be specified"))
+	}
+
+	if c.VolumeType == "gp2" && c.IOPS != 0 {
+		errs = append(errs, errors.New("iops may not be specified for a gp2 volume"))
+	}
+
+	if c.IOPS < 0 {
+		errs = append(errs, errors.New("iops must be greater than 0"))
+	}
+
+	if c.VolumeSize < 0 {
+		errs = append(errs, errors.New("volume_size must be greater than 0"))
+	}
+
+	if len(errs) > 0 {
+		return errs
+	}
+
+	return nil
+}