Enable setting the volume type when building with the Amazon Chroot builder

builder/amazon/chroot/builder.go

@@ -42,6 +42,7 @@ type Config struct {
 	PreMountCommands  []string                   `mapstructure:"pre_mount_commands"`
 	RootDeviceName    string                     `mapstructure:"root_device_name"`
 	RootVolumeSize    int64                      `mapstructure:"root_volume_size"`
+	RootVolumeType    string                     `mapstructure:"root_volume_type"`
 	SourceAmi         string                     `mapstructure:"source_ami"`
 	SourceAmiFilter   awscommon.AmiFilterOptions `mapstructure:"source_ami_filter"`
 	RootVolumeTags    awscommon.TagMap           `mapstructure:"root_volume_tags"`
@@ -233,6 +234,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		&StepFlock{},
 		&StepPrepareDevice{},
 		&StepCreateVolume{
+			RootVolumeType: b.config.RootVolumeType,
 			RootVolumeSize: b.config.RootVolumeSize,
 			RootVolumeTags: b.config.RootVolumeTags,
 			Ctx:            b.config.ctx,

builder/amazon/chroot/step_create_volume.go

@@ -21,6 +21,7 @@ import (
 type StepCreateVolume struct {
 	volumeId       string
 	RootVolumeSize int64
+	RootVolumeType string
 	RootVolumeTags awscommon.TagMap
 	Ctx            interpolate.Context
 }
@@ -70,26 +71,13 @@ func (s *StepCreateVolume) Run(ctx context.Context, state multistep.StateBag) mu
 			}
 		}
 
-		if rootDevice == nil {
-			err := fmt.Errorf("Couldn't find root device!")
+		ui.Say("Creating the root volume...")
+		createVolume, err = s.buildCreateVolumeInput(*instance.Placement.AvailabilityZone, rootDevice)
+		if err != nil {
 			state.Put("error", err)
 			ui.Error(err.Error())
 			return multistep.ActionHalt
 		}
-
-		ui.Say("Creating the root volume...")
-		vs := *rootDevice.Ebs.VolumeSize
-		if s.RootVolumeSize > *rootDevice.Ebs.VolumeSize {
-			vs = s.RootVolumeSize
-		}
-
-		createVolume = &ec2.CreateVolumeInput{
-			AvailabilityZone: instance.Placement.AvailabilityZone,
-			Size:             aws.Int64(vs),
-			SnapshotId:       rootDevice.Ebs.SnapshotId,
-			VolumeType:       rootDevice.Ebs.VolumeType,
-			Iops:             rootDevice.Ebs.Iops,
-		}
 	}
 
 	if len(tagSpecs) > 0 {
@@ -137,3 +125,33 @@ func (s *StepCreateVolume) Cleanup(state multistep.StateBag) {
 		ui.Error(fmt.Sprintf("Error deleting EBS volume: %s", err))
 	}
 }
+
+func (s *StepCreateVolume) buildCreateVolumeInput(az string, rootDevice *ec2.BlockDeviceMapping) (*ec2.CreateVolumeInput, error) {
+	if rootDevice == nil {
+		return nil, fmt.Errorf("Couldn't find root device!")
+	}
+	createVolumeInput := &ec2.CreateVolumeInput{
+		AvailabilityZone: aws.String(az),
+		Size:             rootDevice.Ebs.VolumeSize,
+		SnapshotId:       rootDevice.Ebs.SnapshotId,
+		VolumeType:       rootDevice.Ebs.VolumeType,
+		Iops:             rootDevice.Ebs.Iops,
+	}
+	if s.RootVolumeSize > *rootDevice.Ebs.VolumeSize {
+		createVolumeInput.Size = aws.Int64(s.RootVolumeSize)
+	}
+
+	if s.RootVolumeType == "" || s.RootVolumeType == *rootDevice.Ebs.VolumeType {
+		return createVolumeInput, nil
+	}
+
+	if s.RootVolumeType == "io1" {
+		return nil, fmt.Errorf("Root volume type cannot be io1, because existing root volume type was %s", *rootDevice.Ebs.VolumeType)
+	}
+
+	createVolumeInput.VolumeType = aws.String(s.RootVolumeType)
+	// non io1 cannot set iops
+	createVolumeInput.Iops = nil
+
+	return createVolumeInput, nil
+}

builder/amazon/chroot/step_create_volume_test.go

@@ -0,0 +1,73 @@
+package chroot
+
+import (
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/service/ec2"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func buildTestRootDevice() *ec2.BlockDeviceMapping {
+	return &ec2.BlockDeviceMapping{
+		Ebs: &ec2.EbsBlockDevice{
+			VolumeSize: aws.Int64(10),
+			SnapshotId: aws.String("snap-1234"),
+			VolumeType: aws.String("gp2"),
+		},
+	}
+}
+
+func TestCreateVolume_Default(t *testing.T) {
+	stepCreateVolume := new(StepCreateVolume)
+	_, err := stepCreateVolume.buildCreateVolumeInput("test-az", buildTestRootDevice())
+	assert.NoError(t, err)
+}
+
+func TestCreateVolume_Shrink(t *testing.T) {
+	stepCreateVolume := StepCreateVolume{RootVolumeSize: 1}
+	testRootDevice := buildTestRootDevice()
+	ret, err := stepCreateVolume.buildCreateVolumeInput("test-az", testRootDevice)
+	assert.NoError(t, err)
+	// Ensure that the new value is equal to the size of the old root device
+	assert.Equal(t, *ret.Size, *testRootDevice.Ebs.VolumeSize)
+}
+
+func TestCreateVolume_Expand(t *testing.T) {
+	stepCreateVolume := StepCreateVolume{RootVolumeSize: 25}
+	testRootDevice := buildTestRootDevice()
+	ret, err := stepCreateVolume.buildCreateVolumeInput("test-az", testRootDevice)
+	assert.NoError(t, err)
+	// Ensure that the new value is equal to the size of the value passed in
+	assert.Equal(t, *ret.Size, stepCreateVolume.RootVolumeSize)
+}
+
+func TestCreateVolume_io1_to_io1(t *testing.T) {
+	stepCreateVolume := StepCreateVolume{RootVolumeType: "io1"}
+	testRootDevice := buildTestRootDevice()
+	testRootDevice.Ebs.VolumeType = aws.String("io1")
+	testRootDevice.Ebs.Iops = aws.Int64(1000)
+	ret, err := stepCreateVolume.buildCreateVolumeInput("test-az", testRootDevice)
+	assert.NoError(t, err)
+	assert.Equal(t, *ret.VolumeType, stepCreateVolume.RootVolumeType)
+	assert.Equal(t, *ret.Iops, *testRootDevice.Ebs.Iops)
+}
+
+func TestCreateVolume_io1_to_gp2(t *testing.T) {
+	stepCreateVolume := StepCreateVolume{RootVolumeType: "gp2"}
+	testRootDevice := buildTestRootDevice()
+	testRootDevice.Ebs.VolumeType = aws.String("io1")
+	testRootDevice.Ebs.Iops = aws.Int64(1000)
+
+	ret, err := stepCreateVolume.buildCreateVolumeInput("test-az", testRootDevice)
+	assert.NoError(t, err)
+	assert.Equal(t, *ret.VolumeType, stepCreateVolume.RootVolumeType)
+	assert.Nil(t, ret.Iops)
+}
+
+func TestCreateVolume_gp2_to_io1(t *testing.T) {
+	stepCreateVolume := StepCreateVolume{RootVolumeType: "io1"}
+	testRootDevice := buildTestRootDevice()
+
+	_, err := stepCreateVolume.buildCreateVolumeInput("test-az", testRootDevice)
+	assert.Error(t, err)
+}