add omit_from_artifact option for ebssurragote launch_block_devices

builder/amazon/common/block_device.go

@@ -21,6 +21,8 @@ type BlockDevice struct {
 	VolumeType          string `mapstructure:"volume_type"`
 	VolumeSize          int64  `mapstructure:"volume_size"`
 	KmsKeyId            string `mapstructure:"kms_key_id"`
+	// ebssurrogate only
+	OmitFromArtifact bool `mapstructure:"omit_from_artifact"`
 }
 
 type BlockDevices struct {
@@ -96,6 +98,7 @@ func (b *BlockDevice) Prepare(ctx *interpolate.Context) error {
 		return fmt.Errorf("The device %v, must also have `encrypted: "+
 			"true` when setting a kms_key_id.", b.DeviceName)
 	}
+
 	return nil
 }
 
@@ -120,3 +123,13 @@ func (b *AMIBlockDevices) BuildAMIDevices() []*ec2.BlockDeviceMapping {
 func (b *LaunchBlockDevices) BuildLaunchDevices() []*ec2.BlockDeviceMapping {
 	return buildBlockDevices(b.LaunchMappings)
 }
+
+func (b *LaunchBlockDevices) GetOmissions() map[string]bool {
+	omitMap := make(map[string]bool)
+
+	for _, blockDevice := range b.LaunchMappings {
+		omitMap[blockDevice.DeviceName] = blockDevice.OmitFromArtifact
+	}
+
+	return omitMap
+}

builder/amazon/ebssurrogate/builder.go

@@ -79,6 +79,9 @@ func (b *Builder) Prepare(raws ...interface{}) ([]string, error) {
 	for _, launchDevice := range b.config.BlockDevices.LaunchMappings {
 		if launchDevice.DeviceName == b.config.RootDevice.SourceDeviceName {
 			foundRootVolume = true
+			if launchDevice.OmitFromArtifact {
+				errs = packer.MultiErrorAppend(errs, fmt.Errorf("You cannot set \"omit_from_artifact\": \"true\" for the root volume."))
+			}
 		}
 	}
 
@@ -243,7 +246,8 @@ func (b *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (pack
 			EnableAMIENASupport:      b.config.AMIENASupport,
 		},
 		&StepSnapshotVolumes{
-			LaunchDevices: launchDevices,
+			LaunchDevices:   launchDevices,
+			SnapshotOmitMap: b.config.GetOmissions(),
 		},
 		&awscommon.StepDeregisterAMI{
 			AccessConfig:        &b.config.AccessConfig,
@@ -259,6 +263,7 @@ func (b *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (pack
 			EnableAMISriovNetSupport: b.config.AMISriovNetSupport,
 			EnableAMIENASupport:      b.config.AMIENASupport,
 			Architecture:             b.config.Architecture,
+			LaunchOmitMap:            b.config.GetOmissions(),
 		},
 		&awscommon.StepAMIRegionCopy{
 			AccessConfig:      &b.config.AccessConfig,

builder/amazon/ebssurrogate/step_register_ami.go

@@ -20,6 +20,7 @@ type StepRegisterAMI struct {
 	EnableAMISriovNetSupport bool
 	Architecture             string
 	image                    *ec2.Image
+	LaunchOmitMap            map[string]bool
 }
 
 func (s *StepRegisterAMI) Run(ctx context.Context, state multistep.StateBag) multistep.StepAction {
@@ -126,6 +127,11 @@ func (s *StepRegisterAMI) combineDevices(snapshotIds map[string]string) []*ec2.B
 	// the same name in ami_block_device_mappings, except for the
 	// one designated as the root device in ami_root_device
 	for _, device := range s.LaunchDevices {
+		// Skip devices we've flagged for omission
+		omit, ok := s.LaunchOmitMap[*device.DeviceName]
+		if ok && omit {
+			continue
+		}
 		snapshotId, ok := snapshotIds[*device.DeviceName]
 		if ok {
 			device.Ebs.SnapshotId = aws.String(snapshotId)

builder/amazon/ebssurrogate/step_snapshot_volumes.go

@@ -18,8 +18,9 @@ import (
 // Produces:
 //   snapshot_ids map[string]string - IDs of the created snapshots
 type StepSnapshotVolumes struct {
-	LaunchDevices []*ec2.BlockDeviceMapping
-	snapshotIds   map[string]string
+	LaunchDevices   []*ec2.BlockDeviceMapping
+	snapshotIds     map[string]string
+	SnapshotOmitMap map[string]bool
 }
 
 func (s *StepSnapshotVolumes) snapshotVolume(ctx context.Context, deviceName string, state multistep.StateBag) error {
@@ -64,6 +65,12 @@ func (s *StepSnapshotVolumes) Run(ctx context.Context, state multistep.StateBag)
 	var wg sync.WaitGroup
 	var errs *multierror.Error
 	for _, device := range s.LaunchDevices {
+		// Skip devices we've flagged for omission
+		omit, ok := s.SnapshotOmitMap[*device.DeviceName]
+		if ok && omit {
+			continue
+		}
+
 		wg.Add(1)
 		go func(device *ec2.BlockDeviceMapping) {
 			defer wg.Done()

website/source/docs/builders/amazon-ebssurrogate.html.md.erb

@@ -252,6 +252,14 @@ builder.
     new AMI, the instance automatically launches with these additional volumes,
     and will restore them from snapshots taken from the source instance.
 
+    In addition to the fields available in ami_block_device_mappings, you may
+    optionally use the following field:
+        - "omit_from_artifact" (boolean) - If true, this block device will not
+        be snapshotted and the created AMI will not contain block device mapping
+        information for this volume. If false, the block device will be mapped
+        into the final created AMI. Set this option to true if you need a block
+        device mounted in the surrogate AMI but not in the final created AMI.
+
 -   `mfa_code` (string) - The MFA
     [TOTP](https://en.wikipedia.org/wiki/Time-based_One-time_Password_Algorithm)
     code. This should probably be a user variable since it changes all the