builder/amazon-ebs: Clean up orphan volumes

Fixes #1783

builder/amazon/common/block_device.go

@@ -42,7 +42,7 @@ func buildBlockDevices(b []BlockDevice) []*ec2.BlockDeviceMapping {
 		// You cannot specify Encrypted if you specify a Snapshot ID
 		if blockDevice.SnapshotId != "" {
 			ebsBlockDevice.SnapshotID = &blockDevice.SnapshotId
-		} else {
+		} else if blockDevice.Encrypted {
 			ebsBlockDevice.Encrypted = &blockDevice.Encrypted
 		}
 

builder/amazon/ebs/builder.go

@@ -99,6 +99,9 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 			CommConfig:       &b.config.RunConfig.Comm,
 			VpcId:            b.config.VpcId,
 		},
+		&stepCleanupVolumes{
+			BlockDevices: b.config.BlockDevices,
+		},
 		&awscommon.StepRunSourceInstance{
 			Debug:                    b.config.PackerDebug,
 			ExpectedRootDevice:       "ebs",

builder/amazon/ebs/step_cleanup_volumes.go

@@ -0,0 +1,117 @@
+package ebs
+
+import (
+	"fmt"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/service/ec2"
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/builder/amazon/common"
+	"github.com/mitchellh/packer/packer"
+)
+
+// stepCleanupVolumes cleans up any orphaned volumes that were not designated to
+// remain after termination of the instance. These volumes are typically ones
+// that are marked as "delete on terminate:false" in the source_ami of a build.
+type stepCleanupVolumes struct {
+	BlockDevices common.BlockDevices
+}
+
+func (s *stepCleanupVolumes) Run(state multistep.StateBag) multistep.StepAction {
+	// stepCleanupVolumes is for Cleanup only
+	return multistep.ActionContinue
+}
+
+func (s *stepCleanupVolumes) Cleanup(state multistep.StateBag) {
+	ec2conn := state.Get("ec2").(*ec2.EC2)
+	instanceRaw := state.Get("instance")
+	var instance *ec2.Instance
+	if instanceRaw != nil {
+		instance = instanceRaw.(*ec2.Instance)
+	}
+	ui := state.Get("ui").(packer.Ui)
+	amisRaw := state.Get("amis")
+	if amisRaw == nil {
+		ui.Say("No AMIs to cleanup")
+		return
+	}
+
+	if instance == nil {
+		ui.Say("No volumes to clean up, skipping")
+		return
+	}
+
+	ui.Say("Cleaning up any extra volumes...")
+
+	save := make(map[string]bool)
+	for _, b := range s.BlockDevices.AMIMappings {
+		if !b.DeleteOnTermination {
+			save[b.DeviceName] = true
+		}
+	}
+
+	for _, b := range s.BlockDevices.LaunchMappings {
+		if !b.DeleteOnTermination {
+			save[b.DeviceName] = true
+		}
+	}
+
+	// Collect Volume information from the cached Instance as a map of volume-id
+	// to device name, to compare with save list above
+	var vl []*string
+	volList := make(map[string]string)
+	for _, bdm := range instance.BlockDeviceMappings {
+		if bdm.EBS != nil {
+			vl = append(vl, bdm.EBS.VolumeID)
+			volList[*bdm.EBS.VolumeID] = *bdm.DeviceName
+		}
+	}
+
+	// Using the volume list from the cached Instance, check with AWS for up to
+	// date information on them
+	resp, err := ec2conn.DescribeVolumes(&ec2.DescribeVolumesInput{
+		Filters: []*ec2.Filter{
+			&ec2.Filter{
+				Name:   aws.String("volume-id"),
+				Values: vl,
+			},
+		},
+	})
+
+	if err != nil {
+		ui.Say(fmt.Sprintf("Error describing volumes: %s", err))
+		return
+	}
+
+	// If any of the returned volumes are in a "deleting" stage or otherwise not
+	// available, remove them from the list of volumes
+	for _, v := range resp.Volumes {
+		if v.State != nil && *v.State != "available" {
+			delete(volList, *v.VolumeID)
+		}
+	}
+
+	if len(resp.Volumes) == 0 {
+		ui.Say("No volumes to clean up, skipping")
+		return
+	}
+
+	// Filter out any devices marked for saving
+	for saveName, _ := range save {
+		for volKey, volName := range volList {
+			if volName == saveName {
+				delete(volList, volKey)
+			}
+		}
+	}
+
+	// Destroy remaining volumes
+	for k, _ := range volList {
+		ui.Say(fmt.Sprintf("Destroying volume (%s)...", k))
+		_, err := ec2conn.DeleteVolume(&ec2.DeleteVolumeInput{VolumeID: aws.String(k)})
+		if err != nil {
+			ui.Say(fmt.Sprintf("Error deleting volume: %s", k))
+		}
+
+	}
+}