builder/amazon/chroot: step to snapshot the root image

builder/amazon/chroot/builder.go

@@ -143,6 +143,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		&StepCopyFiles{},
 		&StepChrootProvision{},
 		&StepEarlyCleanup{},
+		&StepSnapshot{},
 	}
 
 	// Run!

builder/amazon/chroot/step_snapshot.go

@@ -0,0 +1,87 @@
+package chroot
+
+import (
+	"errors"
+	"fmt"
+	"github.com/mitchellh/goamz/ec2"
+	"github.com/mitchellh/multistep"
+	awscommon "github.com/mitchellh/packer/builder/amazon/common"
+	"github.com/mitchellh/packer/packer"
+)
+
+// StepSnapshot creates a snapshot of the created volume.
+//
+// Produces:
+//   snapshot_id string - ID of the created snapshot
+type StepSnapshot struct {
+	snapshotId string
+}
+
+func (s *StepSnapshot) Run(state map[string]interface{}) multistep.StepAction {
+	ec2conn := state["ec2"].(*ec2.EC2)
+	ui := state["ui"].(packer.Ui)
+	volumeId := state["volume_id"].(string)
+
+	ui.Say("Creating snapshot...")
+	createSnapResp, err := ec2conn.CreateSnapshot(volumeId, "")
+	if err != nil {
+		err := fmt.Errorf("Error creating snapshot: %s", err)
+		state["error"] = err
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	// Set the snapshot ID so we can delete it later
+	s.snapshotId = createSnapResp.Id
+	ui.Message(fmt.Sprintf("Snapshot ID: %s", s.snapshotId))
+
+	// Wait for the snapshot to be ready
+	stateChange := awscommon.StateChangeConf{
+		Conn:      ec2conn,
+		Pending:   []string{"pending"},
+		StepState: state,
+		Target:    "completed",
+		Refresh: func() (interface{}, string, error) {
+			resp, err := ec2conn.Snapshots([]string{s.snapshotId}, ec2.NewFilter())
+			if err != nil {
+				return nil, "", err
+			}
+
+			if len(resp.Snapshots) == 0 {
+				return nil, "", errors.New("No snapshots found.")
+			}
+
+			return nil, resp.Snapshots[0].Status, nil
+		},
+	}
+
+	_, err = awscommon.WaitForState(&stateChange)
+	if err != nil {
+		err := fmt.Errorf("Error waiting for snapshot: %s", err)
+		state["error"] = err
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	state["snapshot_id"] = s.snapshotId
+	return multistep.ActionContinue
+}
+
+func (s *StepSnapshot) Cleanup(state map[string]interface{}) {
+	if s.snapshotId == "" {
+		return
+	}
+
+	_, cancelled := state[multistep.StateCancelled]
+	_, halted := state[multistep.StateHalted]
+
+	if cancelled || halted {
+		ec2conn := state["ec2"].(*ec2.EC2)
+		ui := state["ui"].(packer.Ui)
+		ui.Say("Removing snapshot since we cancelled or halted...")
+		_, err := ec2conn.DeleteSnapshots([]string{s.snapshotId})
+		if err != nil {
+			ui.Error(fmt.Sprintf("Error: %s", err))
+		}
+	}
+}