builder/digitalocean: use text/template for the snapshot name

builder/digitalocean/builder.go

@@ -4,6 +4,7 @@
 package digitalocean
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"github.com/mitchellh/mapstructure"
@@ -11,12 +12,18 @@ import (
 	"github.com/mitchellh/packer/builder/common"
 	"github.com/mitchellh/packer/packer"
 	"log"
+	"strconv"
+	"text/template"
 	"time"
 )
 
 // The unique id for the builder
 const BuilderId = "pearkes.digitalocean"
 
+type snapshotNameData struct {
+	CreateTime string
+}
+
 // Configuration tells the builder the credentials
 // to use while communicating with DO and describes the image
 // you are creating
@@ -27,7 +34,7 @@ type config struct {
 	SizeID   uint   `mapstructure:"size_id"`
 	ImageID  uint   `mapstructure:"image_id"`
 
-	SnapshotName string `mapstructure:"snapshot_name"`
+	SnapshotName string
 	SSHUsername  string `mapstructure:"ssh_username"`
 	SSHPort      uint   `mapstructure:"ssh_port"`
 	SSHTimeout   time.Duration
@@ -35,6 +42,7 @@ type config struct {
 
 	PackerDebug bool `mapstructure:"packer_debug"`
 
+	RawSnapshotName string `mapstructure:"snapshot_name"`
 	RawSSHTimeout   string `mapstructure:"ssh_timeout"`
 	RawEventDelay   string `mapstructure:"event_delay"`
 }
@@ -80,9 +88,9 @@ func (b *Builder) Prepare(raws ...interface{}) error {
 		b.config.SSHPort = 22
 	}
 
-	if b.config.SnapshotName == "" {
+	if b.config.RawSnapshotName == "" {
 		// Default to packer-{{ unix timestamp (utc) }}
-		b.config.SnapshotName = "packer-{{.CreateTime}}"
+		b.config.RawSnapshotName = "packer-{{.CreateTime}}"
 	}
 
 	if b.config.RawSSHTimeout == "" {
@@ -121,6 +129,15 @@ func (b *Builder) Prepare(raws ...interface{}) error {
 	}
 	b.config.EventDelay = delay
 
+	// Parse the name of the snapshot
+	snapNameBuf := new(bytes.Buffer)
+	tData := snapshotNameData{
+		strconv.FormatInt(time.Now().UTC().Unix(), 10),
+	}
+	t := template.Must(template.New("snapshot").Parse(b.config.RawSnapshotName))
+	t.Execute(snapNameBuf, tData)
+	b.config.SnapshotName = snapNameBuf.String()
+
 	if len(errs) > 0 {
 		return &packer.MultiError{errs}
 	}

builder/digitalocean/builder_test.go

@@ -2,6 +2,7 @@ package digitalocean
 
 import (
 	"github.com/mitchellh/packer/packer"
+	"strconv"
 	"testing"
 )
 
@@ -256,14 +257,35 @@ func TestBuilderPrepare_SnapshotName(t *testing.T) {
 	var b Builder
 	config := testConfig()
 
-	// Test set
-	config["snapshot_name"] = "foo"
+	// Test default
 	err := b.Prepare(config)
 	if err != nil {
 		t.Fatalf("should not have error: %s", err)
 	}
 
-	if b.config.SnapshotName != "foo" {
-		t.Errorf("invalid: %s", b.config.SnapshotName)
+	if b.config.RawSnapshotName != "packer-{{.CreateTime}}" {
+		t.Errorf("invalid: %d", b.config.RawSnapshotName)
+	}
+
+	// Test set
+	config["snapshot_name"] = "foobarbaz"
+	b = Builder{}
+	err = b.Prepare(config)
+	if err != nil {
+		t.Fatalf("should not have error: %s", err)
 	}
+
+	// Test set with template
+	config["snapshot_name"] = "{{.CreateTime}}"
+	b = Builder{}
+	err = b.Prepare(config)
+	if err != nil {
+		t.Fatalf("should not have error: %s", err)
+	}
+
+	_, err = strconv.ParseInt(b.config.SnapshotName, 0, 0)
+	if err != nil {
+		t.Fatalf("failed to parse int in template: %s", err)
+	}
+
 }

builder/digitalocean/step_snapshot.go

 package digitalocean
 
 import (
+	"fmt"
 	"github.com/mitchellh/multistep"
 	"github.com/mitchellh/packer/packer"
 )
@@ -13,7 +14,7 @@ func (s *stepSnapshot) Run(state map[string]interface{}) multistep.StepAction {
 	c := state["config"].(config)
 	dropletId := state["droplet_id"].(uint)
 
-	ui.Say("Creating snapshot...")
+	ui.Say(fmt.Sprintf("Creating snapshot: %v", c.SnapshotName))
 
 	err := client.CreateSnapshot(dropletId, c.SnapshotName)