post-processor/vagrant: compile the output path

post-processor/vagrant/aws.go

@@ -12,7 +12,7 @@ import (
 )
 
 type AWSBoxConfig struct {
-	OutputPath string `mapstructure:"output"`
+	OutputPath          string `mapstructure:"output"`
 	VagrantfileTemplate string `mapstructure:"vagrantfile_template"`
 }
 
@@ -48,6 +48,12 @@ func (p *AWSBoxPostProcessor) PostProcess(ui packer.Ui, artifact packer.Artifact
 		tplData.Images[parts[0]] = parts[1]
 	}
 
+	// Compile the output path
+	outputPath, err := ProcessOutputPath(p.config.OutputPath, "aws", artifact)
+	if err != nil {
+		return nil, err
+	}
+
 	// Create a temporary directory for us to build the contents of the box in
 	dir, err := ioutil.TempDir("", "packer")
 	if err != nil {
@@ -89,11 +95,11 @@ func (p *AWSBoxPostProcessor) PostProcess(ui packer.Ui, artifact packer.Artifact
 	}
 
 	// Compress the directory to the given output path
-	if err := DirToBox(p.config.OutputPath, dir); err != nil {
+	if err := DirToBox(outputPath, dir); err != nil {
 		return nil, err
 	}
 
-	return NewArtifact("aws", p.config.OutputPath), nil
+	return NewArtifact("aws", outputPath), nil
 }
 
 var defaultAWSVagrantfile = `

post-processor/vagrant/util.go

@@ -2,13 +2,23 @@ package vagrant
 
 import (
 	"archive/tar"
+	"bytes"
 	"compress/gzip"
 	"encoding/json"
+	"github.com/mitchellh/packer/packer"
 	"io"
 	"os"
 	"path/filepath"
+	"text/template"
 )
 
+// OutputPathTemplate is the structure that is availalable within the
+// OutputPath variables.
+type OutputPathTemplate struct {
+	ArtifactId string
+	Provider   string
+}
+
 // DirToBox takes the directory and compresses it into a Vagrant-compatible
 // box. This function does not perform checks to verify that dir is
 // actually a proper box. This is an expected precondition.
@@ -62,6 +72,25 @@ func DirToBox(dst, dir string) error {
 	return filepath.Walk(dir, tarWalk)
 }
 
+// ProcessOutputPath takes an output path template and executes it,
+// replacing variables with their respective values.
+func ProcessOutputPath(path string, provider string, artifact packer.Artifact) (string, error) {
+	var buf bytes.Buffer
+
+	tplData := &OutputPathTemplate{
+		ArtifactId: artifact.Id(),
+		Provider:   provider,
+	}
+
+	t, err := template.New("output").Parse(path)
+	if err != nil {
+		return "", err
+	}
+
+	err = t.Execute(&buf, tplData)
+	return buf.String(), err
+}
+
 // WriteMetadata writes the "metadata.json" file for a Vagrant box.
 func WriteMetadata(dir string, contents interface{}) error {
 	f, err := os.Create(filepath.Join(dir, "metadata.json"))

post-processor/vagrant/virtualbox.go

@@ -37,6 +37,12 @@ func (p *VBoxBoxPostProcessor) PostProcess(ui packer.Ui, artifact packer.Artifac
 	// TODO(mitchellh): Actually parse the base mac address
 	tplData := &VBoxVagrantfileTemplate{}
 
+	// Compile the output path
+	outputPath, err := ProcessOutputPath(p.config.OutputPath, "aws", artifact)
+	if err != nil {
+		return nil, err
+	}
+
 	// Create a temporary directory for us to build the contents of the box in
 	dir, err := ioutil.TempDir("", "packer")
 	if err != nil {
@@ -99,11 +105,11 @@ func (p *VBoxBoxPostProcessor) PostProcess(ui packer.Ui, artifact packer.Artifac
 
 	// Compress the directory to the given output path
 	ui.Message(fmt.Sprintf("Compressing box..."))
-	if err := DirToBox(p.config.OutputPath, dir); err != nil {
+	if err := DirToBox(outputPath, dir); err != nil {
 		return nil, err
 	}
 
-	return NewArtifact("virtualbox", p.config.OutputPath), nil
+	return NewArtifact("virtualbox", outputPath), nil
 }
 
 var defaultVBoxVagrantfile = `