Merge pull request #2556 from mitchellh/b-2414

Add interpolation for .BuildName in compress output filename

post-processor/compress/post-processor.go

@@ -55,9 +55,12 @@ func (p *PostProcessor) Configure(raws ...interface{}) error {
 		Interpolate:        true,
 		InterpolateContext: &p.config.ctx,
 		InterpolateFilter: &interpolate.RenderFilter{
-			Exclude: []string{},
+			Exclude: []string{"output"},
 		},
 	}, raws...)
+	if err != nil {
+		return err
+	}
 
 	errs := new(packer.MultiError)
 
@@ -67,16 +70,7 @@ func (p *PostProcessor) Configure(raws ...interface{}) error {
 	}
 
 	if p.config.OutputPath == "" {
-		p.config.OutputPath = "packer_{{.BuildName}}_{{.Provider}}"
-	}
-
-	if err = interpolate.Validate(p.config.OutputPath, &p.config.ctx); err != nil {
-		errs = packer.MultiErrorAppend(
-			errs, fmt.Errorf("Error parsing target template: %s", err))
-	}
-
-	templates := map[string]*string{
-		"output": &p.config.OutputPath,
+		p.config.OutputPath = "packer_{{.BuildName}}_{{.BuilderType}}"
 	}
 
 	if p.config.CompressionLevel > pgzip.BestCompression {
@@ -89,17 +83,9 @@ func (p *PostProcessor) Configure(raws ...interface{}) error {
 		p.config.CompressionLevel = pgzip.DefaultCompression
 	}
 
-	for key, ptr := range templates {
-		if *ptr == "" {
-			errs = packer.MultiErrorAppend(
-				errs, fmt.Errorf("%s must be set", key))
-		}
-
-		*ptr, err = interpolate.Render(p.config.OutputPath, &p.config.ctx)
-		if err != nil {
-			errs = packer.MultiErrorAppend(
-				errs, fmt.Errorf("Error processing %s: %s", key, err))
-		}
+	if err = interpolate.Validate(p.config.OutputPath, &p.config.ctx); err != nil {
+		errs = packer.MultiErrorAppend(
+			errs, fmt.Errorf("Error parsing target template: %s", err))
 	}
 
 	p.config.detectFromFilename()
@@ -113,7 +99,19 @@ func (p *PostProcessor) Configure(raws ...interface{}) error {
 
 func (p *PostProcessor) PostProcess(ui packer.Ui, artifact packer.Artifact) (packer.Artifact, bool, error) {
 
-	target := p.config.OutputPath
+	// These are extra variables that will be made available for interpolation.
+	p.config.ctx.Data = map[string]string{
+		"BuildName":   p.config.PackerBuildName,
+		"BuilderType": p.config.PackerBuilderType,
+	}
+
+	target, err := interpolate.Render(p.config.OutputPath, &p.config.ctx)
+	if err != nil {
+		return nil, false, fmt.Errorf("Error interpolating output value: %s", err)
+	} else {
+		fmt.Println(target)
+	}
+
 	keep := p.config.KeepInputArtifact
 	newArtifact := &Artifact{Path: target}
 

post-processor/compress/post-processor_test.go

@@ -150,6 +150,37 @@ func TestCompressOptions(t *testing.T) {
 	}
 }
 
+func TestCompressInterpolation(t *testing.T) {
+	const config = `
+	{
+	    "post-processors": [
+	        {
+	            "type": "compress",
+	            "output": "{{ build_name}}-{{ .BuildName }}-{{.BuilderType}}.gz"
+	        }
+	    ]
+	}
+	`
+
+	artifact := testArchive(t, config)
+	defer artifact.Destroy()
+
+	// You can interpolate using the .BuildName variable or build_name global
+	// function. We'll check both.
+	filename := "chocolate-vanilla-file.gz"
+	archive, err := os.Open(filename)
+	if err != nil {
+		t.Fatalf("Unable to read %s: %s", filename, err)
+	}
+
+	gzipReader, _ := gzip.NewReader(archive)
+	data, _ := ioutil.ReadAll(gzipReader)
+
+	if string(data) != expectedFileContents {
+		t.Errorf("Expected:\n%s\nFound:\n%s\n", expectedFileContents, data)
+	}
+}
+
 // Test Helpers
 
 func setup(t *testing.T) (packer.Ui, packer.Artifact, error) {
@@ -201,6 +232,13 @@ func testArchive(t *testing.T, config string) packer.Artifact {
 
 	compressor := PostProcessor{}
 	compressor.Configure(tpl.PostProcessors[0][0].Config)
+
+	// I get the feeling these should be automatically available somewhere, but
+	// some of the post-processors construct this manually.
+	compressor.config.ctx.BuildName = "chocolate"
+	compressor.config.PackerBuildName = "vanilla"
+	compressor.config.PackerBuilderType = "file"
+
 	artifactOut, _, err := compressor.PostProcess(ui, artifact)
 	if err != nil {
 		t.Fatalf("Failed to compress artifact: %s", err)

website/source/docs/post-processors/compress.html.markdown

@@ -15,10 +15,11 @@ VMware or VirtualBox) and compresses the artifact into a single archive.
 
 ## Configuration
 
-### Required:
+### Optional:
 
-You must specify the output filename. The archive format is derived from the
-filename.
+By default, packer will build archives in `.tar.gz` format with the following
+filename: `packer_{{.BuildName}}_{{.BuilderType}}`. If you want to change this
+you will need to specify the `output` option.
 
 -   `output` (string) - The path to save the compressed archive. The archive
     format is inferred from the filename. E.g. `.tar.gz` will be a
@@ -26,13 +27,9 @@ filename.
     detected packer defaults to `.tar.gz` behavior but will not change
     the filename.
 
-If you are executing multiple builders in parallel you should make sure `output`
-is unique for each one. For example `packer_{{.BuildName}}_{{.Provider}}.zip`.
-
-### Optional:
-
-If you want more control over how the archive is created you can specify the
-following settings:
+    You can use `{{.BuildName}}` and `{{.BuilderType}}` in your output path.
+    If you are executing multiple builders in parallel you should make sure
+    `output` is unique for each one. For example `packer_{{.BuildName}}.zip`.
 
 -   `compression_level` (integer) - Specify the compression level, for
     algorithms that support it, from 1 through 9 inclusive. Typically higher
@@ -61,14 +58,14 @@ configuration:
 ``` {.json}
 {
   "type": "compress",
-  "output": "archive.zip"
+  "output": "{{.BuildName}}_bundle.zip"
 }
 ```
 
 ``` {.json}
 {
   "type": "compress",
-  "output": "archive.gz",
+  "output": "log_{{.BuildName}}.gz",
   "compression": 9
 }
 ```