[post-processor/compress] Add support for compress.

This commit adds support for a post-processor that produces a compressed
archive that can be uploaded to an OpenStack cluster through either
the Horizon web interface or Glance.

plugin/post-processor-compress/main.go

+package main
+
+import (
+	"github.com/mitchellh/packer/packer/plugin"
+	"github.com/mitchellh/packer/post-processor/compress"
+)
+
+func main() {
+	server, err := plugin.Server()
+	if err != nil {
+		panic(err)
+	}
+	server.RegisterPostProcessor(new(compress.PostProcessor))
+	server.Serve()
+}

plugin/post-processor-compress/main_test.go

+package main

post-processor/compress/artifact.go

+package compress
+
+import (
+	"fmt"
+	"os"
+)
+
+const BuilderId = "johnbellone.compress"
+
+type Artifact struct {
+	Path     string
+	Provider string
+}
+
+func NewArtifact(provider, path string) *Artifact {
+	return &Artifact{
+		Path:     path,
+		Provider: provider,
+	}
+}
+
+func (*Artifact) BuilderId() string {
+	return BuilderId
+}
+
+func (self *Artifact) Id() string {
+	return ""
+}
+
+func (self *Artifact) Files() []string {
+	return []string{self.Path}
+}
+
+func (self *Artifact) String() string {
+	return fmt.Sprintf("'%s' compressing: %s", self.Provider, self.Path)
+}
+
+func (self *Artifact) Destroy() error {
+	return os.Remove(self.Path)
+}

post-processor/compress/artifact_test.go

+package compress
+
+import (
+	"github.com/mitchellh/packer/packer"
+	"testing"
+)
+
+func TestArtifact_ImplementsArtifact(t *testing.T) {
+	var raw interface{}
+	raw = &Artifact{}
+	if _, ok := raw.(packer.Artifact); !ok {
+		t.Fatalf("Artifact should be a Artifact!")
+	}
+}

post-processor/compress/post-processor.go

+package compress
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/mitchellh/packer/common"
+	"github.com/mitchellh/packer/packer"
+)
+
+type Config struct {
+	common.PackerConfig `mapstructure:",squash"`
+
+	OutputPath string `mapstructure:"output_path"`
+
+	tpl *packer.ConfigTemplate
+}
+
+type PostProcessor struct {
+	config Config
+}
+
+func (self *PostProcessor) Configure(raws ...interface{}) error {
+	_, err := common.DecodeConfig(&self.config, raws...)
+	if err != nil {
+		return err
+	}
+
+	self.config.tpl, err = packer.NewConfigTemplate()
+	if err != nil {
+		return err
+	}
+
+	templates := map[string]*string{
+		"output_path": &self.config.OutputPath,
+	}
+
+	errs := new(packer.MultiError)
+	for key, ptr := range templates {
+		if *ptr == "" {
+			errs = packer.MultiErrorAppend(
+				errs, fmt.Errorf("%s must be set", key))
+		}
+
+		*ptr, err = self.config.tpl.Process(*ptr, nil)
+		if err != nil {
+			errs = packer.MultiErrorAppend(
+				errs, fmt.Errorf("Error processing %s: %s", key, err))
+		}
+	}
+
+	if len(errs.Errors) > 0 {
+		return errs
+	}
+
+	return nil
+
+}
+
+func (self *PostProcessor) PostProcess(ui packer.Ui, artifact packer.Artifact) (packer.Artifact, bool, error) {
+	ui.Say(fmt.Sprintf("Creating archive for '%s'", artifact.BuilderId()))
+
+	// Create the compressed archive file at the appropriate OutputPath.
+	fw, err := os.Create(self.config.OutputPath)
+	if err != nil {
+		return nil, false, fmt.Errorf(
+			"Failed creating file for compressed archive: %s", self.config.OutputPath)
+	}
+	defer fw.Close()
+
+	gw := gzip.NewWriter(fw)
+	defer gw.Close()
+
+	// Iterate through all of the artifact's files and put them into the
+	// compressed archive using the tar/gzip writers.
+	for _, path := range artifact.Files() {
+		fi, err := os.Stat(path)
+		if err != nil {
+			return nil, false, fmt.Errorf(
+				"Failed stating file: %s", path)
+		}
+
+		target, _ := os.Readlink(path)
+		header, err := tar.FileInfoHeader(fi, target)
+		if err != nil {
+			return nil, false, fmt.Errorf(
+				"Failed creating archive header: %s", path)
+		}
+
+		tw := tar.NewWriter(gw)
+		defer tw.Close()
+
+		// Write the header first to the archive. This takes partial data
+		// from the FileInfo that is grabbed by running the stat command.
+		if err := tw.WriteHeader(header); err != nil {
+			return nil, false, fmt.Errorf(
+				"Failed writing archive header: %s", path)
+		}
+
+		// Open the target file for archiving and compressing.
+		fr, err := os.Open(path)
+		if err != nil {
+			return nil, false, fmt.Errorf(
+				"Failed opening file '%s' to write compressed archive.", path)
+		}
+		defer fr.Close()
+
+		if _, err = io.Copy(tw, fr); err != nil {
+			return nil, false, fmt.Errorf(
+				"Failed copying file to archive: %s", path)
+		}
+	}
+
+	return NewArtifact(artifact.BuilderId(), self.config.OutputPath), false, nil
+}

post-processor/compress/post-processor_test.go

+package compress
+
+import (
+	"github.com/mitchellh/packer/packer"
+	"testing"
+)