builder/virtualbox: http server for local files

builder/virtualbox/builder.go

@@ -26,6 +26,9 @@ type config struct {
 	BootCommand    []string      `mapstructure:"boot_command"`
 	BootWait       time.Duration ``
 	GuestOSType    string        `mapstructure:"guest_os_type"`
+	HTTPDir        string        `mapstructure:"http_directory"`
+	HTTPPortMin    uint          `mapstructure:"http_port_min"`
+	HTTPPortMax    uint          `mapstructure:"http_port_max"`
 	ISOMD5         string        `mapstructure:"iso_md5"`
 	ISOUrl         string        `mapstructure:"iso_url"`
 	OutputDir      string        `mapstructure:"output_directory"`
@@ -47,6 +50,14 @@ func (b *Builder) Prepare(raw interface{}) error {
 		b.config.GuestOSType = "Other"
 	}
 
+	if b.config.HTTPPortMin == 0 {
+		b.config.HTTPPortMin = 8000
+	}
+
+	if b.config.HTTPPortMax == 0 {
+		b.config.HTTPPortMax = 9000
+	}
+
 	if b.config.OutputDir == "" {
 		b.config.OutputDir = "virtualbox"
 	}
@@ -69,6 +80,10 @@ func (b *Builder) Prepare(raw interface{}) error {
 
 	errs := make([]error, 0)
 
+	if b.config.HTTPPortMin > b.config.HTTPPortMax {
+		errs = append(errs, errors.New("http_port_min must be less than http_port_max"))
+	}
+
 	if b.config.ISOMD5 == "" {
 		errs = append(errs, errors.New("Due to large file sizes, an iso_md5 is required"))
 	} else {
@@ -141,6 +156,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) packer
 	steps := []multistep.Step{
 		new(stepDownloadISO),
 		new(stepPrepareOutputDir),
+		new(stepHTTPServer),
 		new(stepSuppressMessages),
 		new(stepCreateVM),
 		new(stepCreateDisk),

builder/virtualbox/builder_test.go

@@ -74,6 +74,34 @@ func TestBuilderPrepare_BootWait(t *testing.T) {
 	}
 }
 
+func TestBuilderPrepare_HTTPPort(t *testing.T) {
+	var b Builder
+	config := testConfig()
+
+	// Bad
+	config["http_port_min"] = 1000
+	config["http_port_max"] = 500
+	err := b.Prepare(config)
+	if err == nil {
+		t.Fatal("should have error")
+	}
+
+	// Bad
+	config["http_port_min"] = -500
+	err = b.Prepare(config)
+	if err == nil {
+		t.Fatal("should have error")
+	}
+
+	// Good
+	config["http_port_min"] = 500
+	config["http_port_max"] = 1000
+	err = b.Prepare(config)
+	if err != nil {
+		t.Fatalf("should not have error: %s", err)
+	}
+}
+
 func TestBuilderPrepare_ISOMD5(t *testing.T) {
 	var b Builder
 	config := testConfig()

builder/virtualbox/step_http_server.go

@@ -0,0 +1,68 @@
+package virtualbox
+
+import (
+	"fmt"
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+	"log"
+	"math/rand"
+	"net"
+	"net/http"
+)
+
+// This step creates and runs the HTTP server that is serving the files
+// specified by the 'http_files` configuration parameter in the template.
+//
+// Uses:
+//   config *config
+//   ui     packer.Ui
+//
+// Produces:
+//   http_port int - The port the HTTP server started on.
+type stepHTTPServer struct {
+	l net.Listener
+}
+
+func (s *stepHTTPServer) Run(state map[string]interface{}) multistep.StepAction {
+	config := state["config"].(*config)
+	ui := state["ui"].(packer.Ui)
+
+	var httpPort uint = 0
+	if config.HTTPDir == "" {
+		state["http_port"] = httpPort
+		return multistep.ActionContinue
+	}
+
+	// Find an available TCP port for our HTTP server
+	var httpAddr string
+	portRange := int(config.HTTPPortMax - config.HTTPPortMin)
+	for {
+		var err error
+		httpPort = uint(rand.Intn(portRange)) + config.HTTPPortMin
+		httpAddr = fmt.Sprintf(":%d", httpPort)
+		log.Printf("Trying port: %d", httpPort)
+		s.l, err = net.Listen("tcp", httpAddr)
+		if err == nil {
+			break
+		}
+	}
+
+	ui.Say(fmt.Sprintf("Starting HTTP server on port %d", httpPort))
+
+	// Start the HTTP server and run it in the background
+	fileServer := http.FileServer(http.Dir(config.HTTPDir))
+	server := &http.Server{Addr: httpAddr, Handler: fileServer}
+	go server.Serve(s.l)
+
+	// Save the address into the state so it can be accessed in the future
+	state["http_port"] = httpPort
+
+	return multistep.ActionContinue
+}
+
+func (s *stepHTTPServer) Cleanup(map[string]interface{}) {
+	if s.l != nil {
+		// Close the listener so that the HTTP server stops
+		s.l.Close()
+	}
+}