Merge pull request #715 from mitchellh/f-gce-builder

Google Compute Builder

builder/googlecompute/artifact.go

@@ -0,0 +1,39 @@
+package googlecompute
+
+import (
+	"fmt"
+	"log"
+)
+
+// Artifact represents a GCE image as the result of a Packer build.
+type Artifact struct {
+	imageName string
+	driver    Driver
+}
+
+// BuilderId returns the builder Id.
+func (*Artifact) BuilderId() string {
+	return BuilderId
+}
+
+// Destroy destroys the GCE image represented by the artifact.
+func (a *Artifact) Destroy() error {
+	log.Printf("Destroying image: %s", a.imageName)
+	errCh := a.driver.DeleteImage(a.imageName)
+	return <-errCh
+}
+
+// Files returns the files represented by the artifact.
+func (*Artifact) Files() []string {
+	return nil
+}
+
+// Id returns the GCE image name.
+func (a *Artifact) Id() string {
+	return a.imageName
+}
+
+// String returns the string representation of the artifact.
+func (a *Artifact) String() string {
+	return fmt.Sprintf("A disk image was created: %v", a.imageName)
+}

builder/googlecompute/artifact_test.go

@@ -0,0 +1,10 @@
+package googlecompute
+
+import (
+	"github.com/mitchellh/packer/packer"
+	"testing"
+)
+
+func TestArtifact_impl(t *testing.T) {
+	var _ packer.Artifact = new(Artifact)
+}

builder/googlecompute/builder.go

@@ -0,0 +1,100 @@
+// The googlecompute package contains a packer.Builder implementation that
+// builds images for Google Compute Engine.
+package googlecompute
+
+import (
+	"log"
+	"time"
+
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/common"
+	"github.com/mitchellh/packer/packer"
+)
+
+// The unique ID for this builder.
+const BuilderId = "packer.googlecompute"
+
+// Builder represents a Packer Builder.
+type Builder struct {
+	config *Config
+	runner multistep.Runner
+}
+
+// Prepare processes the build configuration parameters.
+func (b *Builder) Prepare(raws ...interface{}) ([]string, error) {
+	c, warnings, errs := NewConfig(raws...)
+	if errs != nil {
+		return warnings, errs
+	}
+	b.config = c
+
+	return warnings, nil
+}
+
+// Run executes a googlecompute Packer build and returns a packer.Artifact
+// representing a GCE machine image.
+func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packer.Artifact, error) {
+	driver, err := NewDriverGCE(
+		ui, b.config.ProjectId, b.config.clientSecrets, b.config.privateKeyBytes)
+	if err != nil {
+		return nil, err
+	}
+
+	// Set up the state.
+	state := new(multistep.BasicStateBag)
+	state.Put("config", b.config)
+	state.Put("driver", driver)
+	state.Put("hook", hook)
+	state.Put("ui", ui)
+
+	// Build the steps.
+	steps := []multistep.Step{
+		new(StepCreateSSHKey),
+		new(StepCreateInstance),
+		new(StepInstanceInfo),
+		&common.StepConnectSSH{
+			SSHAddress:     sshAddress,
+			SSHConfig:      sshConfig,
+			SSHWaitTimeout: 5 * time.Minute,
+		},
+		new(common.StepProvision),
+		new(StepUpdateGsutil),
+		new(StepCreateImage),
+		new(StepUploadImage),
+		new(StepRegisterImage),
+	}
+
+	// Run the steps.
+	if b.config.PackerDebug {
+		b.runner = &multistep.DebugRunner{
+			Steps:   steps,
+			PauseFn: common.MultistepDebugFn(ui),
+		}
+	} else {
+		b.runner = &multistep.BasicRunner{Steps: steps}
+	}
+	b.runner.Run(state)
+
+	// Report any errors.
+	if rawErr, ok := state.GetOk("error"); ok {
+		return nil, rawErr.(error)
+	}
+	if _, ok := state.GetOk("image_name"); !ok {
+		log.Println("Failed to find image_name in state. Bug?")
+		return nil, nil
+	}
+
+	artifact := &Artifact{
+		imageName: state.Get("image_name").(string),
+		driver:    driver,
+	}
+	return artifact, nil
+}
+
+// Cancel.
+func (b *Builder) Cancel() {
+	if b.runner != nil {
+		log.Println("Cancelling the step runner...")
+		b.runner.Cancel()
+	}
+}

builder/googlecompute/builder_test.go

@@ -0,0 +1 @@
+package googlecompute

builder/googlecompute/client_secrets.go

@@ -0,0 +1,32 @@
+package googlecompute
+
+import (
+	"encoding/json"
+	"io/ioutil"
+)
+
+// clientSecrets represents the client secrets of a GCE service account.
+type clientSecrets struct {
+	Web struct {
+		AuthURI     string `json:"auth_uri"`
+		ClientEmail string `json:"client_email"`
+		ClientId    string `json:"client_id"`
+		TokenURI    string `json:"token_uri"`
+	}
+}
+
+// loadClientSecrets loads the GCE client secrets file identified by path.
+func loadClientSecrets(path string) (*clientSecrets, error) {
+	var cs *clientSecrets
+	secretBytes, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	err = json.Unmarshal(secretBytes, &cs)
+	if err != nil {
+		return nil, err
+	}
+
+	return cs, nil
+}

builder/googlecompute/client_secrets_test.go

@@ -0,0 +1,31 @@
+package googlecompute
+
+import (
+	"io/ioutil"
+	"testing"
+)
+
+func testClientSecretsFile(t *testing.T) string {
+	tf, err := ioutil.TempFile("", "packer")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	defer tf.Close()
+
+	if _, err := tf.Write([]byte(testClientSecretsContent)); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	return tf.Name()
+}
+
+func TestLoadClientSecrets(t *testing.T) {
+	_, err := loadClientSecrets(testClientSecretsFile(t))
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+}
+
+// This is just some dummy data that doesn't actually work (it was revoked
+// a long time ago).
+const testClientSecretsContent = `{"web":{"auth_uri":"https://accounts.google.com/o/oauth2/auth","token_uri":"https://accounts.google.com/o/oauth2/token","client_email":"774313886706-eorlsj0r4eqkh5e7nvea5fuf59ifr873@developer.gserviceaccount.com","client_x509_cert_url":"https://www.googleapis.com/robot/v1/metadata/x509/774313886706-eorlsj0r4eqkh5e7nvea5fuf59ifr873@developer.gserviceaccount.com","client_id":"774313886706-eorlsj0r4eqkh5e7nvea5fuf59ifr873.apps.googleusercontent.com","auth_provider_x509_cert_url":"https://www.googleapis.com/oauth2/v1/certs"}}`

builder/googlecompute/config.go

@@ -0,0 +1,187 @@
+package googlecompute
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/mitchellh/packer/common"
+	"github.com/mitchellh/packer/packer"
+)
+
+// Config is the configuration structure for the GCE builder. It stores
+// both the publicly settable state as well as the privately generated
+// state of the config object.
+type Config struct {
+	common.PackerConfig `mapstructure:",squash"`
+
+	BucketName        string            `mapstructure:"bucket_name"`
+	ClientSecretsFile string            `mapstructure:"client_secrets_file"`
+	ImageName         string            `mapstructure:"image_name"`
+	ImageDescription  string            `mapstructure:"image_description"`
+	MachineType       string            `mapstructure:"machine_type"`
+	Metadata          map[string]string `mapstructure:"metadata"`
+	Network           string            `mapstructure:"network"`
+	Passphrase        string            `mapstructure:"passphrase"`
+	PrivateKeyFile    string            `mapstructure:"private_key_file"`
+	ProjectId         string            `mapstructure:"project_id"`
+	SourceImage       string            `mapstructure:"source_image"`
+	SSHUsername       string            `mapstructure:"ssh_username"`
+	SSHPort           uint              `mapstructure:"ssh_port"`
+	RawSSHTimeout     string            `mapstructure:"ssh_timeout"`
+	RawStateTimeout   string            `mapstructure:"state_timeout"`
+	Tags              []string          `mapstructure:"tags"`
+	Zone              string            `mapstructure:"zone"`
+
+	clientSecrets   *clientSecrets
+	instanceName    string
+	privateKeyBytes []byte
+	sshTimeout      time.Duration
+	stateTimeout    time.Duration
+	tpl             *packer.ConfigTemplate
+}
+
+func NewConfig(raws ...interface{}) (*Config, []string, error) {
+	c := new(Config)
+	md, err := common.DecodeConfig(c, raws...)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	c.tpl, err = packer.NewConfigTemplate()
+	if err != nil {
+		return nil, nil, err
+	}
+	c.tpl.UserVars = c.PackerUserVars
+
+	// Prepare the errors
+	errs := common.CheckUnusedConfig(md)
+
+	// Set defaults.
+	if c.Network == "" {
+		c.Network = "default"
+	}
+
+	if c.ImageDescription == "" {
+		c.ImageDescription = "Created by Packer"
+	}
+
+	if c.ImageName == "" {
+		c.ImageName = "packer-{{timestamp}}"
+	}
+
+	if c.MachineType == "" {
+		c.MachineType = "n1-standard-1"
+	}
+
+	if c.RawSSHTimeout == "" {
+		c.RawSSHTimeout = "5m"
+	}
+
+	if c.RawStateTimeout == "" {
+		c.RawStateTimeout = "5m"
+	}
+
+	if c.SSHUsername == "" {
+		c.SSHUsername = "root"
+	}
+
+	if c.SSHPort == 0 {
+		c.SSHPort = 22
+	}
+
+	// Process Templates
+	templates := map[string]*string{
+		"bucket_name":         &c.BucketName,
+		"client_secrets_file": &c.ClientSecretsFile,
+		"image_name":          &c.ImageName,
+		"image_description":   &c.ImageDescription,
+		"machine_type":        &c.MachineType,
+		"network":             &c.Network,
+		"passphrase":          &c.Passphrase,
+		"private_key_file":    &c.PrivateKeyFile,
+		"project_id":          &c.ProjectId,
+		"source_image":        &c.SourceImage,
+		"ssh_username":        &c.SSHUsername,
+		"ssh_timeout":         &c.RawSSHTimeout,
+		"state_timeout":       &c.RawStateTimeout,
+		"zone":                &c.Zone,
+	}
+
+	for n, ptr := range templates {
+		var err error
+		*ptr, err = c.tpl.Process(*ptr, nil)
+		if err != nil {
+			errs = packer.MultiErrorAppend(
+				errs, fmt.Errorf("Error processing %s: %s", n, err))
+		}
+	}
+
+	// Process required parameters.
+	if c.BucketName == "" {
+		errs = packer.MultiErrorAppend(
+			errs, errors.New("a bucket_name must be specified"))
+	}
+
+	if c.ClientSecretsFile == "" {
+		errs = packer.MultiErrorAppend(
+			errs, errors.New("a client_secrets_file must be specified"))
+	}
+
+	if c.PrivateKeyFile == "" {
+		errs = packer.MultiErrorAppend(
+			errs, errors.New("a private_key_file must be specified"))
+	}
+
+	if c.ProjectId == "" {
+		errs = packer.MultiErrorAppend(
+			errs, errors.New("a project_id must be specified"))
+	}
+
+	if c.SourceImage == "" {
+		errs = packer.MultiErrorAppend(
+			errs, errors.New("a source_image must be specified"))
+	}
+
+	if c.Zone == "" {
+		errs = packer.MultiErrorAppend(
+			errs, errors.New("a zone must be specified"))
+	}
+
+	// Process timeout settings.
+	sshTimeout, err := time.ParseDuration(c.RawSSHTimeout)
+	if err != nil {
+		errs = packer.MultiErrorAppend(
+			errs, fmt.Errorf("Failed parsing ssh_timeout: %s", err))
+	}
+	c.sshTimeout = sshTimeout
+
+	stateTimeout, err := time.ParseDuration(c.RawStateTimeout)
+	if err != nil {
+		errs = packer.MultiErrorAppend(
+			errs, fmt.Errorf("Failed parsing state_timeout: %s", err))
+	}
+	c.stateTimeout = stateTimeout
+
+	// Load the client secrets file.
+	cs, err := loadClientSecrets(c.ClientSecretsFile)
+	if err != nil {
+		errs = packer.MultiErrorAppend(
+			errs, fmt.Errorf("Failed parsing client secrets file: %s", err))
+	}
+	c.clientSecrets = cs
+
+	// Load the private key.
+	c.privateKeyBytes, err = processPrivateKeyFile(c.PrivateKeyFile, c.Passphrase)
+	if err != nil {
+		errs = packer.MultiErrorAppend(
+			errs, fmt.Errorf("Failed loading private key file: %s", err))
+	}
+
+	// Check for any errors.
+	if errs != nil && len(errs.Errors) > 0 {
+		return nil, nil, errs
+	}
+
+	return c, nil, nil
+}

builder/googlecompute/config_test.go

@@ -0,0 +1,176 @@
+package googlecompute
+
+import (
+	"testing"
+)
+
+func testConfig(t *testing.T) map[string]interface{} {
+	return map[string]interface{}{
+		"bucket_name":         "foo",
+		"client_secrets_file": testClientSecretsFile(t),
+		"private_key_file":    testPrivateKeyFile(t),
+		"project_id":          "hashicorp",
+		"source_image":        "foo",
+		"zone":                "us-east-1a",
+	}
+}
+
+func testConfigStruct(t *testing.T) *Config {
+	c, warns, errs := NewConfig(testConfig(t))
+	if len(warns) > 0 {
+		t.Fatalf("bad: %#v", len(warns))
+	}
+	if errs != nil {
+		t.Fatalf("bad: %#v", errs)
+	}
+
+	return c
+}
+
+func testConfigErr(t *testing.T, warns []string, err error, extra string) {
+	if len(warns) > 0 {
+		t.Fatalf("bad: %#v", warns)
+	}
+	if err == nil {
+		t.Fatalf("should error: %s", extra)
+	}
+}
+
+func testConfigOk(t *testing.T, warns []string, err error) {
+	if len(warns) > 0 {
+		t.Fatalf("bad: %#v", warns)
+	}
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+}
+
+func TestConfigPrepare(t *testing.T) {
+	cases := []struct {
+		Key   string
+		Value interface{}
+		Err   bool
+	}{
+		{
+			"unknown_key",
+			"bad",
+			true,
+		},
+
+		{
+			"bucket_name",
+			nil,
+			true,
+		},
+		{
+			"bucket_name",
+			"good",
+			false,
+		},
+
+		{
+			"client_secrets_file",
+			nil,
+			true,
+		},
+		{
+			"client_secrets_file",
+			testClientSecretsFile(t),
+			false,
+		},
+		{
+			"client_secrets_file",
+			"/tmp/i/should/not/exist",
+			true,
+		},
+
+		{
+			"private_key_file",
+			nil,
+			true,
+		},
+		{
+			"private_key_file",
+			testPrivateKeyFile(t),
+			false,
+		},
+		{
+			"private_key_file",
+			"/tmp/i/should/not/exist",
+			true,
+		},
+
+		{
+			"project_id",
+			nil,
+			true,
+		},
+		{
+			"project_id",
+			"foo",
+			false,
+		},
+
+		{
+			"source_image",
+			nil,
+			true,
+		},
+		{
+			"source_image",
+			"foo",
+			false,
+		},
+
+		{
+			"zone",
+			nil,
+			true,
+		},
+		{
+			"zone",
+			"foo",
+			false,
+		},
+
+		{
+			"ssh_timeout",
+			"SO BAD",
+			true,
+		},
+		{
+			"ssh_timeout",
+			"5s",
+			false,
+		},
+
+		{
+			"state_timeout",
+			"SO BAD",
+			true,
+		},
+		{
+			"state_timeout",
+			"5s",
+			false,
+		},
+	}
+
+	for _, tc := range cases {
+		raw := testConfig(t)
+
+		if tc.Value == nil {
+			delete(raw, tc.Key)
+		} else {
+			raw[tc.Key] = tc.Value
+		}
+
+		_, warns, errs := NewConfig(raw)
+
+		if tc.Err {
+			testConfigErr(t, warns, errs, tc.Key)
+		} else {
+			testConfigOk(t, warns, errs)
+		}
+	}
+}

builder/googlecompute/driver.go

@@ -0,0 +1,35 @@
+package googlecompute
+
+// Driver is the interface that has to be implemented to communicate
+// with GCE. The Driver interface exists mostly to allow a mock implementation
+// to be used to test the steps.
+type Driver interface {
+	// CreateImage creates an image with the given URL in Google Storage.
+	CreateImage(name, description, url string) <-chan error
+
+	// DeleteImage deletes the image with the given name.
+	DeleteImage(name string) <-chan error
+
+	// DeleteInstance deletes the given instance.
+	DeleteInstance(zone, name string) (<-chan error, error)
+
+	// GetNatIP gets the NAT IP address for the instance.
+	GetNatIP(zone, name string) (string, error)
+
+	// RunInstance takes the given config and launches an instance.
+	RunInstance(*InstanceConfig) (<-chan error, error)
+
+	// WaitForInstance waits for an instance to reach the given state.
+	WaitForInstance(state, zone, name string) <-chan error
+}
+
+type InstanceConfig struct {
+	Description string
+	Image       string
+	MachineType string
+	Metadata    map[string]string
+	Name        string
+	Network     string
+	Tags        []string
+	Zone        string
+}

builder/googlecompute/driver_gce.go

@@ -0,0 +1,309 @@
+package googlecompute
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"time"
+
+	"code.google.com/p/goauth2/oauth"
+	"code.google.com/p/goauth2/oauth/jwt"
+	"code.google.com/p/google-api-go-client/compute/v1beta16"
+	"github.com/mitchellh/packer/packer"
+)
+
+// driverGCE is a Driver implementation that actually talks to GCE.
+// Create an instance using NewDriverGCE.
+type driverGCE struct {
+	projectId string
+	service   *compute.Service
+	ui        packer.Ui
+}
+
+const DriverScopes string = "https://www.googleapis.com/auth/compute " +
+	"https://www.googleapis.com/auth/devstorage.full_control"
+
+func NewDriverGCE(ui packer.Ui, projectId string, c *clientSecrets, key []byte) (Driver, error) {
+	log.Printf("[INFO] Requesting token...")
+	log.Printf("[INFO]   -- Email: %s", c.Web.ClientEmail)
+	log.Printf("[INFO]   -- Scopes: %s", DriverScopes)
+	log.Printf("[INFO]   -- Private Key Length: %d", len(key))
+	log.Printf("[INFO]   -- Token URL: %s", c.Web.TokenURI)
+	jwtTok := jwt.NewToken(c.Web.ClientEmail, DriverScopes, key)
+	jwtTok.ClaimSet.Aud = c.Web.TokenURI
+	token, err := jwtTok.Assert(new(http.Client))
+	if err != nil {
+		return nil, err
+	}
+
+	transport := &oauth.Transport{
+		Config: &oauth.Config{
+			ClientId: c.Web.ClientId,
+			Scope:    DriverScopes,
+			TokenURL: c.Web.TokenURI,
+			AuthURL:  c.Web.AuthURI,
+		},
+		Token: token,
+	}
+
+	log.Printf("[INFO] Instantiating client...")
+	service, err := compute.New(transport.Client())
+	if err != nil {
+		return nil, err
+	}
+
+	return &driverGCE{
+		projectId: projectId,
+		service:   service,
+		ui:        ui,
+	}, nil
+}
+
+func (d *driverGCE) CreateImage(name, description, url string) <-chan error {
+	image := &compute.Image{
+		Description: description,
+		Name:        name,
+		RawDisk: &compute.ImageRawDisk{
+			ContainerType: "TAR",
+			Source:        url,
+		},
+		SourceType: "RAW",
+	}
+
+	errCh := make(chan error, 1)
+	op, err := d.service.Images.Insert(d.projectId, image).Do()
+	if err != nil {
+		errCh <- err
+	} else {
+		go waitForState(errCh, "DONE", d.refreshGlobalOp(op))
+	}
+
+	return errCh
+}
+
+func (d *driverGCE) DeleteImage(name string) <-chan error {
+	errCh := make(chan error, 1)
+	op, err := d.service.Images.Delete(d.projectId, name).Do()
+	if err != nil {
+		errCh <- err
+	} else {
+		go waitForState(errCh, "DONE", d.refreshGlobalOp(op))
+	}
+
+	return errCh
+}
+
+func (d *driverGCE) DeleteInstance(zone, name string) (<-chan error, error) {
+	op, err := d.service.Instances.Delete(d.projectId, zone, name).Do()
+	if err != nil {
+		return nil, err
+	}
+
+	errCh := make(chan error, 1)
+	go waitForState(errCh, "DONE", d.refreshZoneOp(zone, op))
+	return errCh, nil
+}
+
+func (d *driverGCE) GetNatIP(zone, name string) (string, error) {
+	instance, err := d.service.Instances.Get(d.projectId, zone, name).Do()
+	if err != nil {
+		return "", err
+	}
+
+	for _, ni := range instance.NetworkInterfaces {
+		if ni.AccessConfigs == nil {
+			continue
+		}
+
+		for _, ac := range ni.AccessConfigs {
+			if ac.NatIP != "" {
+				return ac.NatIP, nil
+			}
+		}
+	}
+
+	return "", nil
+}
+
+func (d *driverGCE) RunInstance(c *InstanceConfig) (<-chan error, error) {
+	// Get the zone
+	d.ui.Message(fmt.Sprintf("Loading zone: %s", c.Zone))
+	zone, err := d.service.Zones.Get(d.projectId, c.Zone).Do()
+	if err != nil {
+		return nil, err
+	}
+
+	// Get the image
+	d.ui.Message(fmt.Sprintf("Loading image: %s", c.Image))
+	image, err := d.getImage(c.Image)
+	if err != nil {
+		return nil, err
+	}
+
+	// Get the machine type
+	d.ui.Message(fmt.Sprintf("Loading machine type: %s", c.MachineType))
+	machineType, err := d.service.MachineTypes.Get(
+		d.projectId, zone.Name, c.MachineType).Do()
+	if err != nil {
+		return nil, err
+	}
+	// TODO(mitchellh): deprecation warnings
+
+	// Get the network
+	d.ui.Message(fmt.Sprintf("Loading network: %s", c.Network))
+	network, err := d.service.Networks.Get(d.projectId, c.Network).Do()
+	if err != nil {
+		return nil, err
+	}
+
+	// Build up the metadata
+	metadata := make([]*compute.MetadataItems, len(c.Metadata))
+	for k, v := range c.Metadata {
+		metadata = append(metadata, &compute.MetadataItems{
+			Key:   k,
+			Value: v,
+		})
+	}
+
+	// Create the instance information
+	instance := compute.Instance{
+		Description: c.Description,
+		Image:       image.SelfLink,
+		MachineType: machineType.SelfLink,
+		Metadata: &compute.Metadata{
+			Items: metadata,
+		},
+		Name: c.Name,
+		NetworkInterfaces: []*compute.NetworkInterface{
+			&compute.NetworkInterface{
+				AccessConfigs: []*compute.AccessConfig{
+					&compute.AccessConfig{
+						Name: "AccessConfig created by Packer",
+						Type: "ONE_TO_ONE_NAT",
+					},
+				},
+				Network: network.SelfLink,
+			},
+		},
+		ServiceAccounts: []*compute.ServiceAccount{
+			&compute.ServiceAccount{
+				Email: "default",
+				Scopes: []string{
+					"https://www.googleapis.com/auth/userinfo.email",
+					"https://www.googleapis.com/auth/compute",
+					"https://www.googleapis.com/auth/devstorage.full_control",
+				},
+			},
+		},
+		Tags: &compute.Tags{
+			Items: c.Tags,
+		},
+	}
+
+	d.ui.Message("Requesting instance creation...")
+	op, err := d.service.Instances.Insert(d.projectId, zone.Name, &instance).Do()
+	if err != nil {
+		return nil, err
+	}
+
+	errCh := make(chan error, 1)
+	go waitForState(errCh, "DONE", d.refreshZoneOp(zone.Name, op))
+	return errCh, nil
+}
+
+func (d *driverGCE) WaitForInstance(state, zone, name string) <-chan error {
+	errCh := make(chan error, 1)
+	go waitForState(errCh, state, d.refreshInstanceState(zone, name))
+	return errCh
+}
+
+func (d *driverGCE) getImage(name string) (image *compute.Image, err error) {
+	projects := []string{d.projectId, "debian-cloud", "centos-cloud"}
+	for _, project := range projects {
+		image, err = d.service.Images.Get(project, name).Do()
+		if err == nil && image != nil && image.SelfLink != "" {
+			return
+		}
+		image = nil
+	}
+
+	if err == nil {
+		err = fmt.Errorf("Image could not be found: %s", name)
+	}
+
+	return
+}
+
+func (d *driverGCE) refreshInstanceState(zone, name string) stateRefreshFunc {
+	return func() (string, error) {
+		instance, err := d.service.Instances.Get(d.projectId, zone, name).Do()
+		if err != nil {
+			return "", err
+		}
+		return instance.Status, nil
+	}
+}
+
+func (d *driverGCE) refreshGlobalOp(op *compute.Operation) stateRefreshFunc {
+	return func() (string, error) {
+		newOp, err := d.service.GlobalOperations.Get(d.projectId, op.Name).Do()
+		if err != nil {
+			return "", err
+		}
+
+		// If the op is done, check for errors
+		err = nil
+		if newOp.Status == "DONE" {
+			if newOp.Error != nil {
+				for _, e := range newOp.Error.Errors {
+					err = packer.MultiErrorAppend(err, fmt.Errorf(e.Message))
+				}
+			}
+		}
+
+		return newOp.Status, err
+	}
+}
+
+func (d *driverGCE) refreshZoneOp(zone string, op *compute.Operation) stateRefreshFunc {
+	return func() (string, error) {
+		newOp, err := d.service.ZoneOperations.Get(d.projectId, zone, op.Name).Do()
+		if err != nil {
+			return "", err
+		}
+
+		// If the op is done, check for errors
+		err = nil
+		if newOp.Status == "DONE" {
+			if newOp.Error != nil {
+				for _, e := range newOp.Error.Errors {
+					err = packer.MultiErrorAppend(err, fmt.Errorf(e.Message))
+				}
+			}
+		}
+
+		return newOp.Status, err
+	}
+}
+
+// stateRefreshFunc is used to refresh the state of a thing and is
+// used in conjunction with waitForState.
+type stateRefreshFunc func() (string, error)
+
+// waitForState will spin in a loop forever waiting for state to
+// reach a certain target.
+func waitForState(errCh chan<- error, target string, refresh stateRefreshFunc) {
+	for {
+		state, err := refresh()
+		if err != nil {
+			errCh <- err
+			return
+		}
+		if state == target {
+			errCh <- nil
+			return
+		}
+
+		time.Sleep(2 * time.Second)
+	}
+}

builder/googlecompute/driver_mock.go

@@ -0,0 +1,108 @@
+package googlecompute
+
+// DriverMock is a Driver implementation that is a mocked out so that
+// it can be used for tests.
+type DriverMock struct {
+	CreateImageName  string
+	CreateImageDesc  string
+	CreateImageURL   string
+	CreateImageErrCh <-chan error
+
+	DeleteImageName  string
+	DeleteImageErrCh <-chan error
+
+	DeleteInstanceZone  string
+	DeleteInstanceName  string
+	DeleteInstanceErrCh <-chan error
+	DeleteInstanceErr   error
+
+	GetNatIPZone   string
+	GetNatIPName   string
+	GetNatIPResult string
+	GetNatIPErr    error
+
+	RunInstanceConfig *InstanceConfig
+	RunInstanceErrCh  <-chan error
+	RunInstanceErr    error
+
+	WaitForInstanceState string
+	WaitForInstanceZone  string
+	WaitForInstanceName  string
+	WaitForInstanceErrCh <-chan error
+}
+
+func (d *DriverMock) CreateImage(name, description, url string) <-chan error {
+	d.CreateImageName = name
+	d.CreateImageDesc = description
+	d.CreateImageURL = url
+
+	resultCh := d.CreateImageErrCh
+	if resultCh == nil {
+		ch := make(chan error)
+		close(ch)
+		resultCh = ch
+	}
+
+	return resultCh
+}
+
+func (d *DriverMock) DeleteImage(name string) <-chan error {
+	d.DeleteImageName = name
+
+	resultCh := d.DeleteImageErrCh
+	if resultCh == nil {
+		ch := make(chan error)
+		close(ch)
+		resultCh = ch
+	}
+
+	return resultCh
+}
+
+func (d *DriverMock) DeleteInstance(zone, name string) (<-chan error, error) {
+	d.DeleteInstanceZone = zone
+	d.DeleteInstanceName = name
+
+	resultCh := d.DeleteInstanceErrCh
+	if resultCh == nil {
+		ch := make(chan error)
+		close(ch)
+		resultCh = ch
+	}
+
+	return resultCh, d.DeleteInstanceErr
+}
+
+func (d *DriverMock) GetNatIP(zone, name string) (string, error) {
+	d.GetNatIPZone = zone
+	d.GetNatIPName = name
+	return d.GetNatIPResult, d.GetNatIPErr
+}
+
+func (d *DriverMock) RunInstance(c *InstanceConfig) (<-chan error, error) {
+	d.RunInstanceConfig = c
+
+	resultCh := d.RunInstanceErrCh
+	if resultCh == nil {
+		ch := make(chan error)
+		close(ch)
+		resultCh = ch
+	}
+
+	return resultCh, d.RunInstanceErr
+}
+
+func (d *DriverMock) WaitForInstance(state, zone, name string) <-chan error {
+	d.WaitForInstanceState = state
+	d.WaitForInstanceZone = zone
+	d.WaitForInstanceName = name
+
+	resultCh := d.WaitForInstanceErrCh
+	if resultCh == nil {
+		ch := make(chan error)
+		close(ch)
+		resultCh = ch
+	}
+
+	return resultCh
+}

builder/googlecompute/private_key.go

@@ -0,0 +1,43 @@
+package googlecompute
+
+import (
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"io/ioutil"
+)
+
+// processPrivateKeyFile takes a private key file and an optional passphrase
+// and decodes it to a byte slice.
+func processPrivateKeyFile(privateKeyFile, passphrase string) ([]byte, error) {
+	rawPrivateKeyBytes, err := ioutil.ReadFile(privateKeyFile)
+	if err != nil {
+		return nil, fmt.Errorf("Failed loading private key file: %s", err)
+	}
+
+	PEMBlock, _ := pem.Decode(rawPrivateKeyBytes)
+	if PEMBlock == nil {
+		return nil, fmt.Errorf(
+			"%s does not contain a vaild private key", privateKeyFile)
+	}
+
+	if x509.IsEncryptedPEMBlock(PEMBlock) {
+		if passphrase == "" {
+			return nil, errors.New("a passphrase must be specified when using an encrypted private key")
+		}
+
+		decryptedPrivateKeyBytes, err := x509.DecryptPEMBlock(PEMBlock, []byte(passphrase))
+		if err != nil {
+			return nil, fmt.Errorf("Failed decrypting private key: %s", err)
+		}
+
+		b := &pem.Block{
+			Type:  "RSA PRIVATE KEY",
+			Bytes: decryptedPrivateKeyBytes,
+		}
+		return pem.EncodeToMemory(b), nil
+	}
+
+	return rawPrivateKeyBytes, nil
+}

builder/googlecompute/private_key_test.go

@@ -0,0 +1,78 @@
+package googlecompute
+
+import (
+	"crypto/rand"
+	"crypto/x509"
+	"encoding/pem"
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+func testPrivateKeyFile(t *testing.T) string {
+	tf, err := ioutil.TempFile("", "packer")
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+	defer tf.Close()
+
+	b := &pem.Block{
+		Type:  "RSA PRIVATE KEY",
+		Bytes: []byte("what"),
+	}
+
+	if err := pem.Encode(tf, b); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	return tf.Name()
+}
+
+func TestProcesssPrivateKeyFile(t *testing.T) {
+	path := testPrivateKeyFile(t)
+	defer os.Remove(path)
+
+	data, err := processPrivateKeyFile(path, "")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if len(data) <= 0 {
+		t.Fatalf("bad: %#v", data)
+	}
+}
+
+func TestProcessPrivateKeyFile_encrypted(t *testing.T) {
+	// Encrypt the file
+	b, err := x509.EncryptPEMBlock(rand.Reader,
+		"RSA PRIVATE KEY",
+		[]byte("what"),
+		[]byte("password"),
+		x509.PEMCipherAES128)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	tf, err := ioutil.TempFile("", "packer")
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+	defer os.Remove(tf.Name())
+
+	err = pem.Encode(tf, b)
+	tf.Close()
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	path := tf.Name()
+
+	// Should have an error with a bad password
+	if _, err := processPrivateKeyFile(path, "bad"); err == nil {
+		t.Fatal("should error")
+	}
+
+	if _, err := processPrivateKeyFile(path, "password"); err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+}

builder/googlecompute/ssh.go

@@ -0,0 +1,34 @@
+package googlecompute
+
+import (
+	"fmt"
+
+	gossh "code.google.com/p/go.crypto/ssh"
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/communicator/ssh"
+)
+
+// sshAddress returns the ssh address.
+func sshAddress(state multistep.StateBag) (string, error) {
+	config := state.Get("config").(*Config)
+	ipAddress := state.Get("instance_ip").(string)
+	return fmt.Sprintf("%s:%d", ipAddress, config.SSHPort), nil
+}
+
+// sshConfig returns the ssh configuration.
+func sshConfig(state multistep.StateBag) (*gossh.ClientConfig, error) {
+	config := state.Get("config").(*Config)
+	privateKey := state.Get("ssh_private_key").(string)
+
+	keyring := new(ssh.SimpleKeychain)
+	if err := keyring.AddPEMKey(privateKey); err != nil {
+		return nil, fmt.Errorf("Error setting up SSH config: %s", err)
+	}
+
+	sshConfig := &gossh.ClientConfig{
+		User: config.SSHUsername,
+		Auth: []gossh.ClientAuth{gossh.ClientAuthKeyring(keyring)},
+	}
+
+	return sshConfig, nil
+}

builder/googlecompute/step_create_image.go

@@ -0,0 +1,52 @@
+package googlecompute
+
+import (
+	"fmt"
+	"path/filepath"
+
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+)
+
+// StepCreateImage represents a Packer build step that creates GCE machine
+// images.
+type StepCreateImage int
+
+// Run executes the Packer build step that creates a GCE machine image.
+//
+// Currently the only way to create a GCE image is to run the gcimagebundle
+// command on the running GCE instance.
+func (s *StepCreateImage) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*Config)
+	comm := state.Get("communicator").(packer.Communicator)
+	ui := state.Get("ui").(packer.Ui)
+
+	sudoPrefix := ""
+	if config.SSHUsername != "root" {
+		sudoPrefix = "sudo "
+	}
+
+	imageFilename := fmt.Sprintf("%s.tar.gz", config.ImageName)
+	imageBundleCmd := "/usr/bin/gcimagebundle -d /dev/sda -o /tmp/"
+
+	ui.Say("Creating image...")
+	cmd := new(packer.RemoteCmd)
+	cmd.Command = fmt.Sprintf("%s%s --output_file_name %s",
+		sudoPrefix, imageBundleCmd, imageFilename)
+	err := cmd.StartWithUi(comm, ui)
+	if err == nil && cmd.ExitStatus != 0 {
+		err = fmt.Errorf(
+			"gcimagebundle exited with non-zero exit status: %d", cmd.ExitStatus)
+	}
+	if err != nil {
+		err := fmt.Errorf("Error creating image: %s", err)
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	state.Put("image_file_name", filepath.Join("/tmp", imageFilename))
+	return multistep.ActionContinue
+}
+
+func (s *StepCreateImage) Cleanup(state multistep.StateBag) {}

builder/googlecompute/step_create_image_test.go

@@ -0,0 +1,96 @@
+package googlecompute
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+)
+
+func TestStepCreateImage_impl(t *testing.T) {
+	var _ multistep.Step = new(StepCreateImage)
+}
+
+func TestStepCreateImage(t *testing.T) {
+	state := testState(t)
+	step := new(StepCreateImage)
+	defer step.Cleanup(state)
+
+	comm := new(packer.MockCommunicator)
+	state.Put("communicator", comm)
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionContinue {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify
+	if !comm.StartCalled {
+		t.Fatal("start should be called")
+	}
+	if strings.HasPrefix(comm.StartCmd.Command, "sudo") {
+		t.Fatal("should not sudo")
+	}
+	if !strings.Contains(comm.StartCmd.Command, "gcimagebundle") {
+		t.Fatalf("bad command: %#v", comm.StartCmd.Command)
+	}
+
+	if _, ok := state.GetOk("image_file_name"); !ok {
+		t.Fatal("should have image")
+	}
+}
+
+func TestStepCreateImage_badExitStatus(t *testing.T) {
+	state := testState(t)
+	step := new(StepCreateImage)
+	defer step.Cleanup(state)
+
+	comm := new(packer.MockCommunicator)
+	comm.StartExitStatus = 12
+	state.Put("communicator", comm)
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionHalt {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	if _, ok := state.GetOk("error"); !ok {
+		t.Fatal("should have error")
+	}
+	if _, ok := state.GetOk("image_file_name"); ok {
+		t.Fatal("should NOT have image")
+	}
+}
+
+func TestStepCreateImage_nonRoot(t *testing.T) {
+	state := testState(t)
+	step := new(StepCreateImage)
+	defer step.Cleanup(state)
+
+	comm := new(packer.MockCommunicator)
+	state.Put("communicator", comm)
+
+	config := state.Get("config").(*Config)
+	config.SSHUsername = "bob"
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionContinue {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify
+	if !comm.StartCalled {
+		t.Fatal("start should be called")
+	}
+	if !strings.HasPrefix(comm.StartCmd.Command, "sudo") {
+		t.Fatal("should sudo")
+	}
+	if !strings.Contains(comm.StartCmd.Command, "gcimagebundle") {
+		t.Fatalf("bad command: %#v", comm.StartCmd.Command)
+	}
+
+	if _, ok := state.GetOk("image_file_name"); !ok {
+		t.Fatal("should have image")
+	}
+}

builder/googlecompute/step_create_instance.go

@@ -0,0 +1,95 @@
+package googlecompute
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/common/uuid"
+	"github.com/mitchellh/packer/packer"
+)
+
+// StepCreateInstance represents a Packer build step that creates GCE instances.
+type StepCreateInstance struct {
+	instanceName string
+}
+
+// Run executes the Packer build step that creates a GCE instance.
+func (s *StepCreateInstance) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*Config)
+	driver := state.Get("driver").(Driver)
+	sshPublicKey := state.Get("ssh_public_key").(string)
+	ui := state.Get("ui").(packer.Ui)
+
+	ui.Say("Creating instance...")
+	name := fmt.Sprintf("packer-%s", uuid.TimeOrderedUUID())
+
+	errCh, err := driver.RunInstance(&InstanceConfig{
+		Description: "New instance created by Packer",
+		Image:       config.SourceImage,
+		MachineType: config.MachineType,
+		Metadata: map[string]string{
+			"sshKeys": fmt.Sprintf("%s:%s", config.SSHUsername, sshPublicKey),
+		},
+		Name:    name,
+		Network: config.Network,
+		Tags:    config.Tags,
+		Zone:    config.Zone,
+	})
+
+	if err == nil {
+		ui.Message("Waiting for creation operation to complete...")
+		select {
+		case err = <-errCh:
+		case <-time.After(config.stateTimeout):
+			err = errors.New("time out while waiting for instance to create")
+		}
+	}
+
+	if err != nil {
+		err := fmt.Errorf("Error creating instance: %s", err)
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	ui.Message("Instance has been created!")
+
+	// Things succeeded, store the name so we can remove it later
+	state.Put("instance_name", name)
+	s.instanceName = name
+
+	return multistep.ActionContinue
+}
+
+// Cleanup destroys the GCE instance created during the image creation process.
+func (s *StepCreateInstance) Cleanup(state multistep.StateBag) {
+	if s.instanceName == "" {
+		return
+	}
+
+	config := state.Get("config").(*Config)
+	driver := state.Get("driver").(Driver)
+	ui := state.Get("ui").(packer.Ui)
+
+	ui.Say("Deleting instance...")
+	errCh, err := driver.DeleteInstance(config.Zone, s.instanceName)
+	if err == nil {
+		select {
+		case err = <-errCh:
+		case <-time.After(config.stateTimeout):
+			err = errors.New("time out while waiting for instance to delete")
+		}
+	}
+
+	if err != nil {
+		ui.Error(fmt.Sprintf(
+			"Error deleting instance. Please delete it manually.\n\n"+
+				"Name: %s\n"+
+				"Error: %s", s.instanceName, err))
+	}
+
+	s.instanceName = ""
+	return
+}

builder/googlecompute/step_create_instance_test.go

@@ -0,0 +1,128 @@
+package googlecompute
+
+import (
+	"errors"
+	"github.com/mitchellh/multistep"
+	"testing"
+	"time"
+)
+
+func TestStepCreateInstance_impl(t *testing.T) {
+	var _ multistep.Step = new(StepCreateInstance)
+}
+
+func TestStepCreateInstance(t *testing.T) {
+	state := testState(t)
+	step := new(StepCreateInstance)
+	defer step.Cleanup(state)
+
+	state.Put("ssh_public_key", "key")
+
+	config := state.Get("config").(*Config)
+	driver := state.Get("driver").(*DriverMock)
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionContinue {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify state
+	nameRaw, ok := state.GetOk("instance_name")
+	if !ok {
+		t.Fatal("should have instance name")
+	}
+
+	// cleanup
+	step.Cleanup(state)
+
+	if driver.DeleteInstanceName != nameRaw.(string) {
+		t.Fatal("should've deleted instance")
+	}
+	if driver.DeleteInstanceZone != config.Zone {
+		t.Fatal("bad zone: %#v", driver.DeleteInstanceZone)
+	}
+}
+
+func TestStepCreateInstance_error(t *testing.T) {
+	state := testState(t)
+	step := new(StepCreateInstance)
+	defer step.Cleanup(state)
+
+	state.Put("ssh_public_key", "key")
+
+	driver := state.Get("driver").(*DriverMock)
+	driver.RunInstanceErr = errors.New("error")
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionHalt {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify state
+	if _, ok := state.GetOk("error"); !ok {
+		t.Fatal("should have error")
+	}
+	if _, ok := state.GetOk("instance_name"); ok {
+		t.Fatal("should NOT have instance name")
+	}
+}
+
+func TestStepCreateInstance_errorOnChannel(t *testing.T) {
+	state := testState(t)
+	step := new(StepCreateInstance)
+	defer step.Cleanup(state)
+
+	errCh := make(chan error, 1)
+	errCh <- errors.New("error")
+
+	state.Put("ssh_public_key", "key")
+
+	driver := state.Get("driver").(*DriverMock)
+	driver.RunInstanceErrCh = errCh
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionHalt {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify state
+	if _, ok := state.GetOk("error"); !ok {
+		t.Fatal("should have error")
+	}
+	if _, ok := state.GetOk("instance_name"); ok {
+		t.Fatal("should NOT have instance name")
+	}
+}
+
+func TestStepCreateInstance_errorTimeout(t *testing.T) {
+	state := testState(t)
+	step := new(StepCreateInstance)
+	defer step.Cleanup(state)
+
+	errCh := make(chan error, 1)
+	go func() {
+		<-time.After(10 * time.Millisecond)
+		errCh <- nil
+	}()
+
+	state.Put("ssh_public_key", "key")
+
+	config := state.Get("config").(*Config)
+	config.stateTimeout = 1 * time.Microsecond
+
+	driver := state.Get("driver").(*DriverMock)
+	driver.RunInstanceErrCh = errCh
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionHalt {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify state
+	if _, ok := state.GetOk("error"); !ok {
+		t.Fatal("should have error")
+	}
+	if _, ok := state.GetOk("instance_name"); ok {
+		t.Fatal("should NOT have instance name")
+	}
+}

builder/googlecompute/step_create_ssh_key.go

@@ -0,0 +1,51 @@
+package googlecompute
+
+import (
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/pem"
+	"fmt"
+
+	"code.google.com/p/go.crypto/ssh"
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+)
+
+// StepCreateSSHKey represents a Packer build step that generates SSH key pairs.
+type StepCreateSSHKey int
+
+// Run executes the Packer build step that generates SSH key pairs.
+func (s *StepCreateSSHKey) Run(state multistep.StateBag) multistep.StepAction {
+	ui := state.Get("ui").(packer.Ui)
+
+	ui.Say("Creating temporary SSH key for instance...")
+	priv, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		err := fmt.Errorf("Error creating temporary ssh key: %s", err)
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	priv_blk := pem.Block{
+		Type:    "RSA PRIVATE KEY",
+		Headers: nil,
+		Bytes:   x509.MarshalPKCS1PrivateKey(priv),
+	}
+
+	pub, err := ssh.NewPublicKey(&priv.PublicKey)
+	if err != nil {
+		err := fmt.Errorf("Error creating temporary ssh key: %s", err)
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	state.Put("ssh_private_key", string(pem.EncodeToMemory(&priv_blk)))
+	state.Put("ssh_public_key", string(ssh.MarshalAuthorizedKey(pub)))
+	return multistep.ActionContinue
+}
+
+// Nothing to clean up. SSH keys are associated with a single GCE instance.
+func (s *StepCreateSSHKey) Cleanup(state multistep.StateBag) {}

builder/googlecompute/step_create_ssh_key_test.go

@@ -0,0 +1,29 @@
+package googlecompute
+
+import (
+	"github.com/mitchellh/multistep"
+	"testing"
+)
+
+func TestStepCreateSSHKey_impl(t *testing.T) {
+	var _ multistep.Step = new(StepCreateSSHKey)
+}
+
+func TestStepCreateSSHKey(t *testing.T) {
+	state := testState(t)
+	step := new(StepCreateSSHKey)
+	defer step.Cleanup(state)
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionContinue {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify that we have a public/private key
+	if _, ok := state.GetOk("ssh_private_key"); !ok {
+		t.Fatal("should have key")
+	}
+	if _, ok := state.GetOk("ssh_public_key"); !ok {
+		t.Fatal("should have key")
+	}
+}

builder/googlecompute/step_instance_info.go

@@ -0,0 +1,53 @@
+package googlecompute
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+)
+
+// stepInstanceInfo represents a Packer build step that gathers GCE instance info.
+type StepInstanceInfo int
+
+// Run executes the Packer build step that gathers GCE instance info.
+func (s *StepInstanceInfo) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*Config)
+	driver := state.Get("driver").(Driver)
+	ui := state.Get("ui").(packer.Ui)
+
+	instanceName := state.Get("instance_name").(string)
+
+	ui.Say("Waiting for the instance to become running...")
+	errCh := driver.WaitForInstance("RUNNING", config.Zone, instanceName)
+	var err error
+	select {
+	case err = <-errCh:
+	case <-time.After(config.stateTimeout):
+		err = errors.New("time out while waiting for instance to become running")
+	}
+
+	if err != nil {
+		err := fmt.Errorf("Error waiting for instance: %s", err)
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	ip, err := driver.GetNatIP(config.Zone, instanceName)
+	if err != nil {
+		err := fmt.Errorf("Error retrieving instance nat ip address: %s", err)
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	ui.Message(fmt.Sprintf("IP: %s", ip))
+	state.Put("instance_ip", ip)
+	return multistep.ActionContinue
+}
+
+// Cleanup.
+func (s *StepInstanceInfo) Cleanup(state multistep.StateBag) {}

builder/googlecompute/step_instance_info_test.go

@@ -0,0 +1,134 @@
+package googlecompute
+
+import (
+	"errors"
+	"github.com/mitchellh/multistep"
+	"testing"
+	"time"
+)
+
+func TestStepInstanceInfo_impl(t *testing.T) {
+	var _ multistep.Step = new(StepInstanceInfo)
+}
+
+func TestStepInstanceInfo(t *testing.T) {
+	state := testState(t)
+	step := new(StepInstanceInfo)
+	defer step.Cleanup(state)
+
+	state.Put("instance_name", "foo")
+
+	config := state.Get("config").(*Config)
+	driver := state.Get("driver").(*DriverMock)
+	driver.GetNatIPResult = "1.2.3.4"
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionContinue {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify state
+	if driver.WaitForInstanceState != "RUNNING" {
+		t.Fatalf("bad: %#v", driver.WaitForInstanceState)
+	}
+	if driver.WaitForInstanceZone != config.Zone {
+		t.Fatalf("bad: %#v", driver.WaitForInstanceZone)
+	}
+	if driver.WaitForInstanceName != "foo" {
+		t.Fatalf("bad: %#v", driver.WaitForInstanceName)
+	}
+
+	ipRaw, ok := state.GetOk("instance_ip")
+	if !ok {
+		t.Fatal("should have ip")
+	}
+	if ip, ok := ipRaw.(string); !ok {
+		t.Fatal("ip is not a string")
+	} else if ip != "1.2.3.4" {
+		t.Fatalf("bad ip: %s", ip)
+	}
+}
+
+func TestStepInstanceInfo_getNatIPError(t *testing.T) {
+	state := testState(t)
+	step := new(StepInstanceInfo)
+	defer step.Cleanup(state)
+
+	state.Put("instance_name", "foo")
+
+	driver := state.Get("driver").(*DriverMock)
+	driver.GetNatIPErr = errors.New("error")
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionHalt {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify state
+	if _, ok := state.GetOk("error"); !ok {
+		t.Fatal("should have error")
+	}
+	if _, ok := state.GetOk("instance_ip"); ok {
+		t.Fatal("should NOT have instance IP")
+	}
+}
+
+func TestStepInstanceInfo_waitError(t *testing.T) {
+	state := testState(t)
+	step := new(StepInstanceInfo)
+	defer step.Cleanup(state)
+
+	state.Put("instance_name", "foo")
+
+	errCh := make(chan error, 1)
+	errCh <- errors.New("error")
+
+	driver := state.Get("driver").(*DriverMock)
+	driver.WaitForInstanceErrCh = errCh
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionHalt {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify state
+	if _, ok := state.GetOk("error"); !ok {
+		t.Fatal("should have error")
+	}
+	if _, ok := state.GetOk("instance_ip"); ok {
+		t.Fatal("should NOT have instance IP")
+	}
+}
+
+func TestStepInstanceInfo_errorTimeout(t *testing.T) {
+	state := testState(t)
+	step := new(StepInstanceInfo)
+	defer step.Cleanup(state)
+
+	errCh := make(chan error, 1)
+	go func() {
+		<-time.After(10 * time.Millisecond)
+		errCh <- nil
+	}()
+
+	state.Put("instance_name", "foo")
+
+	config := state.Get("config").(*Config)
+	config.stateTimeout = 1 * time.Microsecond
+
+	driver := state.Get("driver").(*DriverMock)
+	driver.WaitForInstanceErrCh = errCh
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionHalt {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify state
+	if _, ok := state.GetOk("error"); !ok {
+		t.Fatal("should have error")
+	}
+	if _, ok := state.GetOk("instance_ip"); ok {
+		t.Fatal("should NOT have instance IP")
+	}
+}

builder/googlecompute/step_register_image.go

@@ -0,0 +1,46 @@
+package googlecompute
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+)
+
+// StepRegisterImage represents a Packer build step that registers GCE machine images.
+type StepRegisterImage int
+
+// Run executes the Packer build step that registers a GCE machine image.
+func (s *StepRegisterImage) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*Config)
+	driver := state.Get("driver").(Driver)
+	ui := state.Get("ui").(packer.Ui)
+
+	var err error
+	imageURL := fmt.Sprintf(
+		"https://storage.cloud.google.com/%s/%s.tar.gz",
+		config.BucketName, config.ImageName)
+
+	ui.Say("Registering image...")
+	errCh := driver.CreateImage(config.ImageName, config.ImageDescription, imageURL)
+	select {
+	case err = <-errCh:
+	case <-time.After(config.stateTimeout):
+		err = errors.New("time out while waiting for image to register")
+	}
+
+	if err != nil {
+		err := fmt.Errorf("Error waiting for image: %s", err)
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	state.Put("image_name", config.ImageName)
+	return multistep.ActionContinue
+}
+
+// Cleanup.
+func (s *StepRegisterImage) Cleanup(state multistep.StateBag) {}

builder/googlecompute/step_register_image_test.go

@@ -0,0 +1,100 @@
+package googlecompute
+
+import (
+	"errors"
+	"github.com/mitchellh/multistep"
+	"testing"
+	"time"
+)
+
+func TestStepRegisterImage_impl(t *testing.T) {
+	var _ multistep.Step = new(StepRegisterImage)
+}
+
+func TestStepRegisterImage(t *testing.T) {
+	state := testState(t)
+	step := new(StepRegisterImage)
+	defer step.Cleanup(state)
+
+	config := state.Get("config").(*Config)
+	driver := state.Get("driver").(*DriverMock)
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionContinue {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify state
+	if driver.CreateImageName != config.ImageName {
+		t.Fatalf("bad: %#v", driver.CreateImageName)
+	}
+	if driver.CreateImageDesc != config.ImageDescription {
+		t.Fatalf("bad: %#v", driver.CreateImageDesc)
+	}
+
+	nameRaw, ok := state.GetOk("image_name")
+	if !ok {
+		t.Fatal("should have name")
+	}
+	if name, ok := nameRaw.(string); !ok {
+		t.Fatal("name is not a string")
+	} else if name != config.ImageName {
+		t.Fatalf("bad name: %s", name)
+	}
+}
+
+func TestStepRegisterImage_waitError(t *testing.T) {
+	state := testState(t)
+	step := new(StepRegisterImage)
+	defer step.Cleanup(state)
+
+	errCh := make(chan error, 1)
+	errCh <- errors.New("error")
+
+	driver := state.Get("driver").(*DriverMock)
+	driver.CreateImageErrCh = errCh
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionHalt {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify state
+	if _, ok := state.GetOk("error"); !ok {
+		t.Fatal("should have error")
+	}
+	if _, ok := state.GetOk("image_name"); ok {
+		t.Fatal("should NOT have image_name")
+	}
+}
+
+func TestStepRegisterImage_errorTimeout(t *testing.T) {
+	state := testState(t)
+	step := new(StepRegisterImage)
+	defer step.Cleanup(state)
+
+	errCh := make(chan error, 1)
+	go func() {
+		<-time.After(10 * time.Millisecond)
+		errCh <- nil
+	}()
+
+	config := state.Get("config").(*Config)
+	config.stateTimeout = 1 * time.Microsecond
+
+	driver := state.Get("driver").(*DriverMock)
+	driver.CreateImageErrCh = errCh
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionHalt {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify state
+	if _, ok := state.GetOk("error"); !ok {
+		t.Fatal("should have error")
+	}
+	if _, ok := state.GetOk("image_name"); ok {
+		t.Fatal("should NOT have image name")
+	}
+}

builder/googlecompute/step_test.go

@@ -0,0 +1,20 @@
+package googlecompute
+
+import (
+	"bytes"
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+	"testing"
+)
+
+func testState(t *testing.T) multistep.StateBag {
+	state := new(multistep.BasicStateBag)
+	state.Put("config", testConfigStruct(t))
+	state.Put("driver", &DriverMock{})
+	state.Put("hook", &packer.MockHook{})
+	state.Put("ui", &packer.BasicUi{
+		Reader: new(bytes.Buffer),
+		Writer: new(bytes.Buffer),
+	})
+	return state
+}

builder/googlecompute/step_update_gsutil.go

@@ -0,0 +1,52 @@
+package googlecompute
+
+import (
+	"fmt"
+
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+)
+
+// StepUpdateGsutil represents a Packer build step that updates the gsutil
+// utility to the latest version available.
+type StepUpdateGsutil int
+
+// Run executes the Packer build step that updates the gsutil utility to the
+// latest version available.
+//
+// This step is required to prevent the image creation process from hanging;
+// the image creation process utilizes the gcimagebundle cli tool which will
+// prompt to update gsutil if a newer version is available.
+func (s *StepUpdateGsutil) Run(state multistep.StateBag) multistep.StepAction {
+	comm := state.Get("communicator").(packer.Communicator)
+	config := state.Get("config").(*Config)
+	ui := state.Get("ui").(packer.Ui)
+
+	sudoPrefix := ""
+
+	if config.SSHUsername != "root" {
+		sudoPrefix = "sudo "
+	}
+
+	gsutilUpdateCmd := "/usr/local/bin/gsutil update -n -f"
+	cmd := new(packer.RemoteCmd)
+	cmd.Command = fmt.Sprintf("%s%s", sudoPrefix, gsutilUpdateCmd)
+
+	ui.Say("Updating gsutil...")
+	err := cmd.StartWithUi(comm, ui)
+	if err == nil && cmd.ExitStatus != 0 {
+		err = fmt.Errorf(
+			"gsutil update exited with non-zero exit status: %d", cmd.ExitStatus)
+	}
+	if err != nil {
+		err := fmt.Errorf("Error updating gsutil: %s", err)
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	return multistep.ActionContinue
+}
+
+// Cleanup.
+func (s *StepUpdateGsutil) Cleanup(state multistep.StateBag) {}

builder/googlecompute/step_update_gsutil_test.go

@@ -0,0 +1,85 @@
+package googlecompute
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+)
+
+func TestStepUpdateGsutil_impl(t *testing.T) {
+	var _ multistep.Step = new(StepUpdateGsutil)
+}
+
+func TestStepUpdateGsutil(t *testing.T) {
+	state := testState(t)
+	step := new(StepUpdateGsutil)
+	defer step.Cleanup(state)
+
+	comm := new(packer.MockCommunicator)
+	state.Put("communicator", comm)
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionContinue {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify
+	if !comm.StartCalled {
+		t.Fatal("start should be called")
+	}
+	if strings.HasPrefix(comm.StartCmd.Command, "sudo") {
+		t.Fatal("should not sudo")
+	}
+	if !strings.Contains(comm.StartCmd.Command, "gsutil update") {
+		t.Fatalf("bad command: %#v", comm.StartCmd.Command)
+	}
+}
+
+func TestStepUpdateGsutil_badExitStatus(t *testing.T) {
+	state := testState(t)
+	step := new(StepUpdateGsutil)
+	defer step.Cleanup(state)
+
+	comm := new(packer.MockCommunicator)
+	comm.StartExitStatus = 12
+	state.Put("communicator", comm)
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionHalt {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	if _, ok := state.GetOk("error"); !ok {
+		t.Fatal("should have error")
+	}
+}
+
+func TestStepUpdateGsutil_nonRoot(t *testing.T) {
+	state := testState(t)
+	step := new(StepUpdateGsutil)
+	defer step.Cleanup(state)
+
+	comm := new(packer.MockCommunicator)
+	state.Put("communicator", comm)
+
+	config := state.Get("config").(*Config)
+	config.SSHUsername = "bob"
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionContinue {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify
+	if !comm.StartCalled {
+		t.Fatal("start should be called")
+	}
+	if !strings.HasPrefix(comm.StartCmd.Command, "sudo") {
+		t.Fatal("should sudo")
+	}
+	if !strings.Contains(comm.StartCmd.Command, "gsutil update") {
+		t.Fatalf("bad command: %#v", comm.StartCmd.Command)
+	}
+}

builder/googlecompute/step_upload_image.go

@@ -0,0 +1,45 @@
+package googlecompute
+
+import (
+	"fmt"
+
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+)
+
+// StepUploadImage represents a Packer build step that uploads GCE machine images.
+type StepUploadImage int
+
+// Run executes the Packer build step that uploads a GCE machine image.
+func (s *StepUploadImage) Run(state multistep.StateBag) multistep.StepAction {
+	comm := state.Get("communicator").(packer.Communicator)
+	config := state.Get("config").(*Config)
+	imageFilename := state.Get("image_file_name").(string)
+	ui := state.Get("ui").(packer.Ui)
+
+	sudoPrefix := ""
+	if config.SSHUsername != "root" {
+		sudoPrefix = "sudo "
+	}
+
+	ui.Say("Uploading image...")
+	cmd := new(packer.RemoteCmd)
+	cmd.Command = fmt.Sprintf("%s/usr/local/bin/gsutil cp %s gs://%s",
+		sudoPrefix, imageFilename, config.BucketName)
+	err := cmd.StartWithUi(comm, ui)
+	if err == nil && cmd.ExitStatus != 0 {
+		err = fmt.Errorf(
+			"gsutil exited with non-zero exit status: %d", cmd.ExitStatus)
+	}
+	if err != nil {
+		err := fmt.Errorf("Error uploading image: %s", err)
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	return multistep.ActionContinue
+}
+
+// Cleanup.
+func (s *StepUploadImage) Cleanup(state multistep.StateBag) {}

builder/googlecompute/step_upload_image_test.go

@@ -0,0 +1,88 @@
+package googlecompute
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+)
+
+func TestStepUploadImage_impl(t *testing.T) {
+	var _ multistep.Step = new(StepUploadImage)
+}
+
+func TestStepUploadImage(t *testing.T) {
+	state := testState(t)
+	step := new(StepUploadImage)
+	defer step.Cleanup(state)
+
+	comm := new(packer.MockCommunicator)
+	state.Put("communicator", comm)
+	state.Put("image_file_name", "foo")
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionContinue {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify
+	if !comm.StartCalled {
+		t.Fatal("start should be called")
+	}
+	if strings.HasPrefix(comm.StartCmd.Command, "sudo") {
+		t.Fatal("should not sudo")
+	}
+	if !strings.Contains(comm.StartCmd.Command, "gsutil cp") {
+		t.Fatalf("bad command: %#v", comm.StartCmd.Command)
+	}
+}
+
+func TestStepUploadImage_badExitStatus(t *testing.T) {
+	state := testState(t)
+	step := new(StepUploadImage)
+	defer step.Cleanup(state)
+
+	comm := new(packer.MockCommunicator)
+	comm.StartExitStatus = 12
+	state.Put("communicator", comm)
+	state.Put("image_file_name", "foo")
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionHalt {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	if _, ok := state.GetOk("error"); !ok {
+		t.Fatal("should have error")
+	}
+}
+
+func TestStepUploadImage_nonRoot(t *testing.T) {
+	state := testState(t)
+	step := new(StepUploadImage)
+	defer step.Cleanup(state)
+
+	comm := new(packer.MockCommunicator)
+	state.Put("communicator", comm)
+	state.Put("image_file_name", "foo")
+
+	config := state.Get("config").(*Config)
+	config.SSHUsername = "bob"
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionContinue {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// Verify
+	if !comm.StartCalled {
+		t.Fatal("start should be called")
+	}
+	if !strings.HasPrefix(comm.StartCmd.Command, "sudo") {
+		t.Fatal("should sudo")
+	}
+	if !strings.Contains(comm.StartCmd.Command, "gsutil cp") {
+		t.Fatalf("bad command: %#v", comm.StartCmd.Command)
+	}
+}

config.go

@@ -24,6 +24,7 @@ const defaultConfig = `
 		"amazon-instance": "packer-builder-amazon-instance",
 		"digitalocean": "packer-builder-digitalocean",
 		"docker": "packer-builder-docker",
+		"googlecompute": "packer-builder-googlecompute",
 		"openstack": "packer-builder-openstack",
 		"qemu": "packer-builder-qemu",
 		"virtualbox": "packer-builder-virtualbox",

plugin/builder-googlecompute/main.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"github.com/mitchellh/packer/builder/googlecompute"
+	"github.com/mitchellh/packer/packer/plugin"
+)
+
+func main() {
+	server, err := plugin.Server()
+	if err != nil {
+		panic(err)
+	}
+	server.RegisterBuilder(new(googlecompute.Builder))
+	server.Serve()
+}

plugin/builder-googlecompute/main_test.go

@@ -0,0 +1 @@
+package main

website/source/docs/builders/googlecompute.markdown

@@ -0,0 +1,127 @@
+---
+layout: "docs"
+---
+
+# Google Compute Builder
+
+Type: `googlecompute`
+
+The `googlecompute` builder is able to create
+[images](https://developers.google.com/compute/docs/images)
+for use with [Google Compute Engine](https://cloud.google.com/products/compute-engine)
+(GCE) based on existing images. Google Compute Engine doesn't allow the creation
+of images from scratch.
+
+## Setting Up API Access
+
+There is a small setup step required in order to obtain the credentials
+that Packer needs to use Google Compute Engine. This needs to be done only
+once if you intend to share the credentials.
+
+In order for Packer to talk to Google Compute Engine, it will need
+a _client secrets_ JSON file and a _client private key_. Both of these are
+obtained from the [Google Cloud Console](https://cloud.google.com/console).
+
+Follow the steps below:
+
+1. Log into the [Google Cloud Console](https://cloud.google.com/console)
+2. Click on the project you want to use Packer with (or create one if you
+   don't have one yet).
+3. Click "APIs & auth" in the left sidebar
+4. Click "Registered apps" in the left sidebar
+5. Click "Register App" and register a "Web Application". Choose any
+   name you'd like.
+7. After creating the app, click "Certificate" (below the OAuth 2.0 Client
+   ID section), and click "Download JSON". This is your _client secrets JSON_
+   file. Make sure you didn't download the JSON from the "OAuth 2.0" section!
+   This is a common mistake and will cause the builder to not work.
+8. Next, click "Generate Certificate". You should be prompted to download
+   a private key. Note the password for the private key! This private key
+   is your _client private key_.
+
+Finally, one last step, you'll have to convert the `p12` file you
+got from Google into the PEM format. You can do this with OpenSSL, which
+is installed standard on most Unixes:
+
+```
+$ openssl pkcs12 -in <path to .p12> -nocerts -passin pass:notasecret \
+    -nodes -out private_key.pem
+```
+
+The client secrets JSON you downloaded along with the new "private\_key.pem"
+file are the two files you need to configure Packer with to talk to GCE.
+
+## Basic Example
+
+Below is a fully functioning example. It doesn't do anything useful,
+since no provisioners are defined, but it will effectively repackage an
+existing GCE image. The client secrets file and private key file are the
+files obtained in the previous section.
+
+<pre class="prettyprint">
+{
+  "type": "googlecompute",
+  "bucket_name": "packer-images",
+  "client_secrets_file": "client_secret.json",
+  "private_key_file": "XXXXXX-privatekey.p12",
+  "project_id": "my-project",
+  "source_image": "debian-7-wheezy-v20131014",
+  "zone": "us-central1-a"
+}
+</pre>
+
+## Configuration Reference
+
+Configuration options are organized below into two categories: required and optional. Within
+each category, the available options are alphabetized and described.
+
+Required:
+
+* `bucket_name` (string) - The Google Cloud Storage bucket to store the
+  images that are created.
+
+* `client_secrets_file` (string) - The client secrets JSON file that
+  was set up in the section above.
+
+* `private_key_file` (string) - The client private key file that was
+  generated in the section above.
+
+* `project_id` (string) - The project ID that will be used to launch instances
+  and store images.
+
+* `source_image` (string) - The source image to use to create the new image
+  from. Example: "debian-7"
+
+* `zone` (string) - The zone in which to launch the instance used to create
+  the image. Example: "us-central1-a"
+
+Optional:
+
+* `image_name` (string) - The unique name of the resulting image.
+  Defaults to `packer-{{timestamp}}`.
+
+* `image_description` (string) - The description of the resulting image.
+
+* `machine_type` (string) - The machine type. Defaults to `n1-standard-1`.
+
+* `network` (string) - The Google Compute network to use for the launched
+  instance. Defaults to `default`.
+
+* `passphrase` (string) - The passphrase to use if the `private_key_file`
+  is encrypted.
+
+* `ssh_port` (int) - The SSH port. Defaults to 22.
+
+* `ssh_timeout` (string) - The time to wait for SSH to become available.
+  Defaults to "1m".
+
+* `ssh_username` (string) - The SSH username. Defaults to "root".
+
+* `state_timeout` (string) - The time to wait for instance state changes.
+  Defaults to "5m".
+
+## Gotchas
+
+Centos images have root ssh access disabled by default. Set `ssh_username` to any user, which will be created by packer with sudo access.
+
+The machine type must have a scratch disk, which means you can't use an `f1-micro` or `g1-small` to build images.

website/source/layouts/docs.erb

@@ -33,6 +33,7 @@
 			<li><a href="/docs/builders/amazon.html">Amazon EC2 (AMI)</a></li>
 			<li><a href="/docs/builders/digitalocean.html">DigitalOcean</a></li>
 			<li><a href="/docs/builders/docker.html">Docker</a></li>
+			<li><a href="/docs/builders/googlecompute.html">Google Compute Engine</a></li>
 			<li><a href="/docs/builders/openstack.html">OpenStack</a></li>
 			<li><a href="/docs/builders/qemu.html">QEMU</a></li>
 			<li><a href="/docs/builders/virtualbox.html">VirtualBox</a></li>

website/source/stylesheets/_components.scss

@@ -174,7 +174,6 @@ header .header {
 
             ul,
             ol {
-                list-style-type: circle;
                 list-style-position: inside;
                 margin-top: $baseline;
                 margin-left: 20px;
@@ -188,6 +187,14 @@ header .header {
                 }
             }
 
+            ul {
+                list-style-type: circle;
+            }
+
+            ol {
+                list-style-type: decimal;
+            }
+
             div.alert {
                 font-family: $serif;
                 font-size: 17px;