Add 'create_image' option to googlecompute

When building a CI/CD deployment, during the PR process it's nice to be
able to run the builder, but not create the image the build produces.

Closes #9965

builder/googlecompute/config.go

@@ -17,6 +17,7 @@ import (
 	"github.com/hashicorp/packer/helper/config"
 	"github.com/hashicorp/packer/packer"
 	"github.com/hashicorp/packer/template/interpolate"
+	"github.com/mitchellh/mapstructure"
 	compute "google.golang.org/api/compute/v1"
 )
 
@@ -76,6 +77,8 @@ type Config struct {
 	EnableIntegrityMonitoring bool `mapstructure:"enable_integrity_monitoring" required:"false"`
 	// Whether to use an IAP proxy.
 	IAPConfig `mapstructure:",squash"`
+	// Create the image. Useful for setting to `false` during a build test stage. Defaults to `true`.
+	CreateImage bool `mapstructure:"create_image" required:"false"`
 	// The unique name of the resulting image. Defaults to
 	// `packer-{{timestamp}}`.
 	ImageName string `mapstructure:"image_name" required:"false"`
@@ -288,7 +291,9 @@ type Config struct {
 
 func (c *Config) Prepare(raws ...interface{}) ([]string, error) {
 	c.ctx.Funcs = TemplateFuncs
+	var md mapstructure.Metadata
 	err := config.Decode(c, &config.DecodeOpts{
+		Metadata:           &md,
 		Interpolate:        true,
 		InterpolateContext: &c.ctx,
 		InterpolateFilter: &interpolate.RenderFilter{
@@ -329,6 +334,18 @@ func (c *Config) Prepare(raws ...interface{}) ([]string, error) {
 		}
 	}
 
+	hasCreateImage := false
+	for _, k := range md.Keys {
+		if k == "create_image" {
+			hasCreateImage = true
+			break
+		}
+	}
+
+	if !hasCreateImage {
+		c.CreateImage = true
+	}
+
 	if c.ImageDescription == "" {
 		c.ImageDescription = "Created by Packer"
 	}

builder/googlecompute/config.hcl2spec.go

@@ -81,6 +81,7 @@ type FlatConfig struct {
 	IAPHashBang                  *string                    `mapstructure:"iap_hashbang" required:"false" cty:"iap_hashbang" hcl:"iap_hashbang"`
 	IAPExt                       *string                    `mapstructure:"iap_ext" required:"false" cty:"iap_ext" hcl:"iap_ext"`
 	IAPTunnelLaunchWait          *int                       `mapstructure:"iap_tunnel_launch_wait" required:"false" cty:"iap_tunnel_launch_wait" hcl:"iap_tunnel_launch_wait"`
+	CreateImage                  *bool                      `mapstructure:"create_image" required:"false" cty:"create_image" hcl:"create_image"`
 	ImageName                    *string                    `mapstructure:"image_name" required:"false" cty:"image_name" hcl:"image_name"`
 	ImageDescription             *string                    `mapstructure:"image_description" required:"false" cty:"image_description" hcl:"image_description"`
 	ImageEncryptionKey           *FlatCustomerEncryptionKey `mapstructure:"image_encryption_key" required:"false" cty:"image_encryption_key" hcl:"image_encryption_key"`
@@ -200,6 +201,7 @@ func (*FlatConfig) HCL2Spec() map[string]hcldec.Spec {
 		"iap_hashbang":                    &hcldec.AttrSpec{Name: "iap_hashbang", Type: cty.String, Required: false},
 		"iap_ext":                         &hcldec.AttrSpec{Name: "iap_ext", Type: cty.String, Required: false},
 		"iap_tunnel_launch_wait":          &hcldec.AttrSpec{Name: "iap_tunnel_launch_wait", Type: cty.Number, Required: false},
+		"create_image":                    &hcldec.AttrSpec{Name: "create_image", Type: cty.Bool, Required: false},
 		"image_name":                      &hcldec.AttrSpec{Name: "image_name", Type: cty.String, Required: false},
 		"image_description":               &hcldec.AttrSpec{Name: "image_description", Type: cty.String, Required: false},
 		"image_encryption_key":            &hcldec.BlockSpec{TypeName: "image_encryption_key", Nested: hcldec.ObjectSpec((*FlatCustomerEncryptionKey)(nil).HCL2Spec())},

builder/googlecompute/step_create_image.go

@@ -23,6 +23,11 @@ func (s *StepCreateImage) Run(ctx context.Context, state multistep.StateBag) mul
 	driver := state.Get("driver").(Driver)
 	ui := state.Get("ui").(packer.Ui)
 
+	if !config.CreateImage {
+		ui.Say("Skipping image creation...")
+		return multistep.ActionContinue
+	}
+
 	if config.PackerForce && config.imageAlreadyExists {
 		ui.Say("Deleting previous image...")
 

website/pages/partials/builder/googlecompute/Config-not-required.mdx

@@ -42,6 +42,8 @@
   state of your VM instances. Note: integrity monitoring relies on having
   vTPM enabled. [Details](https://cloud.google.com/security/shielded-cloud/shielded-vm)
 
+- `create_image` (bool) - Create the image. Useful for setting to `false` during a build test stage. Defaults to `true`.
+
 - `image_name` (string) - The unique name of the resulting image. Defaults to
   `packer-{{timestamp}}`.