Add openstack image min_disk option

builder/openstack/builder.go

@@ -153,6 +153,7 @@ func (b *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (pack
 		&stepUpdateImageTags{},
 		&stepUpdateImageVisibility{},
 		&stepAddImageMembers{},
+		&stepUpdateImageMinDisk{},
 	}
 
 	// Run!

builder/openstack/image_config.go

@@ -16,6 +16,7 @@ type ImageConfig struct {
 	ImageMembers    []string                     `mapstructure:"image_members"`
 	ImageDiskFormat string                       `mapstructure:"image_disk_format"`
 	ImageTags       []string                     `mapstructure:"image_tags"`
+	ImageMinDisk    int                          `mapstructure:"image_min_disk"`
 }
 
 func (c *ImageConfig) Prepare(ctx *interpolate.Context) []error {
@@ -52,6 +53,10 @@ func (c *ImageConfig) Prepare(ctx *interpolate.Context) []error {
 		}
 	}
 
+	if c.ImageMinDisk < 0 {
+		errs = append(errs, fmt.Errorf("An image min disk size must be greater than or equal to 0"))
+	}
+
 	if len(errs) > 0 {
 		return errs
 	}

builder/openstack/step_update_image_mindisk.go

@@ -0,0 +1,52 @@
+package openstack
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/gophercloud/gophercloud/openstack/imageservice/v2/images"
+	"github.com/hashicorp/packer/helper/multistep"
+	"github.com/hashicorp/packer/packer"
+)
+
+type stepUpdateImageMinDisk struct{}
+
+func (s *stepUpdateImageMinDisk) Run(_ context.Context, state multistep.StateBag) multistep.StepAction {
+	imageId := state.Get("image").(string)
+	ui := state.Get("ui").(packer.Ui)
+	config := state.Get("config").(*Config)
+
+	if config.ImageMinDisk == 0 {
+		return multistep.ActionContinue
+	}
+	imageClient, err := config.imageV2Client()
+	if err != nil {
+		err := fmt.Errorf("Error initializing image service client: %s", err)
+		state.Put("error", err)
+		return multistep.ActionHalt
+	}
+
+	ui.Say(fmt.Sprintf("Updatind image min disk to %d", config.ImageMinDisk))
+
+	r := images.Update(
+		imageClient,
+		imageId,
+		images.UpdateOpts{
+			images.ReplaceImageMinDisk{
+				NewMinDisk: config.ImageMinDisk,
+			},
+		},
+	)
+
+	if _, err := r.Extract(); err != nil {
+		err = fmt.Errorf("Error updating image min disk: %s", err)
+		state.Put("error", err)
+		return multistep.ActionHalt
+	}
+
+	return multistep.ActionContinue
+}
+
+func (s *stepUpdateImageMinDisk) Cleanup(multistep.StateBag) {
+	// No cleanup...
+}

website/source/docs/builders/openstack.html.md

@@ -144,6 +144,8 @@ builder.
     after creation. An image member is usually a project (also called the
     "tenant") with whom the image is shared.
 
+-   `image_min_disk` (int) - Minimum disk of needed to boot image size in GB. 
+
 -   `image_tags` (array of strings) - List of tags to add to the image after
     creation.