manifest: support specifying force_size for VPC

The RHEL 7 vpc subformat in qemu does not support force_size so we need
to be able to disable it.  The parameter in all parts is defined as a
pointer because the default value is 'true'.  Not specifying it will
keep the option in the osbuild stage as 'nil', falling back to 'true' in
osbuild.

internal/distro/rhel7/images.go

@@ -4,6 +4,7 @@ import (
 	"math/rand"
 
 	"github.com/osbuild/osbuild-composer/internal/blueprint"
+	"github.com/osbuild/osbuild-composer/internal/common"
 	"github.com/osbuild/osbuild-composer/internal/container"
 	"github.com/osbuild/osbuild-composer/internal/distro"
 	"github.com/osbuild/osbuild-composer/internal/image"
@@ -181,8 +182,9 @@ func liveImage(workload workload.Workload,
 	img.Environment = t.environment
 	img.Workload = workload
 	img.Compression = t.compression
-	img.PartTool = osbuild.PTSgdisk // all RHEL 7 images should use sgdisk
-	img.NoBLS = true                // RHEL 7 grub does not support BLS
+	img.PartTool = osbuild.PTSgdisk     // all RHEL 7 images should use sgdisk
+	img.ForceSize = common.ToPtr(false) // RHEL 7 qemu vpc subformat does not support force_size
+	img.NoBLS = true                    // RHEL 7 grub does not support BLS
 	img.OSProduct = t.arch.distro.product
 	img.OSVersion = t.arch.distro.osVersion
 	img.OSNick = t.arch.distro.nick

internal/image/live.go

@@ -25,6 +25,7 @@ type LiveImage struct {
 	Workload         workload.Workload
 	Filename         string
 	Compression      string
+	ForceSize        *bool
 	PartTool         osbuild.PartTool
 
 	NoBLS     bool
@@ -82,6 +83,7 @@ func (img *LiveImage) InstantiateManifest(m *manifest.Manifest,
 		if img.Compression == "" {
 			vpcPipeline.Filename = img.Filename
 		}
+		vpcPipeline.ForceSize = img.ForceSize
 		artifactPipeline = vpcPipeline
 		artifact = vpcPipeline.Export()
 	case platform.FORMAT_VMDK:

internal/manifest/vpc.go

@@ -10,6 +10,8 @@ type VPC struct {
 	Base
 	Filename string
 
+	ForceSize *bool
+
 	imgPipeline *RawImage
 }
 
@@ -35,8 +37,10 @@ func NewVPC(m *Manifest,
 func (p *VPC) serialize() osbuild.Pipeline {
 	pipeline := p.Base.serialize()
 
+	formatOptions := osbuild.VPCOptions{ForceSize: p.ForceSize}
+
 	pipeline.AddStage(osbuild.NewQEMUStage(
-		osbuild.NewQEMUStageOptions(p.Filename, osbuild.QEMUFormatVPC, nil),
+		osbuild.NewQEMUStageOptions(p.Filename, osbuild.QEMUFormatVPC, formatOptions),
 		osbuild.NewQemuStagePipelineFilesInputs(p.imgPipeline.Name(), p.imgPipeline.Filename),
 	))