ore/azure: support building aarch64 images

Add a flag to create-gallery-image to allow setting the architecture
to aarch64 (Arm64). The Azure SDK for Go only supports setting the arch
when creating gallery images.

Author: marmijo

mantle/cmd/ore/azure/create-gallery-image.go

@@ -36,6 +36,7 @@ var (
 
 	galleryImageName string
 	galleryName      string
+	architecture     string
 )
 
 func init() {
@@ -45,6 +46,7 @@ func init() {
 	sv(&galleryName, "gallery-name", "kola", "gallery name")
 	sv(&blobUrl, "image-blob", "", "source blob url")
 	sv(&resourceGroup, "resource-group", "kola", "resource group name")
+	sv(&architecture, "arch", "", "The target architecture for the image")
 
 	Azure.AddCommand(cmdCreateGalleryImage)
 }
@@ -71,7 +73,7 @@ func runCreateGalleryImage(cmd *cobra.Command, args []string) error {
 	}
 	sourceImageId := *img.ID
 
-	galleryImage, err := api.CreateGalleryImage(galleryImageName, galleryName, resourceGroup, sourceImageId)
+	galleryImage, err := api.CreateGalleryImage(galleryImageName, galleryName, resourceGroup, sourceImageId, architecture)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Couldn't create Azure Shared Image Gallery image: %v\n", err)
 		os.Exit(1)

mantle/platform/api/azure/gallery.go

@@ -18,6 +18,7 @@ package azure
 import (
 	"context"
 	"fmt"
+	"runtime"
 	"time"
 
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore/to"
@@ -26,7 +27,7 @@ import (
 	"github.com/coreos/coreos-assembler/mantle/util"
 )
 
-func (a *API) CreateGalleryImage(name, galleryName, resourceGroup, sourceImageID string) (armcompute.GalleryImageVersion, error) {
+func (a *API) CreateGalleryImage(name, galleryName, resourceGroup, sourceImageID, architecture string) (armcompute.GalleryImageVersion, error) {
 	ctx := context.Background()
 
 	// Ensure the Azure Shared Image Gallery exists. BeginCreateOrUpdate will create the gallery
@@ -54,6 +55,19 @@ func (a *API) CreateGalleryImage(name, galleryName, resourceGroup, sourceImageID
 		},
 	}
 
+	var azureArch armcompute.Architecture
+	if architecture == "" {
+		architecture = runtime.GOARCH
+	}
+	switch architecture {
+	case "amd64", "x86_64":
+		azureArch = armcompute.ArchitectureX64
+	case "arm64", "aarch64":
+		azureArch = armcompute.ArchitectureArm64
+	default:
+		return armcompute.GalleryImageVersion{}, fmt.Errorf("unsupported azure architecture %q", architecture)
+	}
+
 	// Create a Gallery Image Definition with the specified Hyper-V generation (V1 or V2).
 	galleryImagePoller, err := a.galImgClient.BeginCreateOrUpdate(ctx, resourceGroup, galleryName, name, armcompute.GalleryImage{
 		Location: &a.opts.Location,
@@ -66,7 +80,8 @@ func (a *API) CreateGalleryImage(name, galleryName, resourceGroup, sourceImageID
 				Offer:     to.Ptr(name),
 				SKU:       to.Ptr(util.RandomName("sku")),
 			},
-			Features: galleryImageFeatures,
+			Features:     galleryImageFeatures,
+			Architecture: &azureArch,
 		},
 	}, nil)
 	if err != nil {