ore/aws: add helper to get AWS snapshot size

Add `FindSnapshotDiskSizeGiB` to retrieve the volume size for a given
snapshot ID, to be used when a snapshot is provided for AMI creation.

Author: marmijo

mantle/cmd/ore/aws/upload.go

@@ -157,6 +157,7 @@ func runUpload(cmd *cobra.Command, args []string) error {
 		os.Exit(2)
 	}
 
+	var err error
 	if uploadDiskSizeInspect {
 		imageInfo, err := util.GetImageInfo(uploadFile)
 		if err != nil {
@@ -172,8 +173,15 @@ func runUpload(cmd *cobra.Command, args []string) error {
 		}
 	}
 
+	if uploadSourceSnapshot != "" {
+		uploadDiskSizeGiB, err = API.FindSnapshotDiskSizeGiB(uploadSourceSnapshot)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Unable to query size of disk from snapshot: %v\n", err)
+			os.Exit(1)
+		}
+	}
+
 	var s3URL *url.URL
-	var err error
 	if uploadSourceObject != "" {
 		s3URL, err = url.Parse(uploadSourceObject)
 		if err != nil {

mantle/platform/api/aws/images.go

@@ -852,3 +852,18 @@ func getImageSnapshotID(image *ec2.Image) (string, error) {
 	// and it's just a sorta eventual consistency thing
 	return "", fmt.Errorf("no backing block device for %v", image.ImageId)
 }
+
+func (a *API) FindSnapshotDiskSizeGiB(snapshotID string) (uint, error) {
+	result, err := a.ec2.DescribeSnapshots(&ec2.DescribeSnapshotsInput{
+		SnapshotIds: []*string{&snapshotID},
+	})
+	if err != nil {
+		return 0, fmt.Errorf("failed to describe snapshot: %v", err)
+	}
+
+	if len(result.Snapshots) == 0 {
+		return 0, fmt.Errorf("no snapshot found with ID %s", snapshotID)
+	}
+
+	return uint(aws.Int64Value(result.Snapshots[0].VolumeSize)), nil
+}

src/cosalib/aws.py

@@ -157,9 +157,7 @@ def aws_run_ore(build, args):
             '--billing-product-code', f"{args.winli_billing_product}"
         ])
     else:
-        ore_args.extend([
-            '--disk-size-inspect'
-        ])
+        ore_args.extend(['--disk-size-inspect'])
         winli_name = ""
         winli_description = ""
         buildmeta_key = "amis"