feat: support zstd compression (#125)

Closes #122

cmd/upload.go

@@ -121,10 +121,10 @@ func init() {
 	uploadCmd.MarkFlagsMutuallyExclusive(uploadFlagImageURL, uploadFlagImagePath)
 	uploadCmd.MarkFlagsOneRequired(uploadFlagImageURL, uploadFlagImagePath)
 
-	uploadCmd.Flags().String(uploadFlagCompression, "", "Type of compression that was used on the disk image [choices: bz2, xz]")
+	uploadCmd.Flags().String(uploadFlagCompression, "", "Type of compression that was used on the disk image [choices: bz2, xz, zstd]")
 	_ = uploadCmd.RegisterFlagCompletionFunc(
 		uploadFlagCompression,
-		cobra.FixedCompletions([]string{string(hcloudimages.CompressionBZ2), string(hcloudimages.CompressionXZ)}, cobra.ShellCompDirectiveNoFileComp),
+		cobra.FixedCompletions([]string{string(hcloudimages.CompressionBZ2), string(hcloudimages.CompressionXZ), string(hcloudimages.CompressionZSTD)}, cobra.ShellCompDirectiveNoFileComp),
 	)
 
 	uploadCmd.Flags().String(uploadFlagFormat, "", "Format of the image. [choices: qcow2]")

docs/reference/cli/hcloud-upload-image_upload.md

@@ -34,7 +34,7 @@ hcloud-upload-image upload (--image-path=<local-path> | --image-url=<url>) --arc
 
 ```
       --architecture string     CPU architecture of the disk image [choices: x86, arm]
-      --compression string      Type of compression that was used on the disk image [choices: bz2, xz]
+      --compression string      Type of compression that was used on the disk image [choices: bz2, xz, zstd]
       --description string      Description for the resulting image
       --format string           Format of the image. [choices: qcow2]
   -h, --help                    help for upload

hcloudimages/client.go

@@ -104,9 +104,10 @@ const (
 	CompressionNone Compression = ""
 	CompressionBZ2  Compression = "bz2"
 	CompressionXZ   Compression = "xz"
+	CompressionZSTD Compression = "zstd"
 
 	// Possible future additions:
-	// zip,zstd
+	// zip
 )
 
 type Format string
@@ -524,6 +525,8 @@ func assembleCommand(options UploadOptions) (string, error) {
 			cmd += "bzip2 -cd | "
 		case CompressionXZ:
 			cmd += "xz -cd | "
+		case CompressionZSTD:
+			cmd += "zstd -cd | "
 		default:
 			return "", fmt.Errorf("unknown compression: %q", options.ImageCompression)
 		}

hcloudimages/client_test.go

@@ -48,6 +48,21 @@ func TestAssembleCommand(t *testing.T) {
 			},
 			want: "bash -c 'set -euo pipefail && wget --no-verbose -O - \"https://example.com/image.xz\" | xz -cd | dd of=/dev/sda bs=4M && sync'",
 		},
+		{
+			name: "local zstd",
+			options: UploadOptions{
+				ImageCompression: CompressionZSTD,
+			},
+			want: "bash -c 'set -euo pipefail && zstd -cd | dd of=/dev/sda bs=4M && sync'",
+		},
+		{
+			name: "remote zstd",
+			options: UploadOptions{
+				ImageURL:         mustParseURL("https://example.com/image.zst"),
+				ImageCompression: CompressionZSTD,
+			},
+			want: "bash -c 'set -euo pipefail && wget --no-verbose -O - \"https://example.com/image.zst\" | zstd -cd | dd of=/dev/sda bs=4M && sync'",
+		},
 		{
 			name: "local bz2",
 			options: UploadOptions{
@@ -59,9 +74,9 @@ func TestAssembleCommand(t *testing.T) {
 			name: "remote bz2",
 			options: UploadOptions{
 				ImageURL:         mustParseURL("https://example.com/image.bz2"),
-				ImageCompression: CompressionXZ,
+				ImageCompression: CompressionBZ2,
 			},
-			want: "bash -c 'set -euo pipefail && wget --no-verbose -O - \"https://example.com/image.bz2\" | xz -cd | dd of=/dev/sda bs=4M && sync'",
+			want: "bash -c 'set -euo pipefail && wget --no-verbose -O - \"https://example.com/image.bz2\" | bzip2 -cd | dd of=/dev/sda bs=4M && sync'",
 		},
 		{
 			name: "local qcow2",