fix: overlay installer operations

1. Use overlay installer to build the `cmdline` when running in
   install/upgrade mode.

2. Pull down the overlay installer with the arch specific to the
   installer being generated, vs. the arch of the `imager`.

3. Print a message when running an overlay installer.

Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>

cmd/installer/cmd/imager/root.go

@@ -124,6 +124,8 @@ var rootCmd = &cobra.Command{
 						},
 						ExtraOptions: extraOverlayOptions,
 					}
+
+					prof.Input.OverlayInstaller.ImageRef = cmdFlags.OverlayImage
 				}
 
 				prof.Input.SystemExtensions = xslices.Map(

cmd/installer/cmd/installer/root.go

@@ -48,16 +48,21 @@ func Execute() {
 	}
 }
 
-var options = &install.Options{}
+var options = &install.Options{
+	Board: constants.BoardNone,
+}
 
-var bootloader bool
+var (
+	bootloader bool
+	dummy      string
+)
 
 func init() {
 	rootCmd.PersistentFlags().StringVar(&options.ConfigSource, "config", "", "The value of "+constants.KernelParamConfig)
 	rootCmd.PersistentFlags().StringVar(&options.Disk, "disk", "", "The path to the disk to install to")
 	rootCmd.PersistentFlags().StringVar(&options.Platform, "platform", "", "The value of "+constants.KernelParamPlatform)
 	rootCmd.PersistentFlags().StringVar(&options.Arch, "arch", runtime.GOARCH, "The target architecture")
-	rootCmd.PersistentFlags().StringVar(&options.Board, "board", constants.BoardNone, "Deprecated: no op")
+	rootCmd.PersistentFlags().StringVar(&dummy, "board", constants.BoardNone, "Deprecated: no op")
 	rootCmd.PersistentFlags().StringArrayVar(&options.ExtraKernelArgs, "extra-kernel-arg", []string{}, "Extra argument to pass to the kernel")
 	rootCmd.PersistentFlags().BoolVar(&bootloader, "bootloader", true, "Deprecated: no op")
 	rootCmd.PersistentFlags().BoolVar(&options.Upgrade, "upgrade", false, "Indicates that the install is being performed by an upgrade")

cmd/installer/pkg/install/install.go

@@ -47,6 +47,7 @@ type Options struct {
 	LegacyBIOSSupport   bool
 	MetaValues          MetaValues
 	OverlayInstaller    overlay.Installer[overlay.ExtraOptions]
+	OverlayName         string
 	OverlayExtractedDir string
 	ExtraOptions        overlay.ExtraOptions
 
@@ -85,6 +86,25 @@ func Install(ctx context.Context, p runtime.Platform, mode Mode, opts *Options)
 		return fmt.Errorf("using standard installer image is not supported for board: %s, use an installer with overlay", b)
 	}
 
+	if overlayPresent {
+		extraOptionsBytes, err := os.ReadFile(constants.ImagerOverlayExtraOptionsPath)
+		if err != nil {
+			return err
+		}
+
+		var extraOptions overlay.ExtraOptions
+
+		decoder := yaml.NewDecoder(bytes.NewReader(extraOptionsBytes))
+		decoder.KnownFields(true)
+
+		if err := decoder.Decode(&extraOptions); err != nil {
+			return fmt.Errorf("failed to decode extra options: %w", err)
+		}
+
+		opts.OverlayInstaller = executor.New(constants.ImagerOverlayInstallerDefaultPath)
+		opts.ExtraOptions = extraOptions
+	}
+
 	cmdline := procfs.NewCmdline("")
 	cmdline.Append(constants.KernelParamPlatform, p.Name())
 
@@ -117,6 +137,17 @@ func Install(ctx context.Context, p runtime.Platform, mode Mode, opts *Options)
 		cmdline.SetAll(b.KernelArgs().Strings())
 	}
 
+	if opts.OverlayInstaller != nil {
+		overlayOpts, getOptsErr := opts.OverlayInstaller.GetOptions(opts.ExtraOptions)
+		if getOptsErr != nil {
+			return fmt.Errorf("failed to get overlay installer options: %w", getOptsErr)
+		}
+
+		opts.OverlayName = overlayOpts.Name
+
+		cmdline.SetAll(overlayOpts.KernelArgs)
+	}
+
 	if err := cmdline.AppendAll(
 		opts.ExtraKernelArgs,
 		procfs.WithOverwriteArgs("console"),
@@ -126,25 +157,6 @@ func Install(ctx context.Context, p runtime.Platform, mode Mode, opts *Options)
 		return err
 	}
 
-	if overlayPresent {
-		extraOptionsBytes, err := os.ReadFile(constants.ImagerOverlayExtraOptionsPath)
-		if err != nil {
-			return err
-		}
-
-		var extraOptions overlay.ExtraOptions
-
-		decoder := yaml.NewDecoder(bytes.NewReader(extraOptionsBytes))
-		decoder.KnownFields(true)
-
-		if err := decoder.Decode(&extraOptions); err != nil {
-			return fmt.Errorf("failed to decode extra options: %w", err)
-		}
-
-		opts.OverlayInstaller = executor.New(constants.ImagerOverlayInstallerDefaultPath)
-		opts.ExtraOptions = extraOptions
-	}
-
 	i, err := NewInstaller(ctx, cmdline, mode, opts)
 	if err != nil {
 		return err
@@ -338,6 +350,8 @@ func (i *Installer) Install(ctx context.Context, mode Mode) (err error) {
 	}
 
 	if i.options.OverlayInstaller != nil {
+		i.options.Printf("running overlay installer %q", i.options.OverlayName)
+
 		if err = i.options.OverlayInstaller.Install(overlay.InstallOptions[overlay.ExtraOptions]{
 			InstallDisk:   i.options.Disk,
 			MountPrefix:   i.options.MountPrefix,

pkg/imager/out.go

@@ -411,6 +411,21 @@ func (i *Imager) outInstaller(ctx context.Context, path string, report *reporter
 	}
 
 	if i.overlayInstaller != nil {
+		tempOverlayPath := filepath.Join(i.tempDir, "overlay-installer", constants.ImagerOverlayBasePath)
+
+		if err := os.MkdirAll(tempOverlayPath, 0o755); err != nil {
+			return fmt.Errorf("failed to create overlay directory: %w", err)
+		}
+
+		if err := i.prof.Input.OverlayInstaller.Extract(
+			ctx,
+			tempOverlayPath,
+			i.prof.Arch,
+			progressPrintf(report, reporter.Update{Message: "pulling overlay for installer...", Status: reporter.StatusRunning}),
+		); err != nil {
+			return err
+		}
+
 		extraOpts, internalErr := yaml.Marshal(i.prof.Overlay.ExtraOptions)
 		if internalErr != nil {
 			return fmt.Errorf("failed to marshal extra options: %w", internalErr)
@@ -430,11 +445,11 @@ func (i *Imager) outInstaller(ctx context.Context, path string, report *reporter
 			mode       os.FileMode
 		}{
 			{
-				sourcePath: filepath.Join(i.tempDir, constants.ImagerOverlayArtifactsPath),
+				sourcePath: filepath.Join(i.tempDir, "overlay-installer", constants.ImagerOverlayArtifactsPath),
 				imagePath:  strings.TrimLeft(constants.ImagerOverlayArtifactsPath, "/"),
 			},
 			{
-				sourcePath: filepath.Join(i.tempDir, constants.ImagerOverlayInstallersPath, i.prof.Overlay.Name),
+				sourcePath: filepath.Join(i.tempDir, "overlay-installer", constants.ImagerOverlayInstallersPath, i.prof.Overlay.Name),
 				imagePath:  strings.TrimLeft(constants.ImagerOverlayInstallerDefaultPath, "/"),
 				mode:       0o755,
 			},

pkg/imager/profile/input.go

@@ -54,6 +54,10 @@ type Input struct {
 	RPiFirmware FileAsset `yaml:"rpiFirmware,omitempty"`
 	// Base installer image to mutate.
 	BaseInstaller ContainerAsset `yaml:"baseInstaller,omitempty"`
+	// OverlayInstaller is an overlay image to inject into the installer.
+	//
+	// OverlayInstaller architecture should match the output installer architecture.
+	OverlayInstaller ContainerAsset `yaml:"overlayInstaller,omitempty"`
 	// SecureBoot is a section with secureboot keys, only for SecureBoot enabled builds.
 	SecureBoot *SecureBootAssets `yaml:"secureboot,omitempty"`
 	// SystemExtensions is a list of system extensions to install.