fix: imager should support different Talos versions

Add some quirks to make images generated with newer Talos compatible
with images generated by older Talos.

Specifically, reset options were adding in Talos 1.4, so we shouldn't
add them for older versions.

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

cmd/installer/pkg/install/install.go

@@ -157,7 +157,7 @@ func NewInstaller(ctx context.Context, cmdline *procfs.Cmdline, mode Mode, opts
 	if !bootLoaderPresent {
 		if mode.IsImage() {
 			// on image creation, use the bootloader based on options
-			i.bootloader = bootloader.New(opts.ImageSecureboot)
+			i.bootloader = bootloader.New(opts.ImageSecureboot, opts.Version)
 		} else {
 			// on install/upgrade perform automatic detection
 			i.bootloader = bootloader.NewAuto()

internal/app/machined/pkg/runtime/v1alpha1/bootloader/bootloader.go

@@ -12,6 +12,7 @@ import (
 	"github.com/siderolabs/talos/internal/app/machined/pkg/runtime/v1alpha1/bootloader/grub"
 	"github.com/siderolabs/talos/internal/app/machined/pkg/runtime/v1alpha1/bootloader/options"
 	"github.com/siderolabs/talos/internal/app/machined/pkg/runtime/v1alpha1/bootloader/sdboot"
+	"github.com/siderolabs/talos/pkg/imager/quirks"
 )
 
 // Bootloader describes a bootloader.
@@ -62,10 +63,13 @@ func NewAuto() Bootloader {
 }
 
 // New returns a new bootloader based on the secureboot flag.
-func New(secureboot bool) Bootloader {
+func New(secureboot bool, talosVersion string) Bootloader {
 	if secureboot {
 		return sdboot.New()
 	}
 
-	return grub.NewConfig()
+	g := grub.NewConfig()
+	g.AddResetOption = quirks.New(talosVersion).SupportsResetGRUBOption()
+
+	return g
 }

internal/app/machined/pkg/runtime/v1alpha1/bootloader/grub/decode.go

@@ -69,44 +69,48 @@ func Decode(c []byte) (*Config, error) {
 		return nil, err
 	}
 
-	entries, err := parseEntries(c)
+	entries, hasResetOption, err := parseEntries(c)
 	if err != nil {
 		return nil, err
 	}
 
 	conf := Config{
-		Default:  defaultEntry,
+		Default:        defaultEntry,
-		Fallback: fallbackEntry,
+		Fallback:       fallbackEntry,
-		Entries:  entries,
+		Entries:        entries,
+		AddResetOption: hasResetOption,
 	}
 
 	return &conf, nil
 }
 
-func parseEntries(conf []byte) (map[BootLabel]MenuEntry, error) {
+func parseEntries(conf []byte) (map[BootLabel]MenuEntry, bool, error) {
 	entries := make(map[BootLabel]MenuEntry)
+	hasResetOption := false
 
 	matches := menuEntryRegex.FindAllSubmatch(conf, -1)
 	for _, m := range matches {
 		if len(m) != 3 {
-			return nil, fmt.Errorf("conf block: expected 3 matches, got %d", len(m))
+			return nil, false, fmt.Errorf("conf block: expected 3 matches, got %d", len(m))
 		}
 
 		confBlock := m[2]
 
 		linux, cmdline, initrd, err := parseConfBlock(confBlock)
 		if err != nil {
-			return nil, err
+			return nil, false, err
 		}
 
 		name := string(m[1])
 
 		bootEntry, err := ParseBootLabel(name)
 		if err != nil {
-			return nil, err
+			return nil, false, err
 		}
 
 		if bootEntry == BootReset {
+			hasResetOption = true
+
 			continue
 		}
 
@@ -118,7 +122,7 @@ func parseEntries(conf []byte) (map[BootLabel]MenuEntry, error) {
 		}
 	}
 
-	return entries, nil
+	return entries, hasResetOption, nil
 }
 
 func parseConfBlock(block []byte) (linux, cmdline, initrd string, err error) {

internal/app/machined/pkg/runtime/v1alpha1/bootloader/grub/encode.go

@@ -32,6 +32,7 @@ menuentry "{{ $entry.Name }}" {
 }
 {{ end -}}
 
+{{ if .AddResetOption -}}
 {{ $defaultEntry := index .Entries .Default -}}
 menuentry "Reset Talos installation and return to maintenance mode" {
   set gfxmode=auto
@@ -39,6 +40,7 @@ menuentry "Reset Talos installation and return to maintenance mode" {
   linux {{ $defaultEntry.Linux }} {{ quote $defaultEntry.Cmdline }} talos.experimental.wipe=system:EPHEMERAL,STATE
   initrd {{ $defaultEntry.Initrd }}
 }
+{{ end -}}
 `
 
 // Write the grub configuration to the given file.

internal/app/machined/pkg/runtime/v1alpha1/bootloader/grub/grub.go

@@ -15,9 +15,10 @@ import (
 
 // Config represents a grub configuration file (grub.cfg).
 type Config struct {
-	Default  BootLabel
+	Default        BootLabel
-	Fallback BootLabel
+	Fallback       BootLabel
-	Entries  map[BootLabel]MenuEntry
+	Entries        map[BootLabel]MenuEntry
+	AddResetOption bool
 }
 
 // MenuEntry represents a grub menu entry in the grub config file.
@@ -35,8 +36,9 @@ func (e bootloaderNotInstalledError) Error() string {
 // NewConfig creates a new grub configuration (nothing is written to disk).
 func NewConfig() *Config {
 	return &Config{
-		Default: BootA,
+		Default:        BootA,
-		Entries: map[BootLabel]MenuEntry{},
+		Entries:        map[BootLabel]MenuEntry{},
+		AddResetOption: true,
 	}
 }
 

internal/app/machined/pkg/runtime/v1alpha1/bootloader/grub/grub_test.go

@@ -28,6 +28,9 @@ var (
 
 	//go:embed testdata/grub_write_test.cfg
 	newConfig string
+
+	//go:embed testdata/grub_write_no_reset_test.cfg
+	newNoResetConfig string
 )
 
 func TestDecode(t *testing.T) {
@@ -50,6 +53,8 @@ func TestDecode(t *testing.T) {
 	assert.Equal(t, "cmdline B", b.Cmdline)
 	assert.True(t, strings.HasPrefix(b.Linux, "/B/"))
 	assert.True(t, strings.HasPrefix(b.Initrd, "/B/"))
+
+	assert.True(t, conf.AddResetOption)
 }
 
 func TestEncodeDecode(t *testing.T) {
@@ -110,6 +115,31 @@ func TestWrite(t *testing.T) {
 	assert.Equal(t, newConfig, string(written))
 }
 
+//nolint:errcheck
+func TestWriteNoReset(t *testing.T) {
+	oldName := version.Name
+
+	t.Cleanup(func() {
+		version.Name = oldName
+	})
+
+	version.Name = "TestOld"
+
+	tempFile, _ := os.CreateTemp("", "talos-test-grub-*.cfg")
+
+	t.Cleanup(func() { require.NoError(t, os.Remove(tempFile.Name())) })
+
+	config := grub.NewConfig()
+	config.AddResetOption = false
+	require.NoError(t, config.Put(grub.BootA, "cmdline A", "v0.0.1"))
+
+	err := config.Write(tempFile.Name(), t.Logf)
+	assert.NoError(t, err)
+
+	written, _ := os.ReadFile(tempFile.Name())
+	assert.Equal(t, newNoResetConfig, string(written))
+}
+
 func TestPut(t *testing.T) {
 	config := grub.NewConfig()
 	require.NoError(t, config.Put(grub.BootA, "cmdline A", "v1.2.3"))

internal/app/machined/pkg/runtime/v1alpha1/bootloader/grub/testdata/grub_write_no_reset_test.cfg

@@ -0,0 +1,15 @@
+set default="A - TestOld v0.0.1"
+
+set timeout=3
+
+insmod all_video
+
+terminal_input console
+terminal_output console
+
+menuentry "A - TestOld v0.0.1" {
+  set gfxmode=auto
+  set gfxpayload=text
+  linux /A/vmlinuz cmdline A
+  initrd /A/initramfs.xz
+}

pkg/imager/iso/grub.cfg

@@ -13,9 +13,11 @@ menuentry "Talos ISO" {
 	initrd /boot/initramfs.xz
 }
 
+{{ if .AddResetOption -}}
 menuentry "Reset Talos installation" {
 	set gfxmode=auto
 	set gfxpayload=text
 	linux /boot/vmlinuz {{ quote .Cmdline }} talos.experimental.wipe=system
 	initrd /boot/initramfs.xz
 }
+{{ end -}}

pkg/imager/iso/grub.go

@@ -16,6 +16,7 @@ import (
 	"github.com/siderolabs/go-cmd/pkg/cmd"
 
 	"github.com/siderolabs/talos/internal/app/machined/pkg/runtime/v1alpha1/bootloader/grub"
+	"github.com/siderolabs/talos/pkg/imager/quirks"
 	"github.com/siderolabs/talos/pkg/imager/utils"
 )
 
@@ -24,6 +25,7 @@ type GRUBOptions struct {
 	KernelPath    string
 	InitramfsPath string
 	Cmdline       string
+	Version       string
 
 	ScratchDir string
 
@@ -59,9 +61,11 @@ func CreateGRUB(printf func(string, ...any), options GRUBOptions) error {
 	}
 
 	if err = tmpl.Execute(&grubCfg, struct {
-		Cmdline string
+		Cmdline        string
+		AddResetOption bool
 	}{
-		Cmdline: options.Cmdline,
+		Cmdline:        options.Cmdline,
+		AddResetOption: quirks.New(options.Version).SupportsResetGRUBOption(),
 	}); err != nil {
 		return err
 	}

pkg/imager/out.go

@@ -153,6 +153,7 @@ func (i *Imager) outISO(ctx context.Context, path string, report *reporter.Repor
 			KernelPath:    i.prof.Input.Kernel.Path,
 			InitramfsPath: i.initramfsPath,
 			Cmdline:       i.cmdline,
+			Version:       i.prof.Version,
 
 			ScratchDir: scratchSpace,
 			OutPath:    path,

pkg/imager/quirks/quirks.go

@@ -0,0 +1,35 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+// Package quirks contains the quirks for Talos image generation.
+package quirks
+
+import "github.com/blang/semver/v4"
+
+// Quirks contains the quirks for Talos image generation.
+type Quirks struct {
+	v *semver.Version
+}
+
+// New returns a new Quirks instance based on Talos version for the image.
+func New(talosVersion string) Quirks {
+	v, err := semver.ParseTolerant(talosVersion) // ignore the error
+	if err != nil {
+		return Quirks{}
+	}
+
+	return Quirks{v: &v}
+}
+
+var minVersionResetOption = semver.MustParse("1.4.0")
+
+// SupportsResetGRUBOption returns true if the Talos version supports the reset option in GRUB menu (image and ISO).
+func (q Quirks) SupportsResetGRUBOption() bool {
+	// if the version doesn't parse, we assume it's latest Talos
+	if q.v == nil {
+		return true
+	}
+
+	return q.v.GTE(minVersionResetOption)
+}

pkg/imager/quirks/quirks_test.go

@@ -0,0 +1,37 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package quirks_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/siderolabs/talos/pkg/imager/quirks"
+)
+
+func TestSupportsResetOption(t *testing.T) {
+	for _, test := range []struct {
+		version string
+
+		expected bool
+	}{
+		{
+			version:  "1.5.0",
+			expected: true,
+		},
+		{
+			expected: true,
+		},
+		{
+			version:  "1.3.7",
+			expected: false,
+		},
+	} {
+		t.Run(test.version, func(t *testing.T) {
+			assert.Equal(t, test.expected, quirks.New(test.version).SupportsResetGRUBOption())
+		})
+	}
+}