feat: Introduce support for erofs initrds

.goreleaser-stable.yaml

@@ -74,6 +74,7 @@ nfpms:
     recommends:
       - bison
       - build-essential
+      - erofs-utils
       - flex
       - git
       - libncurses-dev

.goreleaser-staging.yaml

@@ -62,6 +62,7 @@ nfpms:
     recommends:
       - bison
       - build-essential
+      - erofs-utils
       - flex
       - git
       - libncurses-dev

initrd/directory.go

@@ -77,6 +77,10 @@ func (initrd *directory) Build(ctx context.Context) (string, error) {
 		return "", fmt.Errorf("could not create output directory: %w", err)
 	}
 
+	if initrd.opts.fsType == FsTypeErofs {
+		return initrd.opts.output, convertToErofs(ctx, initrd.opts.output, initrd.path, false, false)
+	}
+
 	f, err := os.OpenFile(initrd.opts.output, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o644)
 	if err != nil {
 		return "", fmt.Errorf("could not open initramfs file: %w", err)

initrd/dockerfile.go

@@ -225,12 +225,6 @@ func (initrd *dockerfile) Build(ctx context.Context) (string, error) {
 		initrd.opts.output = fi.Name()
 	}
 
-	outputDir, err := os.MkdirTemp("", "")
-	if err != nil {
-		return "", fmt.Errorf("could not make temporary directory: %w", err)
-	}
-	defer os.RemoveAll(outputDir)
-
 	tarOutput, err := os.CreateTemp("", "")
 	if err != nil {
 		return "", fmt.Errorf("could not make temporary file: %w", err)
@@ -516,6 +510,14 @@ func (initrd *dockerfile) Build(ctx context.Context) (string, error) {
 		return "", fmt.Errorf("could not create output directory: %w", err)
 	}
 
+	if initrd.opts.fsType == FsTypeErofs {
+		err := tarOutput.Close()
+		if err != nil && !strings.Contains(err.Error(), "file already closed") {
+			return "", fmt.Errorf("could not close tarball: %w", err)
+		}
+		return initrd.opts.output, convertToErofs(ctx, initrd.opts.output, tarOutput.Name(), true, false)
+	}
+
 	cpioFile, err := os.OpenFile(initrd.opts.output, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o644)
 	if err != nil {
 		return "", fmt.Errorf("could not open initramfs file: %w", err)

initrd/file.go

@@ -60,7 +60,25 @@ func (initrd *file) Name() string {
 }
 
 // Build implements Initrd.
-func (initrd *file) Build(_ context.Context) (string, error) {
+func (initrd *file) Build(ctx context.Context) (string, error) {
+	if initrd.opts.fsType == FsTypeErofs {
+		isCpio, err := isCpioFile(initrd.path)
+		if err != nil {
+			return "", fmt.Errorf("could not determine if file is a CPIO archive: %w", err)
+		}
+
+		if isCpio {
+			return "", fmt.Errorf("CPIO-to-EROFS conversion currently not supported. Use 'bsdcpio' or 'cpio' to unpack it first to a directory")
+		}
+
+		isTar, isGz, err := isTarGzFile(initrd.path)
+		if err != nil {
+			return "", fmt.Errorf("could not determine if file is a tar/gz archive: %w", err)
+		}
+
+		return initrd.opts.output, convertToErofs(ctx, initrd.opts.output, initrd.path, isTar, isGz)
+	}
+
 	return initrd.path, nil
 }
 

initrd/ociimage.go

@@ -177,6 +177,10 @@ func (initrd *ociimage) Build(ctx context.Context) (string, error) {
 		return "", fmt.Errorf("could not create output directory: %w", err)
 	}
 
+	if initrd.opts.fsType == FsTypeErofs {
+		return initrd.opts.output, convertToErofs(ctx, initrd.opts.output, ociTarballFile, true, false)
+	}
+
 	f, err := os.OpenFile(initrd.opts.output, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o644)
 	if err != nil {
 		return "", fmt.Errorf("could not open initramfs file: %w", err)

initrd/options.go

@@ -4,29 +4,68 @@
 // You may not use this file except in compliance with the License.
 package initrd
 
+import "fmt"
+
 type InitrdOptions struct {
+	arch     string
+	cacheDir string
 	compress bool
 	output   string
-	cacheDir string
-	arch     string
+	fsType   FsType
 	workdir  string
 }
 
 type InitrdOption func(*InitrdOptions) error
 
-// WithCompression sets the compression of the resulting CPIO archive file.
-func WithCompression(compress bool) InitrdOption {
+type FsType string
+
+const (
+	FsTypeCpio    = FsType("cpio")
+	FsTypeErofs   = FsType("erofs")
+	FsTypeUnknown = FsType("unknown")
+)
+
+var _ fmt.Stringer = (*FsType)(nil)
+
+// String implements fmt.Stringer
+func (fsType FsType) String() string {
+	return string(fsType)
+}
+
+// FsTypes returns the list of possible fsTypes.
+func FsTypes() []FsType {
+	return []FsType{
+		FsTypeCpio,
+		FsTypeErofs,
+	}
+}
+
+// FsTypeNames returns the string representation of all possible
+// fsType implementations.
+func FsTypeNames() []string {
+	types := []string{}
+	for _, name := range FsTypes() {
+		types = append(types, name.String())
+	}
+
+	return types
+}
+
+// WithArchitecture sets the architecture of the file contents of binaries in
+// the initramfs.  Files may not always be architecture specific, this option
+// simply indicates the target architecture if any binaries are compiled by the
+// implementing initrd builder.
+func WithArchitecture(arch string) InitrdOption {
 	return func(opts *InitrdOptions) error {
-		opts.compress = compress
+		opts.arch = arch
 		return nil
 	}
 }
 
-// WithOutput sets the location of the output location of the resulting CPIO
-// archive file.
-func WithOutput(output string) InitrdOption {
+// WithCompression sets the compression of the resulting CPIO archive file.
+func WithCompression(compress bool) InitrdOption {
 	return func(opts *InitrdOptions) error {
-		opts.output = output
+		opts.compress = compress
 		return nil
 	}
 }
@@ -41,13 +80,19 @@ func WithCacheDir(dir string) InitrdOption {
 	}
 }
 
-// WithArchitecture sets the architecture of the file contents of binaries in
-// the initramfs.  Files may not always be architecture specific, this option
-// simply indicates the target architecture if any binaries are compiled by the
-// implementing initrd builder.
-func WithArchitecture(arch string) InitrdOption {
+// WithOutput sets the location of the output location of the resulting CPIO
+// archive file.
+func WithOutput(output string) InitrdOption {
 	return func(opts *InitrdOptions) error {
-		opts.arch = arch
+		opts.output = output
+		return nil
+	}
+}
+
+// WithType sets the filesystem type of the resulting CPIO archive file.
+func WithType(fsType FsType) InitrdOption {
+	return func(opts *InitrdOptions) error {
+		opts.fsType = fsType
 		return nil
 	}
 }

initrd/utils.go

@@ -5,12 +5,18 @@
 package initrd
 
 import (
+	"archive/tar"
 	"compress/gzip"
+	"context"
 	"fmt"
 	"io"
 	"os"
+	"os/exec"
+	"path/filepath"
 
+	"github.com/sirupsen/logrus"
 	"kraftkit.sh/cpio"
+	"kraftkit.sh/log"
 )
 
 func compressFiles(output string, writer *cpio.Writer, reader *os.File) error {
@@ -55,3 +61,85 @@ func compressFiles(output string, writer *cpio.Writer, reader *os.File) error {
 
 	return nil
 }
+
+func convertToErofs(ctx context.Context, output string, source string, isTar, isGz bool) error {
+	if output == "" {
+		return fmt.Errorf("output path is required")
+	}
+
+	if err := os.MkdirAll(filepath.Dir(output), 0o755); err != nil {
+		return fmt.Errorf("could not create output directory: %w", err)
+	}
+
+	_, err := exec.LookPath("mkfs.erofs")
+	if err != nil {
+		return fmt.Errorf("could not find 'mkfs.erofs', try installing 'erofs-utils': %w", err)
+	}
+
+	args := []string{
+		"--all-root",
+		"-d2",
+		"-E", "noinline_data",
+	}
+
+	if isTar {
+		args = append(args, "--tar="+source)
+	}
+
+	if isGz {
+		args = append(args, "--gzip")
+	}
+
+	args = append(args, output, source)
+
+	// Output is a target file
+	// Source is an input directory, tar archive, or erofs file
+	cmd := exec.Command("mkfs.erofs", args...)
+	cmd.Env = os.Environ()
+	cmd.Stderr = log.G(ctx).WriterLevel(logrus.WarnLevel)
+	cmd.Stdout = log.G(ctx).WriterLevel(logrus.DebugLevel)
+	return cmd.Run()
+}
+
+func isCpioFile(initrd string) (bool, error) {
+	fi, err := os.Open(initrd)
+	if err != nil {
+		return false, fmt.Errorf("could not open file: %w", err)
+	}
+	defer fi.Close()
+
+	reader := cpio.NewReader(fi)
+
+	_, _, err = reader.Next()
+	if err != nil {
+		return false, nil
+	}
+
+	return true, nil
+}
+
+func isTarGzFile(initrd string) (isTar bool, isGz bool, err error) {
+	file, err := os.Open(initrd)
+	if err != nil {
+		return false, false, fmt.Errorf("could not open file: %w", err)
+	}
+	defer file.Close()
+
+	gzReader, err := gzip.NewReader(file)
+	if err == nil {
+		defer gzReader.Close()
+		isGz = true
+	}
+
+	var tarReader *tar.Reader
+	if isGz {
+		tarReader = tar.NewReader(gzReader)
+	} else {
+		tarReader = tar.NewReader(file)
+	}
+	_, err = tarReader.Next()
+	if err == nil || err == tar.ErrHeader {
+		isTar = true
+	}
+	return
+}

internal/cli/kraft/build/build.go

@@ -18,6 +18,7 @@ import (
 	"github.com/spf13/cobra"
 
 	"kraftkit.sh/cmdfactory"
+	"kraftkit.sh/initrd"
 	"kraftkit.sh/internal/cli/kraft/utils"
 	"kraftkit.sh/internal/fancymap"
 	"kraftkit.sh/iostreams"
@@ -50,6 +51,7 @@ type BuildOptions struct {
 	PrintStats   bool            `long:"print-stats" usage:"Print build statistics"`
 	Project      app.Application `noattribute:"true"`
 	Rootfs       string          `long:"rootfs" usage:"Specify a path to use as root file system (can be volume or initramfs)"`
+	RootfsType   initrd.FsType   `noattribute:"true"`
 	SaveBuildLog string          `long:"build-log" usage:"Use the specified file to save the output from the build"`
 	Target       *target.Target  `noattribute:"true"`
 	TargetName   string          `long:"target" short:"t" usage:"Build a particular known target"`
@@ -107,7 +109,7 @@ func Build(ctx context.Context, opts *BuildOptions, args ...string) error {
 		return fmt.Errorf("could not complete build: %w", err)
 	}
 
-	if opts.Rootfs, _, _, err = utils.BuildRootfs(ctx, opts.Workdir, opts.Rootfs, false, (*opts.Target).Architecture().String()); err != nil {
+	if opts.Rootfs, _, _, err = utils.BuildRootfs(ctx, opts.Workdir, opts.Rootfs, false, (*opts.Target).Architecture().String(), opts.RootfsType); err != nil {
 		return err
 	}
 
@@ -169,6 +171,15 @@ func NewCmd() *cobra.Command {
 		panic(err)
 	}
 
+	cmd.Flags().Var(
+		cmdfactory.NewEnumFlag[initrd.FsType](
+			initrd.FsTypes(),
+			initrd.FsTypeCpio,
+		),
+		"rootfs-type",
+		"Set the type of the format of the rootfs (cpio/erofs)",
+	)
+
 	return cmd
 }
 

internal/cli/kraft/cloud/deploy/deploy.go

@@ -21,6 +21,7 @@ import (
 
 	"kraftkit.sh/cmdfactory"
 	"kraftkit.sh/config"
+	"kraftkit.sh/initrd"
 	"kraftkit.sh/internal/cli/kraft/cloud/instance/create"
 	"kraftkit.sh/internal/cli/kraft/cloud/instance/logs"
 	"kraftkit.sh/internal/cli/kraft/cloud/utils"
@@ -68,6 +69,7 @@ type DeployOptions struct {
 	RolloutQualifier    create.RolloutQualifier        `noattribute:"true"`
 	RolloutWait         time.Duration                  `local:"true" long:"rollout-wait" usage:"Time to wait before performing rolling out action (ms/s/m/h)" default:"10s"`
 	Rootfs              string                         `local:"true" long:"rootfs" usage:"Specify a path to use as root filesystem"`
+	RootfsType          initrd.FsType                  `noattribute:"true"`
 	Runtime             string                         `local:"true" long:"runtime" usage:"Set an alternative project runtime"`
 	SaveBuildLog        string                         `long:"build-log" usage:"Use the specified file to save the output from the build"`
 	ScaleToZero         *kcinstances.ScaleToZeroPolicy `noattribute:"true"`
@@ -162,6 +164,15 @@ func NewCmd() *cobra.Command {
 		"When a package of the same name exists, use this strategy when applying targets.",
 	)
 
+	cmd.Flags().Var(
+		cmdfactory.NewEnumFlag[initrd.FsType](
+			initrd.FsTypes(),
+			initrd.FsTypeCpio,
+		),
+		"rootfs-type",
+		"Set the type of the format of the rootfs (cpio/erofs)",
+	)
+
 	return cmd
 }
 
@@ -176,6 +187,10 @@ func (opts *DeployOptions) Pre(cmd *cobra.Command, _ []string) error {
 	opts.RolloutQualifier = create.RolloutQualifier(cmd.Flag("rollout-qualifier").Value.String())
 	opts.Strategy = packmanager.MergeStrategy(cmd.Flag("strategy").Value.String())
 
+	if cmd.Flag("rootfs-type").Changed {
+		opts.RootfsType = initrd.FsType(cmd.Flag("rootfs-type").Value.String())
+	}
+
 	if cmd.Flag("scale-to-zero").Changed {
 		s20v := kcinstances.ScaleToZeroPolicy(cmd.Flag("scale-to-zero").Value.String())
 		opts.ScaleToZero = &s20v

internal/cli/kraft/cloud/deploy/deployer_kraftfile_runtime.go

@@ -108,6 +108,7 @@ func (deployer *deployerKraftfileRuntime) Deploy(ctx context.Context, opts *Depl
 		Project:      opts.Project,
 		Push:         true,
 		Rootfs:       opts.Rootfs,
+		RootfsType:   opts.RootfsType,
 		Runtime:      opts.Runtime,
 		Strategy:     opts.Strategy,
 		Workdir:      opts.Workdir,