Bring GHW clone and partition type into sdk (#492)

ghw/ghw.go

@@ -0,0 +1,326 @@
+package ghw
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/kairos-io/kairos-sdk/types"
+)
+
+const (
+	sectorSize = 512
+	UNKNOWN    = "unknown"
+)
+
+type Disk struct {
+	Name       string              `json:"name,omitempty" yaml:"name,omitempty"`
+	SizeBytes  uint64              `json:"size_bytes,omitempty" yaml:"size_bytes,omitempty"`
+	UUID       string              `json:"uuid,omitempty" yaml:"uuid,omitempty"`
+	Partitions types.PartitionList `json:"partitions,omitempty" yaml:"partitions,omitempty"`
+}
+
+type Paths struct {
+	SysBlock    string
+	RunUdevData string
+	ProcMounts  string
+}
+
+func NewPaths(withOptionalPrefix string) *Paths {
+	p := &Paths{
+		SysBlock:    "/sys/block/",
+		RunUdevData: "/run/udev/data",
+		ProcMounts:  "/proc/mounts",
+	}
+	if withOptionalPrefix != "" {
+		withOptionalPrefix = strings.TrimSuffix(withOptionalPrefix, "/")
+		p.SysBlock = fmt.Sprintf("%s%s", withOptionalPrefix, p.SysBlock)
+		p.RunUdevData = fmt.Sprintf("%s%s", withOptionalPrefix, p.RunUdevData)
+		p.ProcMounts = fmt.Sprintf("%s%s", withOptionalPrefix, p.ProcMounts)
+	}
+	return p
+}
+
+func GetDisks(paths *Paths, logger *types.KairosLogger) []*Disk {
+	if logger == nil {
+		newLogger := types.NewKairosLogger("ghw", "info", false)
+		logger = &newLogger
+	}
+	disks := make([]*Disk, 0)
+	logger.Logger.Debug().Str("path", paths.SysBlock).Msg("Scanning for disks")
+	files, err := os.ReadDir(paths.SysBlock)
+	if err != nil {
+		return nil
+	}
+	for _, file := range files {
+		logger.Logger.Debug().Str("file", file.Name()).Msg("Reading file")
+		dname := file.Name()
+		size := diskSizeBytes(paths, dname, logger)
+
+		if strings.HasPrefix(dname, "loop") && size == 0 {
+			// We don't care about unused loop devices...
+			continue
+		}
+		d := &Disk{
+			Name:      dname,
+			SizeBytes: size,
+			UUID:      diskUUID(paths, dname, "", logger),
+		}
+
+		parts := diskPartitions(paths, dname, logger)
+		d.Partitions = parts
+
+		disks = append(disks, d)
+	}
+
+	return disks
+}
+
+func diskSizeBytes(paths *Paths, disk string, logger *types.KairosLogger) uint64 {
+	// We can find the number of 512-byte sectors by examining the contents of
+	// /sys/block/$DEVICE/size and calculate the physical bytes accordingly.
+	path := filepath.Join(paths.SysBlock, disk, "size")
+	logger.Logger.Debug().Str("path", path).Msg("Reading disk size")
+	contents, err := os.ReadFile(path)
+	if err != nil {
+		logger.Logger.Error().Str("path", path).Err(err).Msg("Failed to read file")
+		return 0
+	}
+	size, err := strconv.ParseUint(strings.TrimSpace(string(contents)), 10, 64)
+	if err != nil {
+		logger.Logger.Error().Str("path", path).Err(err).Str("content", string(contents)).Msg("Failed to parse size")
+		return 0
+	}
+	logger.Logger.Trace().Uint64("size", size*sectorSize).Msg("Got disk size")
+	return size * sectorSize
+}
+
+// diskPartitions takes the name of a disk (note: *not* the path of the disk,
+// but just the name. In other words, "sda", not "/dev/sda" and "nvme0n1" not
+// "/dev/nvme0n1") and returns a slice of pointers to Partition structs
+// representing the partitions in that disk
+func diskPartitions(paths *Paths, disk string, logger *types.KairosLogger) types.PartitionList {
+	out := make(types.PartitionList, 0)
+	path := filepath.Join(paths.SysBlock, disk)
+	logger.Logger.Debug().Str("file", path).Msg("Reading disk file")
+	files, err := os.ReadDir(path)
+	if err != nil {
+		logger.Logger.Error().Err(err).Msg("failed to read disk partitions")
+		return out
+	}
+	for _, file := range files {
+		fname := file.Name()
+		if !strings.HasPrefix(fname, disk) {
+			continue
+		}
+		logger.Logger.Debug().Str("file", fname).Msg("Reading partition file")
+		size := partitionSizeBytes(paths, disk, fname, logger)
+		mp, pt := partitionInfo(paths, fname, logger)
+		du := diskPartUUID(paths, disk, fname, logger)
+		if pt == "" {
+			pt = diskPartTypeUdev(paths, disk, fname, logger)
+		}
+		fsLabel := diskFSLabel(paths, disk, fname, logger)
+		p := &types.Partition{
+			Name:            fname,
+			Size:            uint(size / (1024 * 1024)),
+			MountPoint:      mp,
+			UUID:            du,
+			FilesystemLabel: fsLabel,
+			FS:              pt,
+			Path:            filepath.Join("/dev", fname),
+			Disk:            filepath.Join("/dev", disk),
+		}
+		out = append(out, p)
+	}
+	return out
+}
+
+func partitionSizeBytes(paths *Paths, disk string, part string, logger *types.KairosLogger) uint64 {
+	path := filepath.Join(paths.SysBlock, disk, part, "size")
+	logger.Logger.Debug().Str("file", path).Msg("Reading size file")
+	contents, err := os.ReadFile(path)
+	if err != nil {
+		logger.Logger.Error().Str("file", path).Err(err).Msg("failed to read disk partition size")
+		return 0
+	}
+	size, err := strconv.ParseUint(strings.TrimSpace(string(contents)), 10, 64)
+	if err != nil {
+		logger.Logger.Error().Str("contents", string(contents)).Err(err).Msg("failed to parse disk partition size")
+		return 0
+	}
+	logger.Logger.Trace().Str("disk", disk).Str("partition", part).Uint64("size", size*sectorSize).Msg("Got partition size")
+	return size * sectorSize
+}
+
+func partitionInfo(paths *Paths, part string, logger *types.KairosLogger) (string, string) {
+	// Allow calling PartitionInfo with either the full partition name
+	// "/dev/sda1" or just "sda1"
+	if !strings.HasPrefix(part, "/dev") {
+		part = "/dev/" + part
+	}
+
+	// mount entries for mounted partitions look like this:
+	// /dev/sda6 / ext4 rw,relatime,errors=remount-ro,data=ordered 0 0
+	var r io.ReadCloser
+	logger.Logger.Debug().Str("file", paths.ProcMounts).Msg("Reading mounts file")
+	r, err := os.Open(paths.ProcMounts)
+	if err != nil {
+		logger.Logger.Error().Str("file", paths.ProcMounts).Err(err).Msg("failed to open mounts")
+		return "", ""
+	}
+	defer r.Close()
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		line := scanner.Text()
+		logger.Logger.Debug().Str("line", line).Msg("Parsing mount info")
+		entry := parseMountEntry(line, logger)
+		if entry == nil || entry.Partition != part {
+			continue
+		}
+
+		return entry.Mountpoint, entry.FilesystemType
+	}
+	return "", ""
+}
+
+type mountEntry struct {
+	Partition      string
+	Mountpoint     string
+	FilesystemType string
+}
+
+func parseMountEntry(line string, logger *types.KairosLogger) *mountEntry {
+	// mount entries for mounted partitions look like this:
+	// /dev/sda6 / ext4 rw,relatime,errors=remount-ro,data=ordered 0 0
+	if line[0] != '/' {
+		return nil
+	}
+	fields := strings.Fields(line)
+
+	if len(fields) < 4 {
+		logger.Logger.Debug().Interface("fields", fields).Msg("Mount line has less than 4 fields")
+		return nil
+	}
+
+	// We do some special parsing of the mountpoint, which may contain space,
+	// tab and newline characters, encoded into the mount entry line using their
+	// octal-to-string representations. From the GNU mtab man pages:
+	//
+	//   "Therefore these characters are encoded in the files and the getmntent
+	//   function takes care of the decoding while reading the entries back in.
+	//   '\040' is used to encode a space character, '\011' to encode a tab
+	//   character, '\012' to encode a newline character, and '\\' to encode a
+	//   backslash."
+	mp := fields[1]
+	r := strings.NewReplacer(
+		"\\011", "\t", "\\012", "\n", "\\040", " ", "\\\\", "\\",
+	)
+	mp = r.Replace(mp)
+
+	res := &mountEntry{
+		Partition:      fields[0],
+		Mountpoint:     mp,
+		FilesystemType: fields[2],
+	}
+	return res
+}
+
+func diskUUID(paths *Paths, disk string, partition string, logger *types.KairosLogger) string {
+	info, err := udevInfoPartition(paths, disk, partition, logger)
+	logger.Logger.Trace().Interface("info", info).Msg("Disk UUID")
+	if err != nil {
+		logger.Logger.Error().Str("disk", disk).Str("partition", partition).Interface("info", info).Err(err).Msg("failed to read disk UUID")
+		return UNKNOWN
+	}
+
+	if pType, ok := info["ID_PART_TABLE_UUID"]; ok {
+		logger.Logger.Trace().Str("disk", disk).Str("partition", partition).Str("uuid", pType).Msg("Got disk uuid")
+		return pType
+	}
+
+	return UNKNOWN
+}
+
+func diskPartUUID(paths *Paths, disk string, partition string, logger *types.KairosLogger) string {
+	info, err := udevInfoPartition(paths, disk, partition, logger)
+	logger.Logger.Trace().Interface("info", info).Msg("Disk Part UUID")
+	if err != nil {
+		logger.Logger.Error().Str("disk", disk).Str("partition", partition).Interface("info", info).Err(err).Msg("Disk Part UUID")
+		return UNKNOWN
+	}
+
+	if pType, ok := info["ID_PART_ENTRY_UUID"]; ok {
+		logger.Logger.Trace().Str("disk", disk).Str("partition", partition).Str("uuid", pType).Msg("Got partition uuid")
+		return pType
+	}
+	return UNKNOWN
+}
+
+// diskPartTypeUdev gets the partition type from the udev database directly and its only used as fallback when
+// the partition is not mounted, so we cannot get the type from paths.ProcMounts from the partitionInfo function
+func diskPartTypeUdev(paths *Paths, disk string, partition string, logger *types.KairosLogger) string {
+	info, err := udevInfoPartition(paths, disk, partition, logger)
+	logger.Logger.Trace().Interface("info", info).Msg("Disk Part Type")
+	if err != nil {
+		logger.Logger.Error().Str("disk", disk).Str("partition", partition).Interface("info", info).Err(err).Msg("Disk Part Type")
+		return UNKNOWN
+	}
+
+	if pType, ok := info["ID_FS_TYPE"]; ok {
+		logger.Logger.Trace().Str("disk", disk).Str("partition", partition).Str("FS", pType).Msg("Got partition fs type")
+		return pType
+	}
+	return UNKNOWN
+}
+
+func diskFSLabel(paths *Paths, disk string, partition string, logger *types.KairosLogger) string {
+	info, err := udevInfoPartition(paths, disk, partition, logger)
+	logger.Logger.Trace().Interface("info", info).Msg("Disk FS label")
+	if err != nil {
+		logger.Logger.Error().Str("disk", disk).Str("partition", partition).Interface("info", info).Err(err).Msg("Disk FS label")
+		return UNKNOWN
+	}
+
+	if label, ok := info["ID_FS_LABEL"]; ok {
+		logger.Logger.Trace().Str("disk", disk).Str("partition", partition).Str("uuid", label).Msg("Got partition label")
+		return label
+	}
+	return UNKNOWN
+}
+
+func udevInfoPartition(paths *Paths, disk string, partition string, logger *types.KairosLogger) (map[string]string, error) {
+	// Get device major:minor numbers
+	devNo, err := os.ReadFile(filepath.Join(paths.SysBlock, disk, partition, "dev"))
+	if err != nil {
+		logger.Logger.Error().Err(err).Str("path", filepath.Join(paths.SysBlock, disk, partition, "dev")).Msg("failed to read udev info")
+		return nil, err
+	}
+	return UdevInfo(paths, string(devNo), logger)
+}
+
+// UdevInfo will return information on udev database about a device number
+func UdevInfo(paths *Paths, devNo string, logger *types.KairosLogger) (map[string]string, error) {
+	// Look up block device in udev runtime database
+	udevID := "b" + strings.TrimSpace(devNo)
+	udevBytes, err := os.ReadFile(filepath.Join(paths.RunUdevData, udevID))
+	if err != nil {
+		logger.Logger.Error().Err(err).Str("path", filepath.Join(paths.RunUdevData, udevID)).Msg("failed to read udev info for device")
+		return nil, err
+	}
+
+	udevInfo := make(map[string]string)
+	for _, udevLine := range strings.Split(string(udevBytes), "\n") {
+		if strings.HasPrefix(udevLine, "E:") {
+			if s := strings.SplitN(udevLine[2:], "=", 2); len(s) == 2 {
+				udevInfo[s[0]] = s[1]
+			}
+		}
+	}
+	return udevInfo, nil
+}