Use lsblk to detect partitions

like we did here:

https://github.com/kairos-io/kairos-sdk/pull/28/files

because ghw doesn't play well with lvm

Signed-off-by: Dimitris Karakasilis <dimitris@karakasilis.me>

pkg/utils/getpartitions.go

@@ -17,6 +17,7 @@ limitations under the License.
 package utils
 
 import (
+	"encoding/json"
 	"fmt"
 	"path/filepath"
 	"strings"
@@ -30,35 +31,80 @@ import (
 	v1 "github.com/kairos-io/kairos/v2/pkg/types/v1"
 )
 
-// ghwPartitionToInternalPartition transforms a block.Partition from ghw lib to our v1.Partition type
-func ghwPartitionToInternalPartition(partition *block.Partition) *v1.Partition {
-	return &v1.Partition{
-		FilesystemLabel: partition.FilesystemLabel,
-		Size:            uint(partition.SizeBytes / (1024 * 1024)), // Converts B to MB
-		Name:            partition.Name,
-		FS:              partition.Type,
-		Flags:           nil,
-		MountPoint:      partition.MountPoint,
-		Path:            filepath.Join("/dev", partition.Name),
-		Disk:            filepath.Join("/dev", partition.Disk.Name),
-	}
+type PartInfo struct {
+	Name       string `json:"name,omitempty"`
+	PkName     string `json:"pkname,omitempty"`
+	Path       string `json:"path,omitempty"`
+	Mountpoint string `json:"mountpoint,omitempty"`
+	FsType     string `json:"fstype,omitempty"`
+	Size       uint   `json:"size,omitempty"`
+	Label      string `json:"label,omitempty"`
+	RO         bool   `json:"ro,omitempty"`
+}
+
+// Lsblk is the struct to marshal the output of lsblk
+type Lsblk struct {
+	BlockDevices []PartInfo `json:"blockdevices,omitempty"`
 }
 
 // GetAllPartitions returns all partitions in the system for all disks
-func GetAllPartitions() (v1.PartitionList, error) {
-	var parts []*v1.Partition
-	blockDevices, err := block.New(ghw.WithDisableTools(), ghw.WithDisableWarnings())
+func GetAllPartitions(runner v1.Runner) (v1.PartitionList, error) {
+	parts := v1.PartitionList{}
+
+	// --list : show each partition only once
+	// --bytes: don't show sizes in human readable format but rather number of bytes
+	out, err := runner.Run("lsblk", "--list", "--bytes",
+		"/dev/disk/by-path/*", "-o", "NAME,PKNAME,PATH,FSTYPE,MOUNTPOINT,SIZE,RO,LABEL", "-J")
 	if err != nil {
-		return nil, err
+		return parts, fmt.Errorf("lsblk failed with: %w\nOutput: %s", err, string(out))
 	}
-	for _, d := range blockDevices.Disks {
-		for _, part := range d.Partitions {
-			parts = append(parts, ghwPartitionToInternalPartition(part))
+
+	return PartitionsFromLsblk(string(out))
+}
+
+func PartitionsFromLsblk(lsblkOutput string) (v1.PartitionList, error) {
+	lsblk := &Lsblk{}
+	parts := v1.PartitionList{}
+	parentsLookup := map[string]string{}
+
+	err := json.Unmarshal([]byte(lsblkOutput), lsblk)
+	if err != nil {
+		return parts, err
+	}
+
+	for _, p := range lsblk.BlockDevices {
+		part := v1.Partition{}
+		parentsLookup[p.Name] = p.PkName
+		part.Name = p.Name
+		part.FilesystemLabel = p.Label
+		part.Size = p.Size / (1024 * 1024) // Converts B to MB
+		part.Flags = nil
+		part.MountPoint = p.Mountpoint
+		part.FS = p.FsType
+		part.Path = p.Path
+		parts = append(parts, &part)
+	}
+
+	// Add `Disk` field to all partitions
+	for _, p := range parts {
+		disk := findDisk(parentsLookup, p.Name)
+		if disk != "" {
+			p.Disk = filepath.Join("/dev", disk)
 		}
 	}
+
 	return parts, nil
 }
 
+func findDisk(parentsLookup map[string]string, pName string) string {
+	parent, hasParent := parentsLookup[pName]
+	if !hasParent || parent == "" {
+		return pName // A disk's disk is itself
+	}
+
+	return findDisk(parentsLookup, parent)
+}
+
 // GetPartitionFS gets the FS of a partition given
 func GetPartitionFS(partition string) (string, error) {
 	// We want to have the device always prefixed with a /dev