check if device contains filesystem before format

internal/virt/agent/agent.go

@@ -28,7 +28,7 @@ type Interface interface { //nolint
 	WriteFile(ctx context.Context, handle int, buf []byte) error
 	SeekFile(ctx context.Context, handle int, offset int, whence int) (position int, eof bool, err error)
 	AppendLine(ctx context.Context, filepath string, p []byte) error
-	Blkid(ctx context.Context, dev string) (string, error)
+	Blkid(ctx context.Context, dev string) (*types.BlkidInfo, error)
 	GetDiskfree(ctx context.Context, mnt string) (*types.Diskfree, error)
 	FSFreezeAll(ctx context.Context) (int, error)
 	FSThawAll(ctx context.Context) (int, error)

internal/virt/agent/blk.go

@@ -5,23 +5,27 @@ import (
 	"regexp"
 
 	"github.com/cockroachdb/errors"
+	"github.com/projecteru2/yavirt/internal/virt/agent/types"
 	"github.com/projecteru2/yavirt/pkg/terrors"
 )
 
-var blkidRegex = regexp.MustCompile(`(?i)uuid="([-a-f0-9]{36})"`)
+var blkidRegex = regexp.MustCompile(`(?i)uuid="([-a-f0-9]{36}).*TYPE="([^"]+)"`)
 
 // Blkid .
-func (a *Agent) Blkid(ctx context.Context, dev string) (string, error) {
+func (a *Agent) Blkid(ctx context.Context, dev string) (*types.BlkidInfo, error) {
 	var st = <-a.ExecOutput(ctx, "blkid", dev)
 	so, _, err := st.Stdio()
 	if err != nil {
-		return "", errors.Wrap(err, "")
+		return nil, errors.Wrap(err, "")
 	}
 
 	var mat = blkidRegex.FindSubmatch(so)
 	if mat == nil {
-		return "", errors.Wrapf(terrors.ErrInvalidValue, "invalid blkid: %s", so)
+		return nil, errors.Wrapf(terrors.ErrInvalidValue, "invalid blkid: %s", so)
 	}
 
-	return string(mat[1]), nil
+	return &types.BlkidInfo{
+		ID:   string(mat[1]),
+		Type: string(mat[2]),
+	}, nil
 }