Writes and verify image

clitools/pkg/controller/osimage/verify_safe.go

@@ -0,0 +1,35 @@
+//go:build !dev
+
+package osimage
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+func CheckTargetSafe(targetPath string, expectedRawSize int64) error {
+
+	if !strings.HasPrefix(targetPath, "/dev/") {
+		return fmt.Errorf("target must be a device path under /dev")
+	}
+
+	st, err := os.Stat(targetPath)
+	if err != nil {
+		return fmt.Errorf("stat target: %w", err)
+	}
+
+	mode := st.Mode()
+	if mode&os.ModeDevice == 0 {
+		return fmt.Errorf("target is not a device")
+	}
+
+	// TODO: Add stronger checks
+	// - EnsureNotMounted(targetPath)
+	// - EnsureNotCurrentRoot(targetPath)
+	// - EnsurePartitionNotWholeDisk(targetPath)
+	// - EnsureCapacity(targetPath, expectedRawSize)
+
+	_ = expectedRawSize
+	return nil
+}