debug

Author: ptrus

cmd/rofl/build/artifacts.go

@@ -14,6 +14,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"sort"
 	"strings"
 	"time"
 
@@ -316,6 +317,12 @@ func createSquashFs(buildEnv env.ExecEnv, fn, dir string) (int64, error) {
 	}
 
 	// Create reproducible tar archive.
+	if os.Getenv("ROFL_DEBUG_ROOTFS_HASH") != "" {
+		if err := debugRootfsHashes(dir); err != nil {
+			return 0, fmt.Errorf("failed to compute rootfs debug hashes: %w", err)
+		}
+	}
+
 	tarPath := fn + ".tar"
 	tarPathEnv, err := buildEnv.PathToEnv(tarPath)
 	if err != nil {
@@ -417,6 +424,69 @@ func createSquashFs(buildEnv env.ExecEnv, fn, dir string) (int64, error) {
 	return fi.Size(), nil
 }
 
+// debugRootfsHashes prints deterministic SHA256 hashes for all files in dir to help diagnose
+// cross-host differences. Controlled via ROFL_DEBUG_ROOTFS_HASH env var.
+func debugRootfsHashes(dir string) error {
+	type entry struct {
+		path string
+		hash string
+	}
+	var entries []entry
+
+	err := filepath.WalkDir(dir, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if d.IsDir() {
+			return nil
+		}
+		rel, err := filepath.Rel(dir, path)
+		if err != nil {
+			return err
+		}
+
+		fi, err := os.Lstat(path)
+		if err != nil {
+			return err
+		}
+
+		switch {
+		case fi.Mode()&os.ModeSymlink != 0:
+			target, err := os.Readlink(path)
+			if err != nil {
+				return err
+			}
+			entries = append(entries, entry{path: rel, hash: "symlink->" + target})
+		default:
+			f, err := os.Open(path)
+			if err != nil {
+				return err
+			}
+			h := sha256.New()
+			if _, err = io.Copy(h, f); err != nil {
+				f.Close()
+				return err
+			}
+			f.Close()
+			entries = append(entries, entry{path: rel, hash: fmt.Sprintf("%x", h.Sum(nil))})
+		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	sort.Slice(entries, func(i, j int) bool {
+		return entries[i].path < entries[j].path
+	})
+
+	fmt.Println("Rootfs file hashes (debug):")
+	for _, e := range entries {
+		fmt.Printf("  %s %s\n", e.hash, e.path)
+	}
+	return nil
+}
+
 // sha256File computes a SHA-256 digest of the file with the given filename and returns a
 // hex-encoded hash.
 func sha256File(fn string) (string, error) {