feat: docker compose backup

2026-07-04 17:20:28 +08:00
commit 5c8944fd58
27 changed files with 2070 additions and 0 deletions
@@ -0,0 +1,140 @@
+package backup
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+)
+
+// DirectoryCopier copies a directory tree with optional exclusions.
+type DirectoryCopier struct {
+	Exclude []string
+	Context context.Context // optional; checked during copy
+}
+
+// Copy recursively copies src to dst, skipping paths that match any
+// exclusion pattern (filepath.Match semantics). Skips special files
+// (sockets, FIFOs, devices) that cannot be meaningfully copied.
+func (c *DirectoryCopier) Copy(src, dst string) error {
+	return filepath.WalkDir(src, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if c.Context != nil {
+			select {
+			case <-c.Context.Done():
+				return c.Context.Err()
+			default:
+			}
+		}
+
+		rel, err := filepath.Rel(src, path)
+		if err != nil {
+			return fmt.Errorf("rel(%s, %s): %w", src, path, err)
+		}
+		if rel == "." {
+			return nil
+		}
+
+		for _, pattern := range c.Exclude {
+			matched, err := filepath.Match(pattern, rel)
+			if err != nil {
+				continue
+			}
+			baseMatched, _ := filepath.Match(pattern, d.Name())
+			if matched || baseMatched {
+				if d.IsDir() {
+					return filepath.SkipDir
+				}
+				return nil
+			}
+		}
+
+		target := filepath.Join(dst, rel)
+		if d.IsDir() {
+			return copyDirMetadata(path, target, d)
+		}
+
+		if isSpecial(d) {
+			return nil
+		}
+
+		return copyFile(path, target, d)
+	})
+}
+
+func copyDirMetadata(src, dst string, entry fs.DirEntry) error {
+	info, err := entry.Info()
+	if err != nil {
+		return err
+	}
+	if err := os.MkdirAll(dst, info.Mode()); err != nil {
+		return err
+	}
+	if err := os.Chmod(dst, info.Mode()); err != nil {
+		return err
+	}
+	return os.Chtimes(dst, info.ModTime(), info.ModTime())
+}
+
+// isSpecial returns true if the entry is a socket, FIFO, device, or other
+// non-regular, non-symlink, non-directory file.
+func isSpecial(d fs.DirEntry) bool {
+	if d.Type().IsRegular() || d.Type()&fs.ModeSymlink != 0 {
+		return false
+	}
+	info, err := d.Info()
+	if err != nil {
+		return true // can't stat → skip it
+	}
+	mode := info.Mode()
+	return mode&(os.ModeSocket|os.ModeNamedPipe|os.ModeDevice|os.ModeCharDevice) != 0
+}
+
+func copyFile(src, dst string, entry fs.DirEntry) error {
+	info, err := entry.Info()
+	if err != nil {
+		return err
+	}
+
+	if info.Mode()&os.ModeSymlink != 0 {
+		link, err := os.Readlink(src)
+		if err != nil {
+			return err
+		}
+		_ = os.Remove(dst)
+		return os.Symlink(link, dst)
+	}
+
+	srcFile, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer srcFile.Close()
+
+	if err := os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
+		return err
+	}
+
+	dstFile, err := os.OpenFile(dst, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, info.Mode())
+	if err != nil {
+		return err
+	}
+
+	_, copyErr := io.Copy(dstFile, srcFile)
+	closeErr := dstFile.Close()
+	if copyErr != nil {
+		return copyErr
+	}
+	if closeErr != nil {
+		return closeErr
+	}
+	if err := os.Chmod(dst, info.Mode()); err != nil {
+		return err
+	}
+	return os.Chtimes(dst, info.ModTime(), info.ModTime())
+}