backup.go
| 1 | package database |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "database/sql" |
| 6 | "fmt" |
| 7 | "log/slog" |
| 8 | "os" |
| 9 | "path/filepath" |
| 10 | "sort" |
| 11 | "strings" |
| 12 | "time" |
| 13 | ) |
| 14 | |
| 15 | // Backup schreibt eine konsistente Kopie der laufenden Datenbank (VACUUM INTO). |
| 16 | // Ein einfaches cp der .db-Datei reicht im WAL-Modus NICHT – Daten liegen ggf. noch in -wal. |
| 17 | func Backup(ctx context.Context, db *sql.DB, dir string) (string, error) { |
| 18 | if err := os.MkdirAll(dir, 0o700); err != nil { |
| 19 | return "", err |
| 20 | } |
| 21 | name := filepath.Join(dir, "physiobase-"+time.Now().Format("2006-01-02_150405")+".db") |
| 22 | if _, err := db.ExecContext(ctx, `VACUUM INTO ?`, name); err != nil { |
| 23 | os.Remove(name) |
| 24 | return "", fmt.Errorf("backup: %w", err) |
| 25 | } |
| 26 | if err := os.Chmod(name, 0o600); err != nil { |
| 27 | return name, fmt.Errorf("backup rechte: %w", err) |
| 28 | } |
| 29 | return name, nil |
| 30 | } |
| 31 | |
| 32 | // Prune behält die neuesten keep Backups. |
| 33 | func Prune(dir string, keep int) error { |
| 34 | files, err := filepath.Glob(filepath.Join(dir, "physiobase-*.db")) |
| 35 | if err != nil { |
| 36 | return err |
| 37 | } |
| 38 | sort.Strings(files) // Zeitstempel im Namen → chronologisch |
| 39 | for i := 0; i < len(files)-keep; i++ { |
| 40 | if strings.HasPrefix(filepath.Base(files[i]), "physiobase-") { |
| 41 | os.Remove(files[i]) |
| 42 | } |
| 43 | } |
| 44 | return nil |
| 45 | } |
| 46 | |
| 47 | // RunBackups: sofort beim Start, danach alle 24 h, bis ctx endet. |
| 48 | func RunBackups(ctx context.Context, db *sql.DB, dir string, keep int, log *slog.Logger) { |
| 49 | if keep <= 0 { |
| 50 | log.Info("automatische backups deaktiviert") |
| 51 | return |
| 52 | } |
| 53 | run := func() { |
| 54 | name, err := Backup(ctx, db, dir) |
| 55 | if err != nil { |
| 56 | log.Error("backup fehlgeschlagen", "err", err) |
| 57 | return |
| 58 | } |
| 59 | if err := Prune(dir, keep); err != nil { |
| 60 | log.Warn("alte backups nicht gelöscht", "err", err) |
| 61 | } |
| 62 | log.Info("backup erstellt", "datei", name) |
| 63 | } |
| 64 | run() |
| 65 | t := time.NewTicker(24 * time.Hour) |
| 66 | defer t.Stop() |
| 67 | for { |
| 68 | select { |
| 69 | case <-ctx.Done(): |
| 70 | return |
| 71 | case <-t.C: |
| 72 | run() |
| 73 | } |
| 74 | } |
| 75 | } |
| 76 |