Add SudoPassCmd configuration for more convenience

examples/json.cfg

@@ -1,20 +1,23 @@
-[
-  {
-    "Name": "BtrFS Backup Example",
-    "UUID": "12345678-1234-5678-1234-567812345678",
-    "DevicePassCmd": "echo device-password",
-    "BackupRepositoryFolder": "ButterBackupRepo",
-    "Compression": "zstd:3",
-    "Folders": { "/tmp": "temp-files" },
-    "Files": [],
-    "FilesDest": "single-files"
-  },
-  {
-    "Name": "Restic Backup Example",
-    "UUID": "87654321-4321-8765-4321-876543218765",
-    "DevicePassCmd": "echo device-password",
-    "BackupRepositoryFolder": "ResticRepo",
-    "RepositoryPassCmd": "echo repo-password",
-    "FilesAndFolders": ["/tmp"]
-  }
-]
+{
+  "SudoPassCmd": "gpg --decrypt ~/.local/share/passwords/sudo-password.gpg",
+  "DeviceConfigurations": [
+    {
+      "Name": "BtrFS Backup Example",
+      "UUID": "12345678-1234-5678-1234-567812345678",
+      "DevicePassCmd": "echo device-password",
+      "BackupRepositoryFolder": "ButterBackupRepo",
+      "Compression": "zstd:3",
+      "Folders": { "/tmp": "temp-files" },
+      "Files": [],
+      "FilesDest": "single-files"
+    },
+    {
+      "Name": "Restic Backup Example",
+      "UUID": "87654321-4321-8765-4321-876543218765",
+      "DevicePassCmd": "echo device-password",
+      "BackupRepositoryFolder": "ResticRepo",
+      "RepositoryPassCmd": "echo repo-password",
+      "FilesAndFolders": ["/tmp"]
+    }
+  ]
+}

examples/json5.cfg

@@ -1,21 +1,24 @@
 // JSON5 allows comments and trailing commas
-[
-  {
-    Name: "BtrFS Backup Example",
-    UUID: "12345678-1234-5678-1234-567812345678",
-    DevicePassCmd: "echo device-password",
-    BackupRepositoryFolder: "ButterBackupRepo",
-    Compression: "zstd:3",
-    Folders: { "/tmp": "temp-files" },
-    Files: [],
-    FilesDest: "single-files",
-  },
-  {
-    Name: "Restic Backup Example",
-    UUID: "87654321-4321-8765-4321-876543218765",
-    DevicePassCmd: "echo device-password",
-    BackupRepositoryFolder: "ResticRepo",
-    RepositoryPassCmd: "echo repo-password",
-    FilesAndFolders: ["/tmp"],
-  },
-]
+{
+  SudoPassCmd: "gpg --decrypt ~/.local/share/passwords/sudo-password.gpg",
+  DeviceConfigurations: [
+    {
+      Name: "BtrFS Backup Example",
+      UUID: "12345678-1234-5678-1234-567812345678",
+      DevicePassCmd: "echo device-password",
+      BackupRepositoryFolder: "ButterBackupRepo",
+      Compression: "zstd:3",
+      Folders: { "/tmp": "temp-files" },
+      Files: [],
+      FilesDest: "single-files",
+    },
+    {
+      Name: "Restic Backup Example",
+      UUID: "87654321-4321-8765-4321-876543218765",
+      DevicePassCmd: "echo device-password",
+      BackupRepositoryFolder: "ResticRepo",
+      RepositoryPassCmd: "echo repo-password",
+      FilesAndFolders: ["/tmp"],
+    },
+  ],
+}

examples/toml.cfg

@@ -1,7 +1,10 @@
 # TOML configuration for butter-backup
-# Each [[DEVICE_CONFIGURATION]] section defines one device configuration
+# Each [[butter-backup.device-configurations]] section defines one device configuration
 
-[[DEVICE_CONFIGURATION]]
+[butter-backup]
+SudoPassCmd = "gpg --decrypt ~/.local/share/passwords/sudo-password.gpg"
+
+[[butter-backup.device-configurations]]
 Name = "BtrFS Backup Example"
 UUID = "12345678-1234-5678-1234-567812345678"
 DevicePassCmd = "echo device-password"
@@ -10,10 +13,10 @@ Compression = "zstd:3"
 Files = []
 FilesDest = "single-files"
 
-[DEVICE_CONFIGURATION.Folders]
+[butter-backup.device-configurations.Folders]
 "/tmp" = "temp-files"
 
-[[DEVICE_CONFIGURATION]]
+[[butter-backup.device-configurations]]
 Name = "Restic Backup Example"
 UUID = "87654321-4321-8765-4321-876543218765"
 DevicePassCmd = "echo device-password"

examples/yaml.cfg

@@ -1,18 +1,20 @@
 ---
-- Name: "BtrFS Backup Example"
-  UUID: "12345678-1234-5678-1234-567812345678"
-  DevicePassCmd: "echo device-password"
-  BackupRepositoryFolder: "ButterBackupRepo"
-  Compression: "zstd:3"
-  Folders:
-    /tmp: "temp-files"
-  Files: []
-  FilesDest: "single-files"
+SudoPassCmd: "gpg --decrypt ~/.local/share/passwords/sudo-password.gpg"
+DeviceConfigurations:
+  - Name: "BtrFS Backup Example"
+    UUID: "12345678-1234-5678-1234-567812345678"
+    DevicePassCmd: "echo device-password"
+    BackupRepositoryFolder: "ButterBackupRepo"
+    Compression: "zstd:3"
+    Folders:
+      /tmp: "temp-files"
+    Files: []
+    FilesDest: "single-files"
 
-- Name: "Restic Backup Example"
-  UUID: "87654321-4321-8765-4321-876543218765"
-  DevicePassCmd: "echo device-password"
-  BackupRepositoryFolder: "ResticRepo"
-  RepositoryPassCmd: "echo repo-password"
-  FilesAndFolders:
-    - /tmp
+  - Name: "Restic Backup Example"
+    UUID: "87654321-4321-8765-4321-876543218765"
+    DevicePassCmd: "echo device-password"
+    BackupRepositoryFolder: "ResticRepo"
+    RepositoryPassCmd: "echo repo-password"
+    FilesAndFolders:
+      - /tmp

src/butter_backup/backup_backends.py

@@ -11,9 +11,16 @@
 from . import config_parser as cp
 
 
+def _refresh_sudo(sudo_pass_cmd: str | None) -> None:
+    if sudo_pass_cmd is not None:
+        sh.pipe_pass_cmd_to_real_cmd(
+            sudo_pass_cmd, ["sudo", "-Sv"], capture_output=True
+        )
+
+
 class BackupBackend(abc.ABC):
     @abc.abstractmethod
-    def do_backup(self, mount_dir: Path) -> None: ...
+    def do_backup(self, mount_dir: Path, sudo_pass_cmd: str | None = None) -> None: ...
 
     @overload
     @staticmethod
@@ -37,25 +44,28 @@ def from_config(
 class BtrFSRsyncBackend(BackupBackend):
     config: cp.BtrFSRsyncConfig
 
-    def do_backup(self, mount_dir: Path) -> None:
+    def do_backup(self, mount_dir: Path, sudo_pass_cmd: str | None = None) -> None:
         logger.info(f"Beginne mit BtrFS-Backup für Speichermedium {self.config.Name}.")
         backup_repository = mount_dir / self.config.BackupRepositoryFolder
         src_snapshot = self.get_source_snapshot(backup_repository)
         logger.info(f"Basis-Sicherungskopie: {src_snapshot}.")
         backup_root = self.snapshot(
             src=src_snapshot, backup_repository=backup_repository
         )
+        _refresh_sudo(sudo_pass_cmd)
         self.adapt_ownership(backup_root)
 
         for src, dest_name in self.config.Folders.items():
             dest = backup_root / dest_name
+            _refresh_sudo(sudo_pass_cmd)
             self.rsync_folder(src, dest, self.config.ExcludePatternsFile)
 
         files_dest = backup_root / self.config.FilesDest
         if files_dest.is_file():
             files_dest.unlink()
         files_dest.mkdir(parents=True, exist_ok=True)
         for src in self.config.Files:
+            _refresh_sudo(sudo_pass_cmd)
             self.rsync_file(src, files_dest)
 
     @staticmethod
@@ -129,10 +139,12 @@ def rsync_folder(
 class ResticBackend(BackupBackend):
     config: cp.ResticConfig
 
-    def do_backup(self, mount_dir: Path) -> None:
+    def do_backup(self, mount_dir: Path, sudo_pass_cmd: str | None = None) -> None:
         logger.info(f"Beginne mit Restic-Backup für Speichermedium {self.config.Name}.")
         backup_repository = mount_dir / self.config.BackupRepositoryFolder
+        _refresh_sudo(sudo_pass_cmd)
         self.copy_files(backup_repository)
+        _refresh_sudo(sudo_pass_cmd)
         self.adapt_ownership(backup_repository)
 
     @staticmethod

src/butter_backup/cli.py

@@ -9,6 +9,7 @@
 from tempfile import mkdtemp
 from typing import Any, Callable
 
+import shell_interface as sh
 import storage_device_managers as sdm
 import typer
 from loguru import logger
@@ -70,11 +71,18 @@ def _get_default_file_system(backend: ValidBackends) -> ValidFileSystems:
             t.assert_never(backend)
 
 
+def _refresh_sudo(sudo_pass_cmd: str | None) -> None:
+    if sudo_pass_cmd is not None:
+        sh.pipe_pass_cmd_to_real_cmd(
+            sudo_pass_cmd, ["sudo", "-Sv"], capture_output=True
+        )
+
+
 def _skip_device(
-    config: cp.Configuration,
+    config: cp.DeviceConfiguration,
     *,
-    log_missing: Callable[[cp.Configuration], None] | None = None,
-    log_opened: Callable[[cp.Configuration], None] | None = None,
+    log_missing: Callable[[cp.DeviceConfiguration], None] | None = None,
+    log_opened: Callable[[cp.DeviceConfiguration], None] | None = None,
 ) -> bool:
     """
     Helper function to determine whether a device should be skipped.
@@ -102,10 +110,13 @@ def _skip_device(
 VERBOSITY_OPTION = typer.Option(0, "--verbose", "-v", count=True)
 
 
-def _open_device(cfg: cp.Configuration, base_dir: Path) -> None:
+def _open_device(
+    cfg: cp.DeviceConfiguration, base_dir: Path, sudo_pass_cmd: str | None
+) -> None:
     mount_dir = base_dir / cfg.Name
     mount_dir.mkdir(exist_ok=True)
     try:
+        _refresh_sudo(sudo_pass_cmd)
         decrypted = sdm.open_encrypted_device(cfg.device(), cfg.DevicePassCmd)
         sdm.mount_device(decrypted, mount_dir=mount_dir, compression=cfg.compression())
     except:
@@ -143,17 +154,17 @@ def open(  # noqa: A001
     Andernfalls wird ein temporäres Verzeichnis erstellt.
     """
     setup_logging(verbose)
-    configurations = cp.parse_configuration(config.read_text())
+    parsed_config = cp.parse_configuration(config.read_text())
     base_dir = dest if dest is not None else Path(mkdtemp())
-    for cfg in configurations:
+    for cfg in parsed_config.DeviceConfigurations:
         if _skip_device(
             cfg,
             log_opened=lambda cfg: logger.warning(
                 f"Speichermedium {cfg.Name} ist bereits geöffnet. Es wird übersprungen."
             ),
         ):
             continue
-        _open_device(cfg, base_dir)
+        _open_device(cfg, base_dir, parsed_config.SudoPassCmd)
 
 
 @app.command()
@@ -166,9 +177,9 @@ def close(config: Path = CONFIG_OPTION, verbose: int = VERBOSITY_OPTION) -> None
     `open`. Weitere Erklärungen finden sich dort.
     """
     setup_logging(verbose)
-    configurations = cp.parse_configuration(config.read_text())
+    parsed_config = cp.parse_configuration(config.read_text())
     mounted_devices = sdm.get_mounted_devices()
-    for cfg in configurations:
+    for cfg in parsed_config.DeviceConfigurations:
         map_name = cfg.map_name()
         map_name_as_str = str(map_name)
         if cfg.device().exists() and map_name_as_str in mounted_devices:
@@ -182,6 +193,7 @@ def close(config: Path = CONFIG_OPTION, verbose: int = VERBOSITY_OPTION) -> None
                     device=cfg.Name,
                 )
                 continue
+            _refresh_sudo(parsed_config.SudoPassCmd)
             sdm.unmount_device(map_name)
             sdm.close_decrypted_device(map_name)
 
@@ -207,8 +219,8 @@ def backup(config: Path = CONFIG_OPTION, verbose: int = VERBOSITY_OPTION) -> Non
     weitere manuelle Schritte sind nicht nötig.
     """
     setup_logging(verbose)
-    configurations = cp.parse_configuration(config.read_text())
-    for cfg in configurations:
+    parsed_config = cp.parse_configuration(config.read_text())
+    for cfg in parsed_config.DeviceConfigurations:
         if _skip_device(
             cfg,
             log_missing=lambda cfg: logger.info(
@@ -220,9 +232,14 @@ def backup(config: Path = CONFIG_OPTION, verbose: int = VERBOSITY_OPTION) -> Non
         ):
             continue
         backend = bb.BackupBackend.from_config(cfg)
+        _refresh_sudo(parsed_config.SudoPassCmd)
         with sdm.decrypted_device(cfg.device(), cfg.DevicePassCmd) as decrypted:
             with sdm.mounted_device(decrypted, cfg.compression()) as mount_dir:
-                backend.do_backup(mount_dir)
+                backend.do_backup(mount_dir, parsed_config.SudoPassCmd)
+                # A backup could take so long that the sudo session expires. In this
+                # case the user would have to enter the password again to unmount and
+                # close the device. To prevent this, the sudo session is refreshed.
+                _refresh_sudo(parsed_config.SudoPassCmd)
 
 
 @app.command()
@@ -278,7 +295,7 @@ def format_device(
                 "Zieldatei für ButterBackup-Konfiguration existiert schon!"
             )
         config_writer = config_to.write_text
-    config: cp.Configuration
+    config: cp.DeviceConfiguration
     match backend:
         case ValidBackends.btrfs_rsync:
             config = prepare_device_for_butterbackend(device)
@@ -287,7 +304,8 @@ def format_device(
         case _:
             t.assert_never(backend)
     json_serialisable = json.loads(config.model_dump_json(exclude_none=True))
-    config_writer(json.dumps([json_serialisable], indent=4, sort_keys=True))
+    wrapper = {"DeviceConfigurations": [json_serialisable]}
+    config_writer(json.dumps(wrapper, indent=4, sort_keys=True))
 
 
 @app.command()