[BACKEND] Validate write permissions on working directory and output directory (#1395)

Closes https://github.com/jmbannon/ytdl-sub/issues/1394
Should help debug user issues like https://github.com/jmbannon/ytdl-sub/issues/1148

Checks permissions on the following:
- working directory
- output directory
- cookiefile (if specified)

And will fail immediately with a verbose message.

src/ytdl_sub/config/config_validator.py

@@ -12,6 +12,8 @@ from ytdl_sub.config.defaults import DEFAULT_FFPROBE_PATH
 from ytdl_sub.config.defaults import DEFAULT_LOCK_DIRECTORY
 from ytdl_sub.config.defaults import MAX_FILE_NAME_BYTES
 from ytdl_sub.prebuilt_presets import PREBUILT_PRESETS
+from ytdl_sub.utils.exceptions import SubscriptionPermissionError
+from ytdl_sub.utils.file_handler import FileHandler
 from ytdl_sub.validators.file_path_validators import FFmpegFileValidator
 from ytdl_sub.validators.file_path_validators import FFprobeFileValidator
 from ytdl_sub.validators.strict_dict_validator import StrictDictValidator
@@ -147,6 +149,12 @@ class ConfigOptions(StrictDictValidator):
             key="file_name_max_bytes", validator=IntValidator, default=MAX_FILE_NAME_BYTES
         )
 
+        if not FileHandler.is_path_writable(self.working_directory):
+            raise SubscriptionPermissionError(
+                "ytdl-sub does not have permissions to the working directory: "
+                f"{self.working_directory}"
+            )
+
     @property
     def working_directory(self) -> str:
         """

src/ytdl_sub/config/preset_options.py

@@ -8,6 +8,9 @@ from ytdl_sub.config.overrides import Overrides
 from ytdl_sub.config.plugin.plugin_operation import PluginOperation
 from ytdl_sub.config.validators.options import OptionsDictValidator
 from ytdl_sub.entries.script.variable_definitions import VARIABLES as v
+from ytdl_sub.utils.exceptions import SubscriptionPermissionError
+from ytdl_sub.utils.exceptions import ValidationException
+from ytdl_sub.utils.file_handler import FileHandler
 from ytdl_sub.validators.file_path_validators import OverridesStringFormatterFilePathValidator
 from ytdl_sub.validators.file_path_validators import StringFormatterFileNameValidator
 from ytdl_sub.validators.string_datetime import StringDatetimeValidator
@@ -57,12 +60,24 @@ class YTDLOptions(UnstructuredOverridesDictFormatterValidator):
     def to_native_dict(self, overrides: Overrides) -> Dict:
         """
         Materializes the entire ytdl-options dict from OverrideStringFormatters into
-        native python
+        native python.
         """
-        return {
+        out = {
             key: overrides.apply_overrides_formatter_to_native(val)
             for key, val in self.dict.items()
         }
+        if "cookiefile" in out:
+            if not FileHandler.is_file_existent(out["cookiefile"]):
+                raise ValidationException(
+                    f"Specified cookiefile {out['cookiefile']} but it does not exist as a file."
+                )
+
+            if not FileHandler.is_file_readable(out["cookiefile"]):
+                raise SubscriptionPermissionError(
+                    f"Cannot read cookiefile {out['cookiefile']} due to permissions issue."
+                )
+
+        return out
 
 
 # Disable for proper docstring formatting

src/ytdl_sub/subscriptions/base_subscription.py

@@ -10,6 +10,8 @@ from ytdl_sub.config.preset_options import OutputOptions
 from ytdl_sub.config.preset_options import YTDLOptions
 from ytdl_sub.downloaders.url.validators import MultiUrlValidator
 from ytdl_sub.entries.variables.override_variables import SubscriptionVariables
+from ytdl_sub.utils.exceptions import SubscriptionPermissionError
+from ytdl_sub.utils.file_handler import FileHandler
 from ytdl_sub.utils.file_handler import FileHandlerTransactionLog
 from ytdl_sub.utils.logger import Logger
 from ytdl_sub.ytdl_additions.enhanced_download_archive import EnhancedDownloadArchive
@@ -94,6 +96,12 @@ class BaseSubscription(ABC):
 
         self._exception: Optional[Exception] = None
 
+        if not FileHandler.is_path_writable(self.output_directory):
+            raise SubscriptionPermissionError(
+                "ytdl-sub does not have write permissions to the output directory: "
+                f"{self.output_directory}"
+            )
+
     @property
     def download_archive(self) -> EnhancedDownloadArchive:
         """

src/ytdl_sub/utils/exceptions.py

@@ -40,3 +40,7 @@ class FileNotDownloadedException(ValueError):
 
 class ExperimentalFeatureNotEnabled(ValidationException):
     """Feature is not enabled for usage"""
+
+
+class SubscriptionPermissionError(ValidationException):
+    """Early-caught permission error"""

src/ytdl_sub/utils/file_handler.py

@@ -379,6 +379,36 @@ class FileHandler:
         """
         return self._file_handler_transaction_log
 
+    @classmethod
+    def is_path_writable(cls, src_file_path: Union[str, Path]) -> bool:
+        """
+        Check whether a path is writable. If it does not exist, try to find the base directory
+        and check permissions on that.
+        """
+        path = os.path.abspath(src_file_path)
+
+        while not os.path.exists(path):
+            new_path = os.path.dirname(path)
+            if new_path == path:  # reached root
+                break
+            path = new_path
+
+        return os.access(path, os.W_OK)
+
+    @classmethod
+    def is_file_existent(cls, file_path: Union[str, Path]) -> bool:
+        """
+        Check whether a file exists.
+        """
+        return os.path.isfile(file_path)
+
+    @classmethod
+    def is_file_readable(cls, file_path: Union[str, Path]) -> bool:
+        """
+        Check whether a file exists and is readable.
+        """
+        return cls.is_file_existent(file_path) and os.access(file_path, os.R_OK)
+
     @classmethod
     def copy(cls, src_file_path: Union[str, Path], dst_file_path: Union[str, Path]):
         """

tests/conftest.py

@@ -13,6 +13,7 @@ from typing import Dict
 from typing import List
 from typing import Optional
 from typing import Tuple
+from typing import Union
 from unittest.mock import patch
 
 import pytest
@@ -165,19 +166,18 @@ def preset_dict_to_dl_args(preset_dict: Dict) -> str:
 
 
 @pytest.fixture
-def preset_dict_to_subscription_yaml_generator() -> Callable:
+def subscription_yaml_file_generator() -> Callable:
     @contextlib.contextmanager
-    def _preset_dict_to_subscription_yaml_generator(subscription_name: str, preset_dict: Dict):
+    def _subscription_yaml_file_generator(yaml_dict: Dict):
-        subscription_dict = {subscription_name: preset_dict}
         with tempfile.NamedTemporaryFile(suffix=".yaml", delete=False) as tmp_file:
-            tmp_file.write(json.dumps(subscription_dict).encode("utf-8"))
+            tmp_file.write(json.dumps(yaml_dict).encode("utf-8"))
 
         try:
             yield tmp_file.name
         finally:
             FileHandler.delete(tmp_file.name)
 
-    return _preset_dict_to_subscription_yaml_generator
+    return _subscription_yaml_file_generator
 
 
 ###################################################################################################
@@ -224,8 +224,14 @@ def _load_config(config_path: Path, working_directory: str) -> ConfigFile:
 
 
 @pytest.fixture()
-def music_video_subscription_path() -> Path:
+def music_video_subscription_path(
-    return Path("examples/music_video_subscriptions.yaml")
+    output_directory: str, subscription_yaml_file_generator: Callable
+) -> Path:
+    yaml = load_yaml("examples/music_video_subscriptions.yaml")
+    yaml["__preset__"]["overrides"]["music_video_directory"] = output_directory
+
+    with subscription_yaml_file_generator(yaml) as mock_filename:
+        yield mock_filename
 
 
 @pytest.fixture()
@@ -239,13 +245,25 @@ def tv_show_config(working_directory, tv_show_config_path) -> ConfigFile:
 
 
 @pytest.fixture()
-def tv_show_subscriptions_path() -> Path:
+def tv_show_subscriptions_path(
-    return Path("examples/tv_show_subscriptions.yaml")
+    output_directory: str, subscription_yaml_file_generator: Callable
+) -> Path:
+    yaml = load_yaml("examples/tv_show_subscriptions.yaml")
+    yaml["__preset__"]["overrides"]["tv_show_directory"] = output_directory
+
+    with subscription_yaml_file_generator(yaml) as mock_filename:
+        yield mock_filename
 
 
 @pytest.fixture()
-def advanced_tv_show_subscriptions_path() -> Path:
+def advanced_tv_show_subscriptions_path(
-    return Path("examples/advanced/tv_show_subscriptions.yaml")
+    output_directory: str, subscription_yaml_file_generator: Callable
+) -> Path:
+    yaml = load_yaml("examples/advanced/tv_show_subscriptions.yaml")
+    yaml["__preset__"] = {"overrides": {"tv_show_directory": output_directory}}
+
+    with subscription_yaml_file_generator(yaml) as mock_filename:
+        yield mock_filename
 
 
 @pytest.fixture()
@@ -265,8 +283,25 @@ def default_config_path(default_config) -> str:
 
 
 @pytest.fixture()
-def music_subscriptions_path() -> Path:
+def music_subscriptions_path(
-    return Path("examples/music_subscriptions.yaml")
+    output_directory: str, subscription_yaml_file_generator: Callable
+) -> Path:
+    yaml = load_yaml("examples/music_subscriptions.yaml")
+    yaml["__preset__"]["overrides"]["music_directory"] = output_directory
+
+    with subscription_yaml_file_generator(yaml) as mock_filename:
+        yield mock_filename
+
+
+@pytest.fixture()
+def docker_default_subscription_path(
+    output_directory: str, subscription_yaml_file_generator: Callable
+) -> Path:
+    yaml = load_yaml("docker/root/defaults/subscriptions.yaml")
+    yaml["__preset__"]["overrides"]["tv_show_directory"] = output_directory
+
+    with subscription_yaml_file_generator(yaml) as mock_filename:
+        yield mock_filename
 
 
 def mock_run_from_cli(args: str) -> List[Subscription]:

tests/unit/config/test_subscription.py

@@ -540,9 +540,9 @@ def test_music_video_subscriptions(default_config: ConfigFile, music_video_subsc
     assert gnr.get("url2").native == "https://www.youtube.com/watch?v=OldpIhHPsbs"
 
 
-def test_default_docker_config_and_subscriptions():
+def test_default_docker_config_and_subscriptions(docker_default_subscription_path: Path):
     default_config = ConfigFile.from_file_path("docker/root/defaults/config.yaml")
     default_subs = Subscription.from_file_path(
-        config=default_config, subscription_path=Path("docker/root/defaults/subscriptions.yaml")
+        config=default_config, subscription_path=docker_default_subscription_path
     )
     assert len(default_subs) == 1

tests/unit/plugins/test_ytdl_options.py

@@ -0,0 +1,38 @@
+import re
+from typing import Any
+from typing import Dict
+
+import pytest
+from conftest import get_match_filters
+
+from ytdl_sub.config.config_file import ConfigFile
+from ytdl_sub.subscriptions.subscription import Subscription
+from ytdl_sub.utils.exceptions import ValidationException
+
+
+@pytest.fixture
+def preset_dict(output_directory) -> Dict[str, Any]:
+    return {
+        "download": "https://your.name.here",
+        "output_options": {"output_directory": output_directory, "file_name": "will_error.mp4"},
+    }
+
+
+class TestYtdlOptions:
+    def test_cookiefile_does_not_exist(
+        self,
+        default_config: ConfigFile,
+        preset_dict: Dict[str, Any],
+    ):
+        preset_dict["ytdl_options"] = {
+            "cookiefile": "/path/to/nowhere",
+        }
+
+        error_msg = "Specified cookiefile /path/to/nowhere but it does not exist as a file."
+
+        with pytest.raises(ValidationException, match=re.escape(error_msg)):
+            Subscription.from_dict(
+                config=default_config,
+                preset_name="test_ytdl_options",
+                preset_dict=preset_dict,
+            ).download(dry_run=False)

tests/unit/utils/test_file_handler.py

@@ -0,0 +1,20 @@
+import pytest
+
+from ytdl_sub.utils.file_handler import FileHandler
+from ytdl_sub.utils.system import IS_WINDOWS
+
+
+class TestFileHandler:
+
+    def test_directory_exists(self):
+        if IS_WINDOWS:
+            return
+
+        assert FileHandler.is_path_writable("/tmp")
+        assert FileHandler.is_path_writable("/tmp/")
+        assert FileHandler.is_path_writable("/tmp/non-existent")
+        assert FileHandler.is_path_writable("/tmp/non-existent/")
+        assert FileHandler.is_path_writable("/tmp/non-existent/nested")
+
+        assert not FileHandler.is_path_writable("/lol-in-root")
+        assert not FileHandler.is_path_writable("/")