FIXUP: return type for mypy

This sets the container runtime in the settings, and provides an easy
way to do so for users, without having to mess with the json settings.

dangerzone/cli.py

@@ -11,6 +11,7 @@ from .isolation_provider.container import Container
 from .isolation_provider.dummy import Dummy
 from .isolation_provider.qubes import Qubes, is_qubes_native_conversion
 from .logic import DangerzoneCore
+from .settings import Settings
 from .util import get_version, replace_control_chars
 
 
@@ -48,6 +49,11 @@ def print_header(s: str) -> None:
     flag_value=True,
     help="Run Dangerzone in debug mode, to get logs from gVisor.",
 )
+@click.option(
+    "--set-container-runtime",
+    required=False,
+    help="The path to the container runtime you want to set in the settings",
+)
 @click.version_option(version=get_version(), message="%(version)s")
 @errors.handle_document_errors
 def cli_main(
@@ -57,8 +63,14 @@ def cli_main(
     archive: bool,
     dummy_conversion: bool,
     debug: bool,
+    set_container_runtime: Optional[str] = None,
 ) -> None:
     setup_logging()
+    display_banner()
+    if set_container_runtime:
+        settings = Settings()
+        settings.set("container_runtime", set_container_runtime, autosave=True)
+        click.echo(f"Set the settings container_runtime to {set_container_runtime}")
 
     if getattr(sys, "dangerzone_dev", False) and dummy_conversion:
         dangerzone = DangerzoneCore(Dummy())
@@ -67,7 +79,6 @@ def cli_main(
     else:
         dangerzone = DangerzoneCore(Container(debug=debug))
 
-    display_banner()
     if len(filenames) == 1 and output_filename:
         dangerzone.add_document_from_filename(filenames[0], output_filename, archive)
     elif len(filenames) > 1 and output_filename:
@@ -320,4 +331,10 @@ def display_banner() -> None:
         + Style.DIM
         + "│"
     )
-    print(Back.BLACK + Fore.YELLOW + Style.DIM + "╰──────────────────────────╯")
+    print(
+        Back.BLACK
+        + Fore.YELLOW
+        + Style.DIM
+        + "╰──────────────────────────╯"
+        + Style.RESET_ALL
+    )

dangerzone/container_utils.py

@@ -21,6 +21,8 @@ class Runtime(object):
 
         if settings.custom_runtime_specified():
             self.path = Path(settings.get("container_runtime"))
+            if not self.path.exists():
+                raise errors.UnsupportedContainerRuntime(self.path)
             self.name = self.path.stem
         else:
             self.name = self.get_default_runtime_name()
@@ -29,6 +31,9 @@ class Runtime(object):
                 raise errors.NoContainerTechException(self.name)
             self.path = Path(binary_path)
 
+        if self.name not in ("podman", "docker"):
+            raise errors.UnsupportedContainerRuntime(self.name)
+
     @staticmethod
     def get_default_runtime_name() -> str:
         return "podman" if platform.system() == "Linux" else "docker"

dangerzone/errors.py

@@ -140,3 +140,7 @@ class NotAvailableContainerTechException(Exception):
         self.error = error
         self.container_tech = container_tech
         super().__init__(f"{container_tech} is not available")
+
+
+class UnsupportedContainerRuntime(Exception):
+    pass

tests/test_container_utils.py

@@ -1,20 +1,21 @@
 from pathlib import Path
 
+import pytest
 from pytest_mock import MockerFixture
 
+from dangerzone import errors
 from dangerzone.container_utils import Runtime
 from dangerzone.settings import Settings
 
 
 def test_get_runtime_name_from_settings(mocker: MockerFixture, tmp_path: Path) -> None:
     mocker.patch("dangerzone.settings.get_config_dir", return_value=tmp_path)
+    mocker.patch("dangerzone.container_utils.Path.exists", return_value=True)
 
     settings = Settings()
-    settings.set(
-        "container_runtime", "/opt/somewhere/new-kid-on-the-block", autosave=True
-    )
+    settings.set("container_runtime", "/opt/somewhere/docker", autosave=True)
 
-    assert Runtime().name == "new-kid-on-the-block"
+    assert Runtime().name == "docker"
 
 
 def test_get_runtime_name_linux(mocker: MockerFixture, tmp_path: Path) -> None:
@@ -46,3 +47,14 @@ def test_get_runtime_name_non_linux(mocker: MockerFixture, tmp_path: Path) -> No
     assert runtime.name == "docker"
     assert runtime.path == Path("/usr/bin/docker")
     assert Runtime().name == "docker"
+
+
+def test_get_unsupported_runtime_name(mocker: MockerFixture, tmp_path: Path) -> None:
+    mocker.patch("dangerzone.settings.get_config_dir", return_value=tmp_path)
+    settings = Settings()
+    settings.set(
+        "container_runtime", "/opt/somewhere/new-kid-on-the-block", autosave=True
+    )
+
+    with pytest.raises(errors.UnsupportedContainerRuntime):
+        assert Runtime().name == "new-kid-on-the-block"