Catch installation errors and display them.

Fixes #193

dangerzone/gui/main_window.py

@@ -20,15 +20,20 @@
         from PySide6.QtWidgets import QTextEdit
     except ImportError:
         from PySide2 import QtCore, QtGui, QtSvg, QtWidgets
-        from PySide2.QtWidgets import QAction, QTextEdit
         from PySide2.QtCore import Qt
+        from PySide2.QtWidgets import QAction, QTextEdit
 
 from .. import errors
 from ..document import SAFE_EXTENSION, Document
 from ..isolation_provider.container import Container, NoContainerTechException
 from ..isolation_provider.dummy import Dummy
 from ..isolation_provider.qubes import Qubes, is_qubes_native_conversion
-from ..util import get_resource_path, get_subprocess_startupinfo, get_version
+from ..util import (
+    format_exception,
+    get_resource_path,
+    get_subprocess_startupinfo,
+    get_version,
+)
 from .logic import Alert, CollapsibleBox, DangerzoneGui, UpdateDialog
 from .updater import UpdateReport
 
@@ -388,15 +393,24 @@ def closeEvent(self, e: QtGui.QCloseEvent) -> None:
 
 
 class InstallContainerThread(QtCore.QThread):
-    finished = QtCore.Signal()
+    finished = QtCore.Signal(str)
 
     def __init__(self, dangerzone: DangerzoneGui) -> None:
         super(InstallContainerThread, self).__init__()
         self.dangerzone = dangerzone
 
     def run(self) -> None:
-        self.dangerzone.isolation_provider.install()
-        self.finished.emit()
+        error = None
+        try:
+            installed = self.dangerzone.isolation_provider.install()
+        except Exception as e:
+            log.error("Container installation problem")
+            error = format_exception(e)
+        else:
+            if not installed:
+                error = "The image cannot be found. This can be caused by a faulty container image."
+        finally:
+            self.finished.emit(error)
 
 
 class WaitingWidget(QtWidgets.QWidget):
@@ -423,9 +437,10 @@ def __init__(self) -> None:
         # Enable copying
         self.setTextInteractionFlags(Qt.TextSelectableByMouse)
 
-    def set_content(self, error: str) -> None:
-        self.setPlainText(error)
-        self.setVisible(True)
+    def set_content(self, error: Optional[str] = None) -> None:
+        if error:
+            self.setPlainText(error)
+            self.setVisible(True)
 
 
 class WaitingWidgetContainer(WaitingWidget):
@@ -438,7 +453,6 @@ class WaitingWidgetContainer(WaitingWidget):
     #
     # Linux states
     # - "install_container"
-    finished = QtCore.Signal()
 
     def __init__(self, dangerzone: DangerzoneGui) -> None:
         super(WaitingWidgetContainer, self).__init__()
@@ -509,48 +523,64 @@ def check_state(self) -> None:
         # Update the state
         self.state_change(state, error)
 
+    def show_error(self, msg: str, details: Optional[str] = None) -> None:
+        self.label.setText(msg)
+        show_traceback = details is not None
+        if show_traceback:
+            self.traceback.set_content(details)
+        self.traceback.setVisible(show_traceback)
+        self.buttons.show()
+
+    def show_message(self, msg: str) -> None:
+        self.label.setText(msg)
+        self.traceback.setVisible(False)
+        self.buttons.hide()
+
+    def installation_finished(self, error: Optional[str] = None) -> None:
+        if error:
+            msg = (
+                "During installation of the dangerzone image, <br>"
+                "the following error occured:"
+            )
+            self.show_error(msg, error)
+        else:
+            self.finished.emit()
+
     def state_change(self, state: str, error: Optional[str] = None) -> None:
         if state == "not_installed":
             if platform.system() == "Linux":
-                self.label.setText(
+                self.show_error(
                     "<strong>Dangerzone requires Podman</strong><br><br>"
                     "Install it and retry."
                 )
             else:
-                self.label.setText(
+                self.show_error(
                     "<strong>Dangerzone requires Docker Desktop</strong><br><br>"
                     "<a href='https://www.docker.com/products/docker-desktop'>Download Docker Desktop</a>"
                     ", install it, and open it."
                 )
-            self.buttons.show()
+
         elif state == "not_running":
             if platform.system() == "Linux":
                 # "not_running" here means that the `podman image ls` command failed.
                 message = (
                     "<strong>Dangerzone requires Podman</strong><br><br>"
                     "Podman is installed but cannot run properly. See errors below"
                 )
-                if error:
-                    self.traceback.set_content(error)
-
-                self.label.setText(message)
-
             else:
-                self.label.setText(
+                message = (
                     "<strong>Dangerzone requires Docker Desktop</strong><br><br>"
                     "Docker is installed but isn't running.<br><br>"
                     "Open Docker and make sure it's running in the background."
                 )
-            self.buttons.show()
+            self.show_error(message, error)
         else:
-            self.label.setText(
+            self.show_message(
                 "Installing the Dangerzone container image.<br><br>"
                 "This might take a few minutes..."
             )
-            self.buttons.hide()
-            self.traceback.setVisible(False)
             self.install_container_t = InstallContainerThread(self.dangerzone)
-            self.install_container_t.finished.connect(self.finished)
+            self.install_container_t.finished.connect(self.installation_finished)
             self.install_container_t.start()
 
 

dangerzone/isolation_provider/container.py

@@ -165,7 +165,7 @@ def install() -> bool:
             startupinfo=get_subprocess_startupinfo(),
         )
 
-        chunk_size = 10240
+        chunk_size = 4 << 20
         compressed_container_path = get_resource_path("container.tar.gz")
         with gzip.open(compressed_container_path) as f:
             while True:
@@ -175,19 +175,20 @@ def install() -> bool:
                         p.stdin.write(chunk)
                 else:
                     break
-        p.communicate()
+        _, err = p.communicate()
+        if p.returncode < 0:
+            raise RuntimeError(f"Could not install container image: {err.decode()}")
 
-        if not Container.is_container_installed():
-            log.error("Failed to install the container image")
+        if not Container.is_container_installed(raise_on_error=True):
             return False
 
         log.info("Container image installed")
         return True
 
     @staticmethod
-    def is_container_installed() -> bool:
+    def is_container_installed(raise_on_error: bool = False) -> bool:
         """
-        See if the podman container is installed. Linux only.
+        See if the container is installed.
         """
         # Get the image id
         with open(get_resource_path("image-id.txt")) as f:
@@ -214,6 +215,13 @@ def is_container_installed() -> bool:
         elif found_image_id == "":
             pass
         else:
+            msg = (
+                f"{Container.CONTAINER_NAME} images found, but IDs do not match."
+                f"Found: {found_image_id}, Expected: {','.join(expected_image_ids)}"
+            )
+            if raise_on_error:
+                raise RuntimeError(msg)
+            log.info(msg)
             log.info("Deleting old dangerzone container image")
 
             try:

dangerzone/util.py

@@ -2,6 +2,7 @@
 import platform
 import subprocess
 import sys
+import traceback
 import unicodedata
 from typing import Optional
 
@@ -97,3 +98,13 @@ def is_safe(chr: str) -> bool:
         else:
             sanitized_str += "�"
     return sanitized_str
+
+
+def format_exception(e: Exception) -> str:
+    # The signature of traceback.format_exception has changed in python 3.10
+    if sys.version_info < (3, 10):
+        output = traceback.format_exception(*sys.exc_info())
+    else:
+        output = traceback.format_exception(e)
+
+    return "".join(output)

pyproject.toml

@@ -50,6 +50,7 @@ pytest-mock = "^3.10.0"
 pytest-qt = "^4.2.0"
 pytest-cov = "^5.0.0"
 strip-ansi = "*"
+pytest-subprocess = "^1.5.2"
 
 [tool.poetry.group.qubes.dependencies]
 pymupdf = "^1.23.6"

tests/gui/test_main_window.py

@@ -1,24 +1,31 @@
 import os
 import pathlib
+import platform
 import shutil
 import time
 from typing import List
 
 from pytest import MonkeyPatch, fixture
 from pytest_mock import MockerFixture
+from pytest_subprocess import FakeProcess
 from pytestqt.qtbot import QtBot
 
 from dangerzone.document import Document
 from dangerzone.gui import MainWindow
 from dangerzone.gui import main_window as main_window_module
 from dangerzone.gui import updater as updater_module
 from dangerzone.gui.logic import DangerzoneGui
-from dangerzone.gui.main_window import (  # import Pyside related objects from here to avoid duplicating import logic.
+
+# import Pyside related objects from here to avoid duplicating import logic.
+from dangerzone.gui.main_window import (
     ContentWidget,
+    InstallContainerThread,
     QtCore,
     QtGui,
+    WaitingWidgetContainer,
 )
 from dangerzone.gui.updater import UpdateReport, UpdaterThread
+from dangerzone.isolation_provider.container import Container
 
 from .test_updater import assert_report_equal, default_updater_settings
 
@@ -492,3 +499,87 @@ def test_drop_1_invalid_2_valid_documents(
         content_widget.doc_selection_wrapper.dropEvent(
             drag_1_invalid_and_2_valid_files_event
         )
+
+
+def test_installation_image_ls_error(
+    qtbot: QtBot, mocker: MockerFixture, fp: FakeProcess
+):
+    # Setup
+    mock_app = mocker.MagicMock()
+    dummy = mocker.MagicMock(spec=Container)
+    dummy.get_runtime.return_value = "podman"
+
+    # Make "podman image ls" return an error
+    fp.register_subprocess(
+        ["podman", "image", "ls"], returncode=-1, stderr="podman image ls logs"
+    )
+    fp.pass_command(["xdg-mime", "query", "default", "application/pdf"])
+
+    dz = DangerzoneGui(mock_app, dummy)
+    widget = WaitingWidgetContainer(dz)
+    qtbot.addWidget(widget)
+
+    # Assert that the error is displayed in the GUI
+    if platform.system() in ["Darwin", "Windows"]:
+        assert "Dangerzone requires Docker Desktop" in widget.label.text()
+    else:
+        assert "Podman is installed but cannot run properly" in widget.label.text()
+
+    assert "podman image ls logs" in widget.traceback.toPlainText()
+
+
+def test_installation_failure_exception(
+    qtbot: QtBot, mocker: MockerFixture, fp: FakeProcess
+):
+    # Setup
+    mock_app = mocker.MagicMock()
+    dummy = mocker.MagicMock(spec=Container)
+    dummy.get_runtime.return_value = "podman"
+    dummy.install.side_effect = RuntimeError("Error during install")
+
+    # Make "podman image ls" return an error
+    fp.register_subprocess(["podman", "image", "ls"], returncode=0)
+    fp.pass_command(["xdg-mime", "query", "default", "application/pdf"])
+
+    dz = DangerzoneGui(mock_app, dummy)
+    widget = WaitingWidgetContainer(dz)
+    qtbot.addWidget(widget)
+
+    # Assert that the error is displayed in the GUI
+    assert "Installing the Dangerzone container image" in widget.label.text()
+    # Start the installation process
+    install_thread = InstallContainerThread(dz)
+    with qtbot.waitSignal(install_thread.finished, timeout=5000):
+        install_thread.start()
+
+    assert "the following error occured" in widget.label.text()
+    assert "Traceback" in widget.traceback.toPlainText()
+    assert "Error during install" in widget.traceback.toPlainText()
+
+
+def test_installation_failure_return_false(
+    qtbot: QtBot, mocker: MockerFixture, fp: FakeProcess
+):
+    # Setup
+    mock_app = mocker.MagicMock()
+    dummy = mocker.MagicMock(spec=Container)
+    dummy.get_runtime.return_value = "podman"
+    dummy.install.return_value = False
+
+    # Make "podman image ls" return an error
+    fp.register_subprocess(["podman", "image", "ls"], returncode=0)
+    fp.pass_command(["xdg-mime", "query", "default", "application/pdf"])
+
+    dz = DangerzoneGui(mock_app, dummy)
+    widget = WaitingWidgetContainer(dz)
+    qtbot.addWidget(widget)
+
+    # Assert that the error is displayed in the GUI
+    assert "Installing the Dangerzone container image" in widget.label.text()
+    # Start the installation process
+    install_thread = InstallContainerThread(dz)
+    with qtbot.waitSignal(install_thread.finished, timeout=5000):
+        install_thread.start()
+
+    assert "the following error occured" in widget.label.text()
+    assert "The image cannot be found" in widget.traceback.toPlainText()

tests/isolation_provider/base.py

@@ -7,7 +7,6 @@
 from dangerzone.conversion import errors
 from dangerzone.document import Document
 from dangerzone.isolation_provider import base
-from dangerzone.isolation_provider.qubes import running_on_qubes
 
 TIMEOUT_STARTUP = 60  # Timeout in seconds until the conversion sandbox starts.