tests: Test termination logic under default conditions

Do not use the `provider_wait` fixture in our termination logic tests,
and switch instead to the `provider` fixture, which instantiates a
typical isolation provider.

The `provider_wait` fixture's goal was to emulate how would the process
behave if it had fully spawned. In practice, this masked some
termination logic issues that became apparent in the WIP on-host
conversion PR. Now that we kill the spawned process via its process
group, we can just use the default isolation provider in our tests.

In practice, in this PR we just do `s/provider_wait/provider`, and
remove some stale code.

tests/isolation_provider/base.py

@@ -83,18 +83,18 @@ class IsolationProviderTermination:
 
     def test_completed(
         self,
-        provider_wait: base.IsolationProvider,
+        provider: base.IsolationProvider,
         mocker: MockerFixture,
     ) -> None:
         # Check that we don't need to terminate any process, if the conversion completes
         # successfully.
         doc = Document()
-        provider_wait.progress_callback = mocker.MagicMock()
-        get_proc_exception_spy = mocker.spy(provider_wait, "get_proc_exception")
-        terminate_proc_spy = mocker.spy(provider_wait, "terminate_doc_to_pixels_proc")
+        provider.progress_callback = mocker.MagicMock()
+        get_proc_exception_spy = mocker.spy(provider, "get_proc_exception")
+        terminate_proc_spy = mocker.spy(provider, "terminate_doc_to_pixels_proc")
         popen_kill_spy = mocker.spy(subprocess.Popen, "kill")
 
-        with provider_wait.doc_to_pixels_proc(doc) as proc:
+        with provider.doc_to_pixels_proc(doc) as proc:
             assert proc.stdin
             proc.stdin.close()
             proc.wait(TIMEOUT_STARTUP)
@@ -106,18 +106,18 @@ def test_completed(
 
     def test_linger_terminate(
         self,
-        provider_wait: base.IsolationProvider,
+        provider: base.IsolationProvider,
         mocker: MockerFixture,
     ) -> None:
         # Check that successful conversions that linger for a little while are
         # terminated gracefully.
         doc = Document()
-        provider_wait.progress_callback = mocker.MagicMock()
-        get_proc_exception_spy = mocker.spy(provider_wait, "get_proc_exception")
-        terminate_proc_spy = mocker.spy(provider_wait, "terminate_doc_to_pixels_proc")
+        provider.progress_callback = mocker.MagicMock()
+        get_proc_exception_spy = mocker.spy(provider, "get_proc_exception")
+        terminate_proc_spy = mocker.spy(provider, "terminate_doc_to_pixels_proc")
         popen_kill_spy = mocker.spy(subprocess.Popen, "kill")
 
-        with provider_wait.doc_to_pixels_proc(doc) as proc:
+        with provider.doc_to_pixels_proc(doc) as proc:
             # We purposefully do nothing here, so that the process remains running.
             pass
 
@@ -128,21 +128,21 @@ def test_linger_terminate(
 
     def test_linger_kill(
         self,
-        provider_wait: base.IsolationProvider,
+        provider: base.IsolationProvider,
         mocker: MockerFixture,
     ) -> None:
         # Check that successful conversions that cannot be terminated gracefully, are
         # killed forcefully.
         doc = Document()
-        get_proc_exception_spy = mocker.spy(provider_wait, "get_proc_exception")
+        get_proc_exception_spy = mocker.spy(provider, "get_proc_exception")
         # We mock the terminate_doc_to_pixels_proc() method, so that the process must be
         # killed.
         terminate_proc_mock = mocker.patch.object(
-            provider_wait, "terminate_doc_to_pixels_proc", return_value=None
+            provider, "terminate_doc_to_pixels_proc", return_value=None
         )
         kill_pg_spy = mocker.spy(base, "kill_process_group")
 
-        with provider_wait.doc_to_pixels_proc(doc, timeout_grace=0) as proc:
+        with provider.doc_to_pixels_proc(doc, timeout_grace=0) as proc:
             pass
 
         get_proc_exception_spy.assert_not_called()
@@ -152,26 +152,24 @@ def test_linger_kill(
 
     def test_linger_unkillable(
         self,
-        provider_wait: base.IsolationProvider,
+        provider: base.IsolationProvider,
         mocker: MockerFixture,
     ) -> None:
         # Check that if a conversion process cannot be killed, at least it will not
         # block the operation.
         doc = Document()
-        get_proc_exception_spy = mocker.spy(provider_wait, "get_proc_exception")
+        get_proc_exception_spy = mocker.spy(provider, "get_proc_exception")
         # We mock both the terminate_doc_to_pixels_proc() method, and our kill
         # invocation, so that the process will seem as unkillable.
-        terminate_proc_orig = provider_wait.terminate_doc_to_pixels_proc
+        terminate_proc_orig = provider.terminate_doc_to_pixels_proc
         terminate_proc_mock = mocker.patch.object(
-            provider_wait, "terminate_doc_to_pixels_proc", return_value=None
+            provider, "terminate_doc_to_pixels_proc", return_value=None
         )
         kill_pg_mock = mocker.patch(
             "dangerzone.isolation_provider.base.kill_process_group", return_value=None
         )
 
-        with provider_wait.doc_to_pixels_proc(
-            doc, timeout_grace=0, timeout_force=0
-        ) as proc:
+        with provider.doc_to_pixels_proc(doc, timeout_grace=0, timeout_force=0) as proc:
             pass
 
         get_proc_exception_spy.assert_not_called()
@@ -180,28 +178,28 @@ def test_linger_unkillable(
         assert proc.poll() is None
 
         # Reset the function to the original state.
-        provider_wait.terminate_doc_to_pixels_proc = terminate_proc_orig  # type: ignore [method-assign]
+        provider.terminate_doc_to_pixels_proc = terminate_proc_orig  # type: ignore [method-assign]
 
         # Really kill the spawned process, so that it doesn't linger after the tests
         # complete.
-        provider_wait.ensure_stop_doc_to_pixels_proc(doc, proc)
+        provider.ensure_stop_doc_to_pixels_proc(doc, proc)
         assert proc.poll() is not None
 
     def test_failed(
         self,
-        provider_wait: base.IsolationProvider,
+        provider: base.IsolationProvider,
         mocker: MockerFixture,
     ) -> None:
         # Check that we don't need to terminate any process, if the conversion fails.
         # However, we should be able to get the return code.
         doc = Document()
-        provider_wait.progress_callback = mocker.MagicMock()
-        get_proc_exception_spy = mocker.spy(provider_wait, "get_proc_exception")
-        terminate_proc_spy = mocker.spy(provider_wait, "terminate_doc_to_pixels_proc")
+        provider.progress_callback = mocker.MagicMock()
+        get_proc_exception_spy = mocker.spy(provider, "get_proc_exception")
+        terminate_proc_spy = mocker.spy(provider, "terminate_doc_to_pixels_proc")
         popen_kill_spy = mocker.spy(subprocess.Popen, "kill")
 
         with pytest.raises(errors.DocFormatUnsupported):
-            with provider_wait.doc_to_pixels_proc(doc, timeout_exception=0) as proc:
+            with provider.doc_to_pixels_proc(doc, timeout_exception=0) as proc:
                 assert proc.stdin
                 # Sending an invalid file to the conversion process should report it as
                 # an unsupported format.
@@ -220,19 +218,19 @@ def test_failed(
 
     def test_failed_linger(
         self,
-        provider_wait: base.IsolationProvider,
+        provider: base.IsolationProvider,
         mocker: MockerFixture,
     ) -> None:
         # Check that if the failed process has not exited, the error code that will be
         # returned is UnexpectedExceptionError.
         doc = Document()
-        provider_wait.progress_callback = mocker.MagicMock()
-        get_proc_exception_spy = mocker.spy(provider_wait, "get_proc_exception")
-        terminate_proc_spy = mocker.spy(provider_wait, "terminate_doc_to_pixels_proc")
+        provider.progress_callback = mocker.MagicMock()
+        get_proc_exception_spy = mocker.spy(provider, "get_proc_exception")
+        terminate_proc_spy = mocker.spy(provider, "terminate_doc_to_pixels_proc")
         popen_kill_spy = mocker.spy(subprocess.Popen, "kill")
 
         with pytest.raises(errors.UnexpectedConversionError):
-            with provider_wait.doc_to_pixels_proc(doc, timeout_exception=0) as proc:
+            with provider.doc_to_pixels_proc(doc, timeout_exception=0) as proc:
                 raise errors.ConverterProcException
 
         get_proc_exception_spy.assert_called()

tests/isolation_provider/test_container.py

@@ -3,10 +3,7 @@
 import time
 
 import pytest
-from pytest_mock import MockerFixture
 
-from dangerzone.document import Document
-from dangerzone.isolation_provider import base
 from dangerzone.isolation_provider.container import Container
 from dangerzone.isolation_provider.qubes import is_qubes_native_conversion
 
@@ -54,49 +51,4 @@ class TestContainer(IsolationProviderTest):
 
 
 class TestContainerTermination(IsolationProviderTermination):
-    def test_linger_runtime_kill(
-        self,
-        provider_wait: base.IsolationProvider,
-        mocker: MockerFixture,
-    ) -> None:
-        # Check that conversions that remain stuck on `docker|podman kill` are
-        # terminated forcefully.
-        doc = Document()
-        provider_wait.progress_callback = mocker.MagicMock()
-        get_proc_exception_spy = mocker.spy(provider_wait, "get_proc_exception")
-        terminate_proc_spy = mocker.spy(provider_wait, "terminate_doc_to_pixels_proc")
-        kill_proc_spy = mocker.spy(base, "kill_process_group")
-
-        # Switch the subprocess.run() function with a patched function that
-        # intercepts the `kill` command and switches it with `wait` instead. This way,
-        # we emulate a `docker|podman kill` command that has hang.
-        orig_subprocess_run = subprocess.run
-
-        def patched_subprocess_run(*args, **kwargs):  # type: ignore [no-untyped-def]
-            assert len(args) == 1
-            cmd = args[0]
-            if cmd[1] == "kill":
-                # Switch the `kill` command with `wait`, thereby triggering a timeout.
-                cmd[1] = "wait"
-
-                # Make sure that a timeout has been specified, and make it 0, so that
-                # the test ends us quickly as possible.
-                assert "timeout" in kwargs
-                kwargs[timeout] = 0
-
-                # Make sure that the modified command times out.
-                with pytest.raises(subprocess.TimeoutExpired):
-                    orig_subprocess_run(cmd, **kwargs)
-            else:
-                return orig_subprocess_run(*args, **kwargs)
-
-        mocker.patch("subprocess.run", patched_subprocess_run)
-
-        with provider_wait.doc_to_pixels_proc(doc, timeout_grace=0) as proc:
-            # We purposefully do nothing here, so that the process remains running.
-            pass
-
-        get_proc_exception_spy.assert_not_called()
-        terminate_proc_spy.assert_called()
-        kill_proc_spy.assert_called()
-        assert proc.poll() is not None
+    pass