tests: add pytest framework for vdkr and vpdmn

Add pytest-based test suite for testing vdkr and vpdmn CLI tools.
Tests use a separate state directory (~/.vdkr-test/) to avoid
interfering with production images.

Test files:
- conftest.py: Pytest fixtures for VdkrRunner and VpdmnRunner
- test_vdkr.py: Docker CLI tests (images, vimport, vrun, volumes, etc.)
- test_vpdmn.py: Podman CLI tests (mirrors vdkr test coverage)
- memres-test.sh: Helper script for running tests with memres
- pytest.ini: Pytest configuration and markers

Test categories:
- Basic operations: images, info, version
- Import/export: vimport, load, save
- Container execution: vrun, run, exec
- Storage management: system df, vstorage
- Memory resident mode: memres/vmemres start/stop/status

Running tests:
    pytest tests/test_vdkr.py -v --vdkr-dir /tmp/vcontainer-standalone
    pytest tests/test_vpdmn.py -v --vdkr-dir /tmp/vcontainer-standalone

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/tests/pytest.ini b/tests/pytest.ini
new file mode 100644
index 00000000..b0a51f7e
--- /dev/null
+++ b/tests/pytest.ini
@@ -0,0 +1,29 @@
+[pytest]
+testpaths = .
+python_files = test_*.py
+python_classes = Test*
+python_functions = test_*
+
+# Markers
+markers =
+    slow: marks tests as slow (deselect with '-m "not slow"')
+    memres: marks tests that require memory resident mode
+    network: marks tests that require network access
+    boot: marks tests that boot a full QEMU image (requires pexpect)
+
+# Default options - include junit xml for CI and detailed output
+addopts = -v --tb=short --junitxml=/tmp/pytest-results.xml
+
+# Log file for test output (always written, survives test runs)
+log_file = /tmp/pytest-vcontainer.log
+log_file_level = DEBUG
+log_file_format = %(asctime)s %(levelname)s %(message)s
+log_file_date_format = %Y-%m-%d %H:%M:%S
+
+# Also show logs on console during test run
+log_cli = false
+log_cli_level = INFO
+
+# Ignore warnings from subprocess
+filterwarnings =
+    ignore::DeprecationWarning