test: move container test suites to pytest (#112)

* test: scaffold pytest suite with mise, uv and Task

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* ci: run the pytest suite via mise and task

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* fix: make test cleanup survive repeated SIGINT

A group Ctrl-C reaches pytest a second time via task and uv while the
session fixture tears down, aborting the volume cleanup. Ignore SIGINT
and SIGTERM during cleanup, remove volumes in finally, and tolerate
already-removed objects.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* fix: pin Python 3.13 for uv without mise

Add .python-version (read by mise and uv) and cap requires-python at
<3.14 so bare uv uses 3.13 or fails instead of picking 3.14.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* fix: clean up test containers on SIGTERM

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* test: port compat tests to pytest

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* test: assert the success message first in the corruption test

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* test: assert the empty-tag snapshot carries no tags

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* test: remove anonymous volumes with short-lived test containers

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* test: port feature-gated tests to pytest

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* test: port sabotage self-test to task test:sabotage

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* fix: create parent directories in put_file

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* test: move structure.yml to tests and remove cst volume leak

container-structure-test left one anonymous volume per test container.
tests/structure.py runs it with --save and removes the new containers
with their volumes afterwards.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* test: remove the Bash suite

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* ci: run only the Python suite in the test job

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* docs: describe the Python test suite

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* test: isolate scenario steps, share helpers, use restore_latest, HEAD dir probe

Scenario fixtures record each step; a failing step fails only the tests
that assert on it. running() and raise_interrupt() live in helpers.py.
put_file probes parent directories with a HEAD request instead of a
get_archive stream. stream_run uses restore_latest and asserts its result.
Docstrings no longer refer to the removed Bash suite.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* test: sabotage check rejects errors and malformed reports

Only <failure> of the expected tests counts as red; errors in them and a
malformed JUnit report exit 2 (invalid) instead of passing or exiting 1.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* test: structure wrapper removes only its own containers

Restrict cleanup to containers of the image under test without the
rbd-test-run label and ignore NotFound.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* build: run all test suites and aggregate the exit code

task test no longer stops at the first failing suite.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* fix: sabotage check treats failed scenario steps as INVALID

StepFailed is no AssertionError any more; sabotage.py counts a JUnit failure
named StepFailed as error, so an expected-red test only counts when its own
assertion fails.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* fix: hard timeout for container-structure-test

CST_TIMEOUT (default 300 s) kills a hanging run; existing cleanup removes the
containers; exit code 124 with a clear message.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* fix: shorten sabotage message for lint

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* fix: handle JUnit failures without message in sabotage check

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 5.5 <noreply@anthropic.com>

tests/structure.py

@@ -0,0 +1,77 @@
+"""Run container-structure-test without leaking Docker volumes.
+
+container-structure-test starts one container per test and never removes it. The image
+declares `VOLUME /data`, so every container drags an anonymous volume along that outlives
+`docker rm`. With `--save` the containers are kept, and this wrapper removes the ones of
+the image under test that the run created, together with their volumes (`remove(v=True)`);
+containers of other images or of the compat suite (a parallel run, a compose stack) are left
+alone.
+Run with `task test:structure`.
+
+A run longer than CST_TIMEOUT seconds (default 300) is killed: container-structure-test has
+no timeout of its own and can block forever waiting for a container.
+
+Exit code: the one of container-structure-test; 124 on timeout.
+"""
+
+from __future__ import annotations
+
+import contextlib
+import os
+import signal
+import subprocess
+import sys
+from pathlib import Path
+
+import docker
+from helpers import raise_interrupt
+
+CONFIG = Path(__file__).with_name("structure.yml")
+TIMEOUT_EXIT = 124
+
+
+def _containers_of(client: docker.DockerClient, image_id: str) -> list:
+    """Containers of the image that container-structure-test could have created.
+
+    Containers of the compat suite carry the `rbd-test-run` label; their owner removes them.
+    """
+    found = client.containers.list(all=True, filters={"ancestor": image_id})
+    return [c for c in found if "rbd-test-run" not in c.labels]
+
+
+def main() -> int:
+    image = os.environ.get("IMAGE", "restic-backup-docker:test")
+    signal.signal(signal.SIGTERM, raise_interrupt)
+    client = docker.from_env()
+    image_id = client.images.get(image).id
+    before = {c.id for c in _containers_of(client, image_id)}
+    try:
+        timeout = float(os.environ.get("CST_TIMEOUT", "300"))
+        try:
+            return subprocess.run(
+                [
+                    "container-structure-test",
+                    "test",
+                    "--save",
+                    "--image",
+                    image,
+                    "--config",
+                    os.environ.get("CST_CONFIG", str(CONFIG)),
+                ],
+                check=False,
+                timeout=timeout,
+            ).returncode
+        except subprocess.TimeoutExpired:
+            print(f"container-structure-test timed out after {timeout:g} s", file=sys.stderr)
+            return TIMEOUT_EXIT
+    finally:
+        signal.signal(signal.SIGINT, signal.SIG_IGN)
+        for container in _containers_of(client, image_id):
+            if container.id not in before:
+                with contextlib.suppress(docker.errors.NotFound):
+                    container.remove(v=True, force=True)
+        signal.signal(signal.SIGINT, signal.default_int_handler)
+
+
+if __name__ == "__main__":
+    sys.exit(main())