fix(backup,restore): harden the branch fixes and prove them with tests

Backup: a container that vanishes between the docker ps listing and the
swarm-task inspect (--rm one-shots, task-history GC) no longer aborts the
whole backup run; it counts as not stoppable and is skipped.

Restore: the postgres replay streams the dump through a spooled temp file
instead of buffering it three times in memory (multi-GB dumps OOMed the
restore mid-replay), and the superuser-only line filter is COPY-aware: data
rows inside COPY ... FROM stdin blocks pass through untouched, so a row
that happens to start with COMMENT ON EXTENSION or ALTER DEFAULT PRIVILEGES
is no longer silently dropped.

The e2e runner talks to the DinD daemon through docker exec instead of a
host-published tcp://127.0.0.1:2375: port publishing is unreachable from
sandboxed runners and from hosts with broken loopback publishing, and the
unencrypted root API port disappears from the host. The debug tmp dump
shrinks to tar plus docker cp against the DinD container itself.

New coverage: an e2e reproducing the swarm flake end to end (service task
on the volume, nothing whitelisted: the backup must succeed, the very same
task container must keep running, and the service must never replace a
task), unit tests for the COPY-aware filter, the swarm-task probe including
the vanished-container path, filter_stoppable ordering, and the one-session
FOREIGN_KEY_CHECKS drop assembly. Full suite: 35 unit, 9 integration,
30 e2e green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/e2e/test_e2e_swarm_task_skip.py

@@ -0,0 +1,196 @@
+# tests/e2e/test_e2e_swarm_task_skip.py
+#
+# Reproduces the swarm flake fixed on this branch: baudolo used to stop a
+# swarm task container around the volume file backup because its image was
+# not whitelisted; the orchestrator immediately replaced the stopped task and
+# the later `docker start` failed on the detached overlay network, killing
+# the backup run. With the fix the task container is skipped (backed up hot):
+# the backup succeeds, the very same container instance keeps running, and
+# the service never has to replace a task.
+import time
+import unittest
+
+from .helpers import (
+    backup_path,
+    backup_run,
+    create_minimal_compose_dir,
+    ensure_empty_dir,
+    latest_version_dir,
+    require_docker,
+    run,
+    unique,
+    write_databases_csv,
+)
+
+
+def _swarm_state() -> str:
+    return run(
+        ["docker", "info", "--format", "{{.Swarm.LocalNodeState}}"]
+    ).stdout.strip()
+
+
+def _task_container_id(service: str, timeout_s: int = 60) -> str:
+    deadline = time.time() + timeout_s
+    while time.time() < deadline:
+        out = run(
+            [
+                "docker",
+                "ps",
+                "--filter",
+                f"label=com.docker.swarm.service.name={service}",
+                "--format",
+                "{{.ID}}",
+            ]
+        ).stdout.strip()
+        if out:
+            return out.splitlines()[0]
+        time.sleep(2)
+    raise RuntimeError(f"No running task container for service {service}")
+
+
+def _started_at(container_id: str) -> str:
+    return run(
+        ["docker", "inspect", "--format", "{{.State.StartedAt}}", container_id]
+    ).stdout.strip()
+
+
+class TestE2ESwarmTaskSkip(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls) -> None:
+        require_docker()
+        cls.prefix = unique("baudolo-e2e-swarm-skip")
+        cls.backups_dir = f"/tmp/{cls.prefix}/Backups"
+        ensure_empty_dir(cls.backups_dir)
+        cls.compose_dir = create_minimal_compose_dir(f"/tmp/{cls.prefix}")
+        cls.repo_name = cls.prefix
+
+        cls.swarm_initted = False
+        if _swarm_state() != "active":
+            run(["docker", "swarm", "init", "--advertise-addr", "127.0.0.1"])
+            cls.swarm_initted = True
+
+        cls.volume = f"{cls.prefix}-vol"
+        cls.service = f"{cls.prefix}-svc"
+        cls.volumes = [cls.volume]
+
+        run(["docker", "volume", "create", cls.volume])
+        run(
+            [
+                "docker",
+                "run",
+                "--rm",
+                "-v",
+                f"{cls.volume}:/data",
+                "alpine:3.20",
+                "sh",
+                "-lc",
+                "echo 'swarm-payload' > /data/payload.txt",
+            ]
+        )
+
+        run(
+            [
+                "docker",
+                "service",
+                "create",
+                "--name",
+                cls.service,
+                "--replicas",
+                "1",
+                "--mount",
+                f"type=volume,source={cls.volume},target=/data",
+                "alpine:3.20",
+                "sleep",
+                "3600",
+            ]
+        )
+        cls.task_cid = _task_container_id(cls.service)
+        cls.task_started_at = _started_at(cls.task_cid)
+
+        cls.databases_csv = f"/tmp/{cls.prefix}/databases.csv"
+        write_databases_csv(cls.databases_csv, [])
+
+        # Whitelist that matches nothing: on main this forces a stop of every
+        # container at the volume, i.e. exactly the flake; on this branch the
+        # swarm task must be skipped instead. (An empty list would leave the
+        # --images-no-stop-required flag without arguments and argparse-fail.)
+        backup_run(
+            backups_dir=cls.backups_dir,
+            repo_name=cls.repo_name,
+            compose_dir=cls.compose_dir,
+            databases_csv=cls.databases_csv,
+            database_containers=["dummy-db"],
+            images_no_stop_required=["image-that-matches-nothing"],
+        )
+        cls.hash, cls.version = latest_version_dir(cls.backups_dir, cls.repo_name)
+
+    @classmethod
+    def tearDownClass(cls) -> None:
+        run(["docker", "service", "rm", cls.service], check=False)
+        deadline = time.time() + 30
+        while time.time() < deadline:
+            out = run(
+                [
+                    "docker",
+                    "ps",
+                    "-aq",
+                    "--filter",
+                    f"label=com.docker.swarm.service.name={cls.service}",
+                ],
+                check=False,
+            ).stdout.strip()
+            if not out:
+                break
+            time.sleep(2)
+        for v in cls.volumes:
+            run(["docker", "volume", "rm", "-f", v], check=False)
+        if cls.swarm_initted:
+            run(["docker", "swarm", "leave", "--force"], check=False)
+
+    def test_volume_backed_up_hot(self) -> None:
+        p = (
+            backup_path(
+                self.backups_dir,
+                self.repo_name,
+                self.version,
+                self.volume,
+            )
+            / "files"
+            / "payload.txt"
+        )
+        self.assertTrue(p.is_file(), f"Expected backed up file at: {p}")
+
+    def test_task_container_never_stopped(self) -> None:
+        out = run(
+            ["docker", "ps", "-q", "--no-trunc", "--filter", f"id={self.task_cid}"]
+        ).stdout.strip()
+        self.assertTrue(
+            out.startswith(self.task_cid) or self.task_cid.startswith(out.strip()[:12]),
+            f"Task container {self.task_cid} is no longer running",
+        )
+        self.assertEqual(
+            self.task_started_at,
+            _started_at(self.task_cid),
+            "Task container was restarted during the backup",
+        )
+
+    def test_service_never_replaced_the_task(self) -> None:
+        states = run(
+            [
+                "docker",
+                "service",
+                "ps",
+                self.service,
+                "--format",
+                "{{.DesiredState}} {{.CurrentState}}",
+            ]
+        ).stdout.strip()
+        lines = [line for line in states.splitlines() if line.strip()]
+        self.assertEqual(
+            len(lines), 1, f"Service task history shows replacements:\n{states}"
+        )
+        self.assertIn("Running", lines[0])
+
+
+if __name__ == "__main__":
+    unittest.main()