Files
docker-volume-backup/tests/unit/restore/test_cluster_replay.py
Kevin Veen-Birkenbach a0204fd3ea feat(restore): replay pg_dumpall cluster dumps
A databases.csv row asking for every database of an instance
(database = '*') makes the backup side write <instance>.cluster.backup.sql
via pg_dumpall, and nothing could read it back: the restore CLI knew
files, postgres and mariadb. That dump was stored and unrestorable - a
format whose producer had no consumer.

Adds `baudolo-restore cluster`. Three properties of a cluster stream
shape it, and each one bit during development:

- It recreates databases, and CREATE DATABASE cannot run inside a
  transaction block. So unlike the single-database replay this one must
  NOT be wrapped in --single-transaction. The unit tests now pin both
  contracts against each other.
- It recreates every role including the one the replay connects as, and
  the pre-clean cannot drop the role holding its own session. That
  single CREATE ROLE is filtered out of the stream while its ALTER ROLE
  is kept, because that is what carries the attributes and the password.
  Found by running it: the first replay died on `role "postgres"
  already exists`.
- --empty means more than for one database: the cluster's databases go
  first, then DROP OWNED BY releases what a role still holds in the
  control database, then the roles themselves. The order is pinned by a
  phase column because \gexec would otherwise emit them interleaved, and
  a role cannot be dropped while it still owns a database.

Without --empty the replay stops at the first object that already
exists. Recreating a cluster over a populated one is a decision, not a
default.

The e2e test drills the real thing: two databases and their owning role
are dropped outright and have to come back with their payload and their
ownership intact.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-17 04:19:03 +02:00

125 lines
5.0 KiB
Python

import tempfile
import unittest
from unittest.mock import MagicMock, patch
from baudolo.restore.db import cluster as cluster_mod
from baudolo.restore.paths import BackupPaths
class TestClusterReplay(unittest.TestCase):
def _replay(self, *, empty: bool):
calls = []
def _capture(container, argv, **kwargs):
calls.append((argv, kwargs.get("stdin")))
return MagicMock()
with tempfile.NamedTemporaryFile(suffix=".sql") as sql:
sql.write(b"CREATE ROLE app;\nCREATE DATABASE app OWNER app;\n")
sql.flush()
with patch.object(cluster_mod, "docker_exec", side_effect=_capture):
cluster_mod.restore_cluster_sql(
container="db",
user="postgres",
password="pw",
sql_path=sql.name,
empty=empty,
)
return calls
def test_the_replay_is_not_wrapped_in_a_transaction(self) -> None:
argv, _ = self._replay(empty=False)[0]
self.assertNotIn(
"--single-transaction",
argv,
"CREATE DATABASE cannot run inside a transaction block, so unlike the "
"single-database replay this stream must not be wrapped in one",
)
self.assertIn("ON_ERROR_STOP=1", argv)
def test_the_replay_targets_the_control_database(self) -> None:
argv, _ = self._replay(empty=False)[0]
self.assertEqual(argv[argv.index("-d") + 1], cluster_mod.CONTROL_DB)
self.assertEqual(argv[argv.index("-U") + 1], "postgres")
def test_without_empty_nothing_is_dropped_first(self) -> None:
self.assertEqual(len(self._replay(empty=False)), 1)
def test_empty_drops_databases_before_their_owners(self) -> None:
calls = self._replay(empty=True)
self.assertEqual(len(calls), 2, f"expected pre-clean + replay: {calls}")
preclean = calls[0][1].decode()
self.assertLess(
preclean.index("DROP DATABASE"),
preclean.index("DROP ROLE"),
"a role cannot be dropped while it still owns a database",
)
self.assertIn("DROP OWNED BY", preclean)
self.assertIn("ORDER BY phase", preclean)
def test_the_preclean_spares_what_the_dump_does_not_recreate(self) -> None:
preclean = self._replay(empty=True)[0][1].decode()
self.assertIn("NOT datistemplate", preclean)
self.assertIn("datname <> current_database()", preclean)
self.assertIn("starts_with(rolname, 'pg_')", preclean)
self.assertIn("rolname <> current_user", preclean)
def test_only_the_connecting_role_loses_its_create(self) -> None:
# Captured from pg_dumpall 17: the bootstrap superuser is recreated like
# any other role, and the pre-clean cannot drop the one holding the
# session - so that single CREATE always collides while its ALTER, which
# carries the attributes and the password, must survive.
dump = [
b"CREATE ROLE app;\n",
b"ALTER ROLE app WITH NOSUPERUSER INHERIT LOGIN PASSWORD 'SCRAM-SHA-256$...';\n",
b"CREATE ROLE postgres;\n",
b"ALTER ROLE postgres WITH SUPERUSER INHERIT LOGIN PASSWORD 'SCRAM-SHA-256$...';\n",
b'CREATE ROLE "odd-name";\n',
]
kept = list(cluster_mod.filter_own_role_creation(dump, "postgres"))
self.assertNotIn(b"CREATE ROLE postgres;\n", kept)
self.assertIn(b"CREATE ROLE app;\n", kept)
self.assertIn(b'CREATE ROLE "odd-name";\n', kept)
self.assertEqual(
sum(1 for line in kept if line.startswith(b"ALTER ROLE postgres")),
1,
"the ALTER re-applies the superuser's attributes and password",
)
def test_a_quoted_connecting_role_is_matched_too(self) -> None:
kept = list(
cluster_mod.filter_own_role_creation(
[b'CREATE ROLE "odd-name";\n'], "odd-name"
)
)
self.assertEqual(kept, [])
def test_a_role_whose_name_merely_starts_the_same_is_kept(self) -> None:
kept = list(
cluster_mod.filter_own_role_creation(
[b"CREATE ROLE postgresql;\n"], "postgres"
)
)
self.assertEqual(kept, [b"CREATE ROLE postgresql;\n"])
def test_a_missing_dump_is_reported_as_such(self) -> None:
with self.assertRaises(FileNotFoundError):
cluster_mod.restore_cluster_sql(
container="db",
user="postgres",
password="pw",
sql_path="/nonexistent/x.cluster.backup.sql",
empty=False,
)
def test_the_path_helper_names_the_dumpall_file(self) -> None:
paths = BackupPaths("vol", "hash", "v1", repo_name="repo", backups_dir="/B")
self.assertEqual(
paths.cluster_file("bigbluebutton"),
"/B/hash/repo/v1/vol/sql/bigbluebutton.cluster.backup.sql",
)
if __name__ == "__main__":
unittest.main()