Fix change WAL settings fixture (#62)

* Fix error that is raised when calling change WAL settings

* Remove unused import

* Add reformatted file

tests/integration/ha_tests/conftest.py

@@ -13,6 +13,7 @@
     get_postgresql_parameter,
     update_restart_delay,
 )
+from tests.integration.helpers import run_command_on_unit
 
 APPLICATION_NAME = "application"
 
@@ -63,9 +64,12 @@ async def wal_settings(ops_test: OpsTest) -> None:
     initial_min_wal_size = await get_postgresql_parameter(ops_test, "min_wal_size")
     initial_wal_keep_segments = await get_postgresql_parameter(ops_test, "wal_keep_segments")
     yield
-    # Rollback to the initial settings.
     app = await app_name(ops_test)
     for unit in ops_test.model.applications[app].units:
+        # Start Patroni if it was previously stopped.
+        await run_command_on_unit(ops_test, unit.name, "systemctl start patroni")
+
+        # Rollback to the initial settings.
         await change_wal_settings(
             ops_test,
             unit.name,

tests/unit/test_charm.py

@@ -325,7 +325,6 @@ def test_on_start_no_patroni_member(
         patroni,
         _postgresql,
     ):
-
         # Mock the passwords.
         patroni.return_value.member_started = False
         _get_password.return_value = "fake-operator-password"