Initial scaling test

tests/integration/ha_tests/test_scaling.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+# Copyright 2023 Canonical Ltd.
+# See LICENSE file for licensing details.
+import logging
+from asyncio import gather
+
+import pytest
+from pytest_operator.plugin import OpsTest
+
+from .. import markers
+from ..helpers import (
+    CHARM_SERIES,
+)
+from .conftest import APPLICATION_NAME
+from .helpers import (
+    app_name,
+    are_writes_increasing,
+    get_primary,
+    start_continuous_writes,
+)
+
+logger = logging.getLogger(__name__)
+
+charm = None
+
+
+@pytest.mark.group(1)
+@markers.juju3
+@pytest.mark.abort_on_fail
+async def test_build_and_deploy(ops_test: OpsTest) -> None:
+    """Build and deploy two PostgreSQL clusters."""
+    # This is a potentially destructive test, so it shouldn't be run against existing clusters
+    charm = await ops_test.build_charm(".")
+    async with ops_test.fast_forward():
+        # Deploy the first cluster with reusable storage
+        await gather(
+            ops_test.model.deploy(
+                charm,
+                num_units=2,
+                series=CHARM_SERIES,
+                config={"profile": "testing"},
+            ),
+            ops_test.model.deploy(
+                APPLICATION_NAME,
+                application_name=APPLICATION_NAME,
+                series=CHARM_SERIES,
+                channel="edge",
+            ),
+        )
+
+        await ops_test.model.wait_for_idle(status="active", timeout=1500)
+
+
+@pytest.mark.group(1)
+@markers.juju3
+async def test_removing_primary(ops_test: OpsTest, continuous_writes) -> None:
+    # Start an application that continuously writes data to the database.
+    app = await app_name(ops_test)
+    await start_continuous_writes(ops_test, app)
+    primary = await get_primary(ops_test, app)
+    await ops_test.model.destroy_unit(primary, force=True, destroy_storage=False, max_wait=1500)
+
+    await ops_test.model.wait_for_idle(status="active", timeout=600)
+
+    await are_writes_increasing(ops_test, primary)