[DPE-3077] Block roles in legacy interface (#302)

* Block if roles are requested

* Unconditionally skip the nextcloud test

* Mangled comment

Author: dragomirp

src/relations/db.py

@@ -31,6 +31,10 @@
     "extensions requested through relation, enable them through config options"
 )
 
+ROLES_BLOCKING_MESSAGE = (
+    "roles requested through relation, use postgresql_client interface instead"
+)
+
 
 class DbProvides(Object):
     """Defines functionality for the 'provides' side of the 'db' relation.
@@ -70,7 +74,7 @@ def __init__(self, charm: CharmBase, admin: bool = False):
         self.charm = charm
 
     def _check_for_blocking_relations(self, relation_id: int) -> bool:
-        """Checks if there are relations with extensions.
+        """Checks if there are relations with extensions or roles.
 
         Args:
             relation_id: current relation to be skipped
@@ -80,7 +84,7 @@ def _check_for_blocking_relations(self, relation_id: int) -> bool:
                 if relation.id == relation_id:
                     continue
                 for data in relation.data.values():
-                    if "extensions" in data:
+                    if "extensions" in data or "roles" in data:
                         return True
         return False
 
@@ -127,6 +131,10 @@ def _get_extensions(self, relation: Relation) -> Tuple[List, Set]:
                     disabled_extensions.add(extension_name)
         return required_extensions, disabled_extensions
 
+    def _get_roles(self, relation: Relation) -> bool:
+        """Checks if relation required roles."""
+        return "roles" in relation.data.get(relation.app, {})
+
     def set_up_relation(self, relation: Relation) -> bool:
         """Set up the relation to be used by the application charm."""
         # Do not allow apps requesting extensions to be installed
@@ -139,6 +147,9 @@ def set_up_relation(self, relation: Relation) -> bool:
             )
             self.charm.unit.status = BlockedStatus(EXTENSIONS_BLOCKING_MESSAGE)
             return False
+        if self._get_roles(relation):
+            self.charm.unit.status = BlockedStatus(ROLES_BLOCKING_MESSAGE)
+            return False
 
         database = relation.data.get(relation.app, {}).get("database")
         if not database:
@@ -261,7 +272,10 @@ def _on_relation_broken(self, event: RelationBrokenEvent) -> None:
 
     def _update_unit_status(self, relation: Relation) -> None:
         """Clean up Blocked status if it's due to extensions request."""
-        if self.charm.is_blocked and self.charm.unit.status.message == EXTENSIONS_BLOCKING_MESSAGE:
+        if self.charm.is_blocked and self.charm.unit.status.message in [
+            EXTENSIONS_BLOCKING_MESSAGE,
+            ROLES_BLOCKING_MESSAGE,
+        ]:
             if not self._check_for_blocking_relations(relation.id):
                 self.charm.unit.status = ActiveStatus()
 

tests/integration/ha_tests/helpers.py

@@ -20,9 +20,8 @@
     wait_fixed,
 )
 
-from ..helpers import db_connect, get_unit_address, run_command_on_unit
+from ..helpers import APPLICATION_NAME, db_connect, get_unit_address, run_command_on_unit
 
-APPLICATION_NAME = "postgresql-test-app"
 METADATA = yaml.safe_load(Path("./metadata.yaml").read_text())
 PORT = 5432
 APP_NAME = METADATA["name"]

tests/integration/ha_tests/test_replication.py

@@ -6,9 +6,8 @@
 from pytest_operator.plugin import OpsTest
 from tenacity import Retrying, stop_after_delay, wait_fixed
 
-from ..helpers import CHARM_SERIES, db_connect, scale_application
+from ..helpers import APPLICATION_NAME, CHARM_SERIES, db_connect, scale_application
 from .helpers import (
-    APPLICATION_NAME,
     app_name,
     are_writes_increasing,
     check_writes,

tests/integration/ha_tests/test_upgrade.py

@@ -12,14 +12,14 @@
 from pytest_operator.plugin import OpsTest
 
 from ..helpers import (
+    APPLICATION_NAME,
     DATABASE_APP_NAME,
     count_switchovers,
     get_leader_unit,
     get_primary,
 )
 from ..new_relations.helpers import get_application_relation_data
 from .helpers import (
-    APPLICATION_NAME,
     are_writes_increasing,
     check_writes,
     start_continuous_writes,

tests/integration/ha_tests/test_upgrade_from_stable.py

@@ -7,14 +7,14 @@
 from pytest_operator.plugin import OpsTest
 
 from ..helpers import (
+    APPLICATION_NAME,
     DATABASE_APP_NAME,
     count_switchovers,
     get_leader_unit,
     get_primary,
     remove_chown_workaround,
 )
 from .helpers import (
-    APPLICATION_NAME,
     are_writes_increasing,
     check_writes,
     start_continuous_writes,

tests/integration/helpers.py

@@ -34,6 +34,7 @@
 METADATA = yaml.safe_load(Path("./metadata.yaml").read_text())
 DATABASE_APP_NAME = METADATA["name"]
 STORAGE_PATH = METADATA["storage"]["pgdata"]["location"]
+APPLICATION_NAME = "postgresql-test-app"
 
 
 async def build_connection_string(

tests/integration/test_db.py

@@ -13,6 +13,7 @@
 
 from . import markers
 from .helpers import (
+    APPLICATION_NAME,
     CHARM_SERIES,
     DATABASE_APP_NAME,
     build_connection_string,
@@ -21,6 +22,7 @@
     deploy_and_relate_application_with_postgresql,
     deploy_and_relate_bundle_with_postgresql,
     find_unit,
+    get_leader_unit,
     run_command_on_unit,
 )
 
@@ -32,6 +34,10 @@
 DATABASE_UNITS = 2
 RELATION_NAME = "db"
 
+ROLES_BLOCKING_MESSAGE = (
+    "roles requested through relation, use postgresql_client interface instead"
+)
+
 
 @pytest.mark.group(1)
 async def test_mailman3_core_db(ops_test: OpsTest, charm: str) -> None:
@@ -173,7 +179,7 @@ async def test_relation_data_is_updated_correctly_when_scaling(ops_test: OpsTest
 
 
 @pytest.mark.group(1)
-@pytest.mark.unstable
+@pytest.mark.skip(reason="Should be ported and moved to the new relation tests")
 async def test_nextcloud_db_blocked(ops_test: OpsTest, charm: str) -> None:
     async with ops_test.fast_forward():
         # Deploy Nextcloud.
@@ -294,6 +300,64 @@ async def test_sentry_db_blocked(ops_test: OpsTest, charm: str) -> None:
         )
 
 
+@pytest.mark.group(1)
+async def test_roles_blocking(ops_test: OpsTest, charm: str) -> None:
+    await ops_test.model.deploy(
+        APPLICATION_NAME,
+        application_name=APPLICATION_NAME,
+        config={"legacy_roles": True},
+        series=CHARM_SERIES,
+        channel="edge",
+    )
+    await ops_test.model.deploy(
+        APPLICATION_NAME,
+        application_name=f"{APPLICATION_NAME}2",
+        config={"legacy_roles": True},
+        series=CHARM_SERIES,
+        channel="edge",
+    )
+
+    await ops_test.model.wait_for_idle(
+        apps=[DATABASE_APP_NAME, APPLICATION_NAME, f"{APPLICATION_NAME}2"],
+        status="active",
+        timeout=1000,
+    )
+
+    await asyncio.gather(
+        ops_test.model.relate(f"{DATABASE_APP_NAME}:db", f"{APPLICATION_NAME}:db"),
+        ops_test.model.relate(f"{DATABASE_APP_NAME}:db", f"{APPLICATION_NAME}2:db"),
+    )
+
+    leader_unit = await get_leader_unit(ops_test, DATABASE_APP_NAME)
+    await ops_test.model.block_until(
+        lambda: leader_unit.workload_status_message == ROLES_BLOCKING_MESSAGE, timeout=1000
+    )
+
+    assert leader_unit.workload_status_message == ROLES_BLOCKING_MESSAGE
+
+    logger.info("Verify that the charm remains blocked if there are other blocking relations")
+    await ops_test.model.applications[DATABASE_APP_NAME].destroy_relation(
+        f"{DATABASE_APP_NAME}:db", f"{APPLICATION_NAME}:db"
+    )
+
+    await ops_test.model.block_until(
+        lambda: leader_unit.workload_status_message == ROLES_BLOCKING_MESSAGE, timeout=1000
+    )
+
+    assert leader_unit.workload_status_message == ROLES_BLOCKING_MESSAGE
+
+    logger.info("Verify that active status is restored when all blocking relations are gone")
+    await ops_test.model.applications[DATABASE_APP_NAME].destroy_relation(
+        f"{DATABASE_APP_NAME}:db", f"{APPLICATION_NAME}2:db"
+    )
+
+    await ops_test.model.wait_for_idle(
+        apps=[DATABASE_APP_NAME],
+        status="active",
+        timeout=1000,
+    )
+
+
 @pytest.mark.group(1)
 @pytest.mark.unstable
 async def test_weebl_db(ops_test: OpsTest, charm: str) -> None: