diff --git a/installers/charm/nbi/src/charm.py b/installers/charm/nbi/src/charm.py
index f2b2ecf..848b53d 100755
--- a/installers/charm/nbi/src/charm.py
+++ b/installers/charm/nbi/src/charm.py
@@ -129,10 +129,8 @@
         Args:
             event (EventBase): Kafka relation event.
         """
-        data_loc = event.unit if event.unit else event.app
-
-        message_host = event.relation.data[data_loc].get("host")
-        message_port = event.relation.data[data_loc].get("port")
+        message_host = event.relation.data[event.unit].get("host")
+        message_port = event.relation.data[event.unit].get("port")
 
         if (
             message_host
@@ -162,9 +160,7 @@
         Args:
             event (EventBase): DB relation event.
         """
-        data_loc = event.unit if event.unit else event.app
-
-        database_uri = event.relation.data[data_loc].get("connection_string")
+        database_uri = event.relation.data[event.unit].get("connection_string")
 
         if database_uri and self.state.database_uri != database_uri:
             self.state.database_uri = database_uri
@@ -185,19 +181,17 @@
         Args:
             event (EventBase): Keystone relation event.
         """
-        data_loc = event.unit if event.unit else event.app
-
-        keystone_host = event.relation.data[data_loc].get("host")
-        keystone_port = event.relation.data[data_loc].get("port")
-        keystone_user_domain_name = event.relation.data[data_loc].get(
+        keystone_host = event.relation.data[event.unit].get("host")
+        keystone_port = event.relation.data[event.unit].get("port")
+        keystone_user_domain_name = event.relation.data[event.unit].get(
             "user_domain_name"
         )
-        keystone_project_domain_name = event.relation.data[data_loc].get(
+        keystone_project_domain_name = event.relation.data[event.unit].get(
             "project_domain_name"
         )
-        keystone_username = event.relation.data[data_loc].get("username")
-        keystone_password = event.relation.data[data_loc].get("password")
-        keystone_service = event.relation.data[data_loc].get("service")
+        keystone_username = event.relation.data[event.unit].get("username")
+        keystone_password = event.relation.data[event.unit].get("password")
+        keystone_service = event.relation.data[event.unit].get("service")
 
         if (
             keystone_host
@@ -248,10 +242,8 @@
         Args:
             event (EventBase): Prometheus relation event.
         """
-        data_loc = event.unit if event.unit else event.app
-
-        prometheus_host = event.relation.data[data_loc].get("hostname")
-        prometheus_port = event.relation.data[data_loc].get("port")
+        prometheus_host = event.relation.data[event.unit].get("hostname")
+        prometheus_port = event.relation.data[event.unit].get("port")
 
         if (
             prometheus_host
diff --git a/installers/charm/nbi/src/pod_spec.py b/installers/charm/nbi/src/pod_spec.py
index 96518b9..b6291d4 100644
--- a/installers/charm/nbi/src/pod_spec.py
+++ b/installers/charm/nbi/src/pod_spec.py
@@ -101,7 +101,7 @@
         "database_commonkey": lambda value, _: isinstance(value, str)
         and len(value) > 1,
         "log_level": lambda value, _: isinstance(value, str)
-        and (value == "INFO" or value == "DEBUG"),
+        and value in ("INFO", "DEBUG"),
         "auth_backend": lambda value, _: isinstance(value, str)
         and (value == "internal" or value == "keystone"),
         "site_url": lambda value, _: isinstance(value, str)
diff --git a/installers/charm/nbi/tests/test_charm.py b/installers/charm/nbi/tests/test_charm.py
index 0df8e83..657e89b 100644
--- a/installers/charm/nbi/tests/test_charm.py
+++ b/installers/charm/nbi/tests/test_charm.py
@@ -738,36 +738,6 @@
         self.assertNotIn("keystone", self.harness.charm.unit.status.message)
         self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
 
-    def test_on_kafka_app_relation_changed(self) -> NoReturn:
-        """Test to see if kafka relation is updated."""
-        self.harness.charm.on.start.emit()
-
-        self.assertIsNone(self.harness.charm.state.message_host)
-        self.assertIsNone(self.harness.charm.state.message_port)
-
-        relation_id = self.harness.add_relation("kafka", "kafka")
-        self.harness.add_relation_unit(relation_id, "kafka/0")
-        self.harness.update_relation_data(
-            relation_id, "kafka", {"host": "kafka", "port": 9092}
-        )
-
-        self.assertEqual(self.harness.charm.state.message_host, "kafka")
-        self.assertEqual(self.harness.charm.state.message_port, 9092)
-
-        # Verifying status
-        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
-
-        # Verifying status message
-        self.assertGreater(len(self.harness.charm.unit.status.message), 0)
-        self.assertTrue(
-            self.harness.charm.unit.status.message.startswith("Waiting for ")
-        )
-        self.assertNotIn("kafka", self.harness.charm.unit.status.message)
-        self.assertIn("mongodb", self.harness.charm.unit.status.message)
-        self.assertIn("prometheus", self.harness.charm.unit.status.message)
-        self.assertNotIn("keystone", self.harness.charm.unit.status.message)
-        self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
-
     def test_on_mongodb_unit_relation_changed(self) -> NoReturn:
         """Test to see if mongodb relation is updated."""
         self.harness.charm.on.start.emit()
@@ -796,34 +766,6 @@
         self.assertNotIn("keystone", self.harness.charm.unit.status.message)
         self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
 
-    def test_on_mongodb_app_relation_changed(self) -> NoReturn:
-        """Test to see if mongodb relation is updated."""
-        self.harness.charm.on.start.emit()
-
-        self.assertIsNone(self.harness.charm.state.database_uri)
-
-        relation_id = self.harness.add_relation("mongodb", "mongodb")
-        self.harness.add_relation_unit(relation_id, "mongodb/0")
-        self.harness.update_relation_data(
-            relation_id, "mongodb", {"connection_string": "mongodb://mongo:27017"}
-        )
-
-        self.assertEqual(self.harness.charm.state.database_uri, "mongodb://mongo:27017")
-
-        # Verifying status
-        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
-
-        # Verifying status message
-        self.assertGreater(len(self.harness.charm.unit.status.message), 0)
-        self.assertTrue(
-            self.harness.charm.unit.status.message.startswith("Waiting for ")
-        )
-        self.assertIn("kafka", self.harness.charm.unit.status.message)
-        self.assertNotIn("mongodb", self.harness.charm.unit.status.message)
-        self.assertIn("prometheus", self.harness.charm.unit.status.message)
-        self.assertNotIn("keystone", self.harness.charm.unit.status.message)
-        self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
-
     def test_on_prometheus_unit_relation_changed(self) -> NoReturn:
         """Test to see if prometheus relation is updated."""
         self.harness.charm.on.start.emit()
@@ -854,36 +796,6 @@
         self.assertNotIn("keystone", self.harness.charm.unit.status.message)
         self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
 
-    def test_on_prometheus_app_relation_changed(self) -> NoReturn:
-        """Test to see if prometheus relation is updated."""
-        self.harness.charm.on.start.emit()
-
-        self.assertIsNone(self.harness.charm.state.prometheus_host)
-        self.assertIsNone(self.harness.charm.state.prometheus_port)
-
-        relation_id = self.harness.add_relation("prometheus", "prometheus")
-        self.harness.add_relation_unit(relation_id, "prometheus/0")
-        self.harness.update_relation_data(
-            relation_id, "prometheus", {"hostname": "prometheus", "port": 9090}
-        )
-
-        self.assertEqual(self.harness.charm.state.prometheus_host, "prometheus")
-        self.assertEqual(self.harness.charm.state.prometheus_port, 9090)
-
-        # Verifying status
-        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
-
-        # Verifying status message
-        self.assertGreater(len(self.harness.charm.unit.status.message), 0)
-        self.assertTrue(
-            self.harness.charm.unit.status.message.startswith("Waiting for ")
-        )
-        self.assertIn("kafka", self.harness.charm.unit.status.message)
-        self.assertIn("mongodb", self.harness.charm.unit.status.message)
-        self.assertNotIn("prometheus", self.harness.charm.unit.status.message)
-        self.assertNotIn("keystone", self.harness.charm.unit.status.message)
-        self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
-
     def test_on_keystone_unit_relation_changed(self) -> NoReturn:
         """Test to see if keystone relation is updated."""
         self.harness.update_config({"auth_backend": "keystone"})
@@ -938,60 +850,6 @@
         self.assertNotIn("keystone", self.harness.charm.unit.status.message)
         self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
 
-    def test_on_keystone_app_relation_changed(self) -> NoReturn:
-        """Test to see if keystone relation is updated."""
-        self.harness.update_config({"auth_backend": "keystone"})
-
-        self.harness.charm.on.start.emit()
-
-        self.assertIsNone(self.harness.charm.state.keystone_host)
-        self.assertIsNone(self.harness.charm.state.keystone_port)
-        self.assertIsNone(self.harness.charm.state.keystone_user_domain_name)
-        self.assertIsNone(self.harness.charm.state.keystone_project_domain_name)
-        self.assertIsNone(self.harness.charm.state.keystone_username)
-        self.assertIsNone(self.harness.charm.state.keystone_password)
-        self.assertIsNone(self.harness.charm.state.keystone_service)
-
-        relation_id = self.harness.add_relation("keystone", "keystone")
-        self.harness.add_relation_unit(relation_id, "keystone/0")
-        self.harness.update_relation_data(
-            relation_id,
-            "keystone",
-            {
-                "host": "keystone",
-                "port": 5000,
-                "user_domain_name": "default",
-                "project_domain_name": "default",
-                "username": "nbi",
-                "password": "nbi",
-                "service": "service",
-            },
-        )
-
-        self.assertEqual(self.harness.charm.state.keystone_host, "keystone")
-        self.assertEqual(self.harness.charm.state.keystone_port, 5000)
-        self.assertEqual(self.harness.charm.state.keystone_user_domain_name, "default")
-        self.assertEqual(
-            self.harness.charm.state.keystone_project_domain_name, "default"
-        )
-        self.assertEqual(self.harness.charm.state.keystone_username, "nbi")
-        self.assertEqual(self.harness.charm.state.keystone_password, "nbi")
-        self.assertEqual(self.harness.charm.state.keystone_service, "service")
-
-        # Verifying status
-        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
-
-        # Verifying status message
-        self.assertGreater(len(self.harness.charm.unit.status.message), 0)
-        self.assertTrue(
-            self.harness.charm.unit.status.message.startswith("Waiting for ")
-        )
-        self.assertIn("kafka", self.harness.charm.unit.status.message)
-        self.assertIn("mongodb", self.harness.charm.unit.status.message)
-        self.assertIn("prometheus", self.harness.charm.unit.status.message)
-        self.assertNotIn("keystone", self.harness.charm.unit.status.message)
-        self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
-
     def test_publish_nbi_info(self) -> NoReturn:
         """Test to see if nbi relation is updated."""
         expected_result = {
@@ -1003,7 +861,7 @@
 
         relation_id = self.harness.add_relation("nbi", "ng-ui")
         self.harness.add_relation_unit(relation_id, "ng-ui/0")
-        relation_data = self.harness.get_relation_data(relation_id, "nbi")
+        relation_data = self.harness.get_relation_data(relation_id, "nbi/0")
 
         self.assertDictEqual(expected_result, relation_data)