add unit tests

lib/charms/mongos/v0/mongos_client_interface.py

@@ -118,7 +118,7 @@ def _on_relation_changed(self, event) -> None:
 
         self.charm.set_external_connectivity(external_connectivity)
         if external_connectivity:
-            self.charm.open_mongos_port
+            self.charm.open_mongos_port()
 
     def remove_connection_info(self) -> None:
         """Sends the URI to the related parent application"""

src/charm.py

@@ -11,7 +11,6 @@
 from pathlib import Path
 
 from typing import Set, List, Optional, Dict
-from exceptions import ApplicationHostNotFoundError
 
 from charms.mongodb.v0.mongodb_secrets import SecretCache
 from charms.mongos.v0.mongos_client_interface import MongosProvider
@@ -25,7 +24,7 @@
 from config import Config
 
 import ops
-from ops.model import BlockedStatus, MaintenanceStatus, WaitingStatus, Relation, Unit
+from ops.model import BlockedStatus, MaintenanceStatus, WaitingStatus, Relation
 from ops.charm import InstallEvent, StartEvent, RelationDepartedEvent
 
 import logging
@@ -355,7 +354,7 @@ def get_mongos_host(self) -> str:
         the client wishes to connect to mongos (inside Juju or outside).
         """
         if self.is_external_client:
-            return self._unit_ip(self.unit)
+            return self._unit_ip
         else:
             return Config.MONGOS_SOCKET_URI_FMT
 
@@ -364,21 +363,7 @@ def _generate_relation_departed_key(rel_id: int) -> str:
         """Generates the relation departed key for a specified relation id."""
         return f"relation_{rel_id}_departed"
 
-    def _unit_ip(self, unit: Unit) -> str:
-        """Returns the ip address of a given unit."""
-        # check if host is current host
-        if unit == self.unit:
-            return str(
-                self.model.get_binding(Config.Relations.PEERS).network.bind_address
-            )
-        # check if host is a peer
-        elif unit in self._peers.data:
-            return str(self._peers.data[unit].get("private-address"))
-        # raise exception if host not found
-        else:
-            raise ApplicationHostNotFoundError
-
-    def open_mongos_port():
+    def open_mongos_port(self):
         try:
             logger.debug("opening tcp port")
             subprocess.check_call(["open-port", "{}/TCP".format(Config.MONGOS_PORT)])
@@ -389,6 +374,11 @@ def open_mongos_port():
     # END: helper functions
 
     # BEGIN: properties
+    @property
+    def _unit_ip(self) -> str:
+        """Returns the ip address of the unit."""
+        return str(self.model.get_binding(Config.Relations.PEERS).network.bind_address)
+
     @property
     def is_external_client(self) -> Optional[str]:
         """Returns the database requested by the hosting application of the subordinate charm."""

tests/unit/test_charm.py

@@ -11,17 +11,21 @@
 from parameterized import parameterized
 from unittest import mock
 
+
 from charms.operator_libs_linux.v1 import snap
 from ops.model import BlockedStatus, WaitingStatus
 from ops.testing import Harness
 
-from charm import MongosOperatorCharm
+from charm import MongosOperatorCharm, subprocess
 
 from .helpers import patch_network_get
 
 from charms.data_platform_libs.v0.data_interfaces import DatabaseRequiresEvents
 
 CLUSTER_ALIAS = "cluster"
+MONGOS_SOCKET_URI_FMT = (
+    "%2Fvar%2Fsnap%2Fcharmed-mongodb%2Fcommon%2Fvar%2Fmongodb-27018.sock"
+)
 
 
 class TestCharm(unittest.TestCase):
@@ -143,3 +147,32 @@ def test_status_shows_mongos_waiting(self):
         self.harness.add_relation("cluster", "config-server")
         self.harness.charm.on.update_status.emit()
         self.assertTrue(isinstance(self.harness.charm.unit.status, WaitingStatus))
+
+    @patch_network_get(private_address="1.1.1.1")
+    def test_mongos_host(self):
+        """TBD."""
+        self.harness.charm.app_peer_data["external-connectivity"] = json.dumps(False)
+        mongos_host = self.harness.charm.get_mongos_host()
+        self.assertEqual(mongos_host, MONGOS_SOCKET_URI_FMT)
+
+        self.harness.charm.app_peer_data["external-connectivity"] = json.dumps(True)
+        mongos_host = self.harness.charm.get_mongos_host()
+        self.assertEqual(mongos_host, "1.1.1.1")
+
+    @patch("subprocess.check_call")
+    def test_set_port(self, _call):
+        """Test verifies operation of set port."""
+        self.harness.charm.open_mongos_port()
+
+        # Make sure the port is opened and the service is started
+        self.assertEqual(_call.call_args_list, [mock.call(["open-port", "27018/TCP"])])
+
+    @patch("subprocess.check_call")
+    def test_set_port_failure(self, _call):
+        """Test verifies that we raise the correct errors when we fail to open a port."""
+        _call.side_effect = subprocess.CalledProcessError(
+            cmd="open-port 27018/TCP", returncode=1
+        )
+
+        with self.assertRaises(subprocess.CalledProcessError):
+            self.harness.charm.open_mongos_port()

tests/unit/test_config_server_lib.py

@@ -31,7 +31,9 @@ def setUp(self):
             # related to duplicated events.
             delattr(DatabaseRequiresEvents, f"{CLUSTER_ALIAS}_database_created")
             delattr(DatabaseRequiresEvents, f"{CLUSTER_ALIAS}_endpoints_changed")
-            delattr(DatabaseRequiresEvents, f"{CLUSTER_ALIAS}_read_only_endpoints_changed")
+            delattr(
+                DatabaseRequiresEvents, f"{CLUSTER_ALIAS}_read_only_endpoints_changed"
+            )
         except AttributeError:
             # Ignore the events not existing before the first test.
             pass