Resolve 'double' async loop issue with get_app_ips()

Bug [1] indicated a fault in the logic for get_app_ips() where the code
went sync -> async -> sync -> async and thus ended up trying to reuse
the same event loop.

tests-extended/tests.yaml

@@ -28,7 +28,6 @@ tests_options:
           log-to-stdout: false
           log-to-python-logging: true
           python-logging-level: info
-          logger-name: DEFAULT
           raise-exceptions: true
     upload:
       - type: InfluxDB

tests/bundles/first.yaml

@@ -9,4 +9,4 @@ applications:
     num_units: 2
   ubuntu:
     charm: cs:ubuntu
-    num_units: 1
+    num_units: 3

tests/bundles/second.yaml

@@ -9,4 +9,4 @@ applications:
     num_units: 2
   ubuntu:
     charm: cs:ubuntu
-    num_units: 1
+    num_units: 3

tests/tests.yaml

@@ -24,6 +24,7 @@ configure:
 - zaza.charm_tests.noop.setup.basic_setup
 tests:
 - zaza.charm_tests.noop.tests.NoopTest
+- zaza.charm_tests.libjuju.tests.RegressionTest
 tests_options:
   force_deploy:
     first

zaza/charm_tests/libjuju/__init__.py

@@ -0,0 +1,16 @@
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Collection of regression tests checking zaza/libjuju integration."""
+

zaza/charm_tests/libjuju/tests.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python3
+
+# Copyright 2018 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Test regression libjuju / zaza integration."""
+
+import logging
+import unittest
+
+import zaza.model
+
+
+class RegressionTest(unittest.TestCase):
+    """Regression Tests."""
+
+    def test_get_unit_public_address(self):
+        """Verify get_unit_public_address()."""
+        logging.info('Verify that get_unit_public_address() function works.')
+        units = zaza.model.get_units('ubuntu')
+        ips = [zaza.model.get_unit_public_address(unit) for unit in units]
+        for ip in ips:
+            self.assertIsNotNone(ip)
+
+    def test_get_app_ips(self):
+        """Verify that get_app_ips() doesn't invoke to async loops."""
+        logging.info('Verify that get_app_ips() works.')
+        ips = zaza.model.get_app_ips('ubuntu')
+        for ip in ips:
+            self.assertIsNotNone(ip)
+

zaza/model.py

@@ -697,7 +697,8 @@ async def async_get_app_ips(application_name, model_name=None):
     :rtype: [str, str,...]
     """
     return [await u.get_public_address()
-            for u in get_units(application_name, model_name=model_name)]
+            for u in await async_get_units(
+                application_name, model_name=model_name)]
 
 
 get_app_ips = sync_wrapper(async_get_app_ips)