Improve platform mocking

Patch out charmhelpers.osplatform.get_platform() and
charmhelpers.core.host.lsb_release() globally in the unit tests to
insulate the unit tests from the platform that the unit tests are being
run on.

Change-Id: Ifda8aa2675b4a756109254f62b9a600c42679cac

osci.yaml

@@ -7,8 +7,6 @@
       - jammy-antelope-ec_cinder-ceph
       - jammy-bobcat-ec_cinder-ceph:
           voting: false
-      - lunar-antelope-ec_cinder-ceph:
-          voting: false
       - mantic-bobcat-ec_cinder-ceph:
           voting: false
     vars:
@@ -34,13 +32,6 @@
       - jammy-antelope-ec_cinder-ceph
     vars:
       tox_extra_args: '-- jammy-bobcat-ec'
-- job:
-    name: lunar-antelope-ec_cinder-ceph
-    parent: func-target
-    dependencies:
-      - jammy-antelope-ec_cinder-ceph
-    vars:
-      tox_extra_args: '-- lunar-antelope-ec'
 - job:
     name: mantic-bobcat-ec_cinder-ceph
     parent: func-target

tests/tests.yaml

@@ -14,9 +14,7 @@ gate_bundles:
 dev_bundles:
   - jammy-bobcat-ec
   - jammy-bobcat
-  - lunar-antelope-ec
   - mantic-bobcat-ec
-  - lunar-antelope
   - mantic-bobcat
 
 configure:
@@ -42,7 +40,5 @@ tests_options:
   policyd:
     service: cinder
   force_deploy:
-    - lunar-antelope
     - mantic-bobcat
-    - lunar-antelope-ec
     - mantic-bobcat-ec

unit_tests/__init__.py

@@ -14,6 +14,7 @@
 
 import os
 import sys
+from unittest.mock import patch
 
 _path = os.path.dirname(os.path.realpath(__file__))
 _actions = os.path.abspath(os.path.join(_path, '../actions'))
@@ -31,3 +32,15 @@ _add_path(_actions)
 _add_path(_hooks)
 _add_path(_charmhelpers)
 _add_path(_unit_tests)
+
+# Patch out lsb_release() and get_platform() as unit tests should be fully
+# insulated from the underlying platform.  Unit tests assume that the system is
+# ubuntu jammy.
+patch(
+    'charmhelpers.osplatform.get_platform', return_value='ubuntu'
+).start()
+patch(
+    'charmhelpers.core.host.lsb_release',
+    return_value={
+        'DISTRIB_CODENAME': 'jammy'
+    }).start()