distros/tests/test_init: add tests for _get_package_mirror_info

cloudinit/distros/tests/test_init.py

@@ -0,0 +1,83 @@
+# Copyright (C) 2020 Canonical Ltd.
+#
+# Author: Daniel Watkins <oddbloke@ubuntu.com>
+#
+# This file is part of cloud-init. See LICENSE file for license information.
+"""Tests for cloudinit/distros/__init__.py"""
+
+from unittest import mock
+
+import pytest
+
+from cloudinit.distros import _get_package_mirror_info
+
+
+class TestGetPackageMirrorInfo:
+    """
+    Tests for cloudinit.distros._get_package_mirror_info.
+
+    These supplement the tests in tests/unittests/test_distros/test_generic.py
+    which are more focused on testing a single production-like configuration.
+    These tests are more focused on specific aspects of the unit under test.
+    """
+
+    @pytest.mark.parametrize('mirror_info,expected', [
+        # Empty info gives empty return
+        ({}, {}),
+        # failsafe values used if present
+        ({'failsafe': {'primary': 'value', 'security': 'other'}},
+         {'primary': 'value', 'security': 'other'}),
+        # search values used if present
+        ({'search': {'primary': ['value'], 'security': ['other']}},
+         {'primary': ['value'], 'security': ['other']}),
+        # failsafe values used if search value not present
+        ({'search': {'primary': ['value']}, 'failsafe': {'security': 'other'}},
+         {'primary': ['value'], 'security': 'other'})
+    ])
+    def test_get_package_mirror_info_failsafe(self, mirror_info, expected):
+        """
+        Test the interaction between search and failsafe inputs
+
+        (This doesn't test the case where the mirror_filter removes all search
+        options; test_failsafe_used_if_all_search_results_filtered_out covers
+        that.)
+        """
+        assert expected == _get_package_mirror_info(mirror_info,
+                                                    mirror_filter=lambda x: x)
+
+    def test_failsafe_used_if_all_search_results_filtered_out(self):
+        """Test the failsafe option used if all search options eliminated."""
+        mirror_info = {
+            'search': {'primary': ['value']}, 'failsafe': {'primary': 'other'}
+        }
+        assert {'primary': 'other'} == _get_package_mirror_info(
+            mirror_info, mirror_filter=lambda x: False)
+
+    @pytest.mark.parametrize('availability_zone,region,patterns,expected', (
+        # Test ec2_region alone
+        ('fk-fake-1f', None, ['EC2-%(ec2_region)s'], ['EC2-fk-fake-1']),
+        # Test availability_zone alone
+        ('fk-fake-1f', None, ['AZ-%(availability_zone)s'], ['AZ-fk-fake-1f']),
+        # Test region alone
+        (None, 'fk-fake-1', ['RG-%(region)s'], ['RG-fk-fake-1']),
+        # Test that ec2_region is not available for non-matching AZs
+        ('fake-fake-1f', None,
+         ['EC2-%(ec2_region)s', 'AZ-%(availability_zone)s'],
+         ['AZ-fake-fake-1f']),
+        # Test that template order maintained
+        (None, 'fake-region', ['RG-%(region)s-2', 'RG-%(region)s-1'],
+         ['RG-fake-region-2', 'RG-fake-region-1']),
+    ))
+    def test_substitution(self, availability_zone, region, patterns, expected):
+        """Test substitution works as expected."""
+        m_data_source = mock.Mock(
+            availability_zone=availability_zone, region=region
+        )
+        mirror_info = {'search': {'primary': patterns}}
+
+        ret = _get_package_mirror_info(
+            mirror_info,
+            data_source=m_data_source,
+            mirror_filter=lambda x: x
+        )
+        assert {'primary': expected} == ret