Add CompareOpenStack class.

The CompareOpenStack class allows the comparison of OpenStack codenames.

(cherry picked from commit 7205e31)
(cherry picked from commit f2ef3ac)
(cherry picked from commit d780c3a)
(cherry picked from commit a1e4522)
(cherry picked from commit ffff12c)

unit_tests/utilities/test_zaza_utilities_os_versions.py

@@ -0,0 +1,32 @@
+# Copyright 2023 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.
+
+
+import unit_tests.utils as ut_utils
+from zaza.openstack.utilities import os_versions
+
+
+class TestOpenStackUtils(ut_utils.BaseTestCase):
+
+    def test_compare_openstack(self):
+        yoga = os_versions.CompareOpenStack('yoga')
+        xena = os_versions.CompareOpenStack('xena')
+        wallaby = os_versions.CompareOpenStack('wallaby')
+        self.assertGreater(yoga, xena)
+        self.assertLess(xena, yoga)
+        self.assertGreaterEqual(xena, xena)
+        self.assertGreaterEqual(yoga, yoga)
+        self.assertGreaterEqual(yoga, wallaby)
+
+        self.assertEqual("CompareOpenStack<xena>", repr(xena))

zaza/openstack/utilities/os_versions.py

@@ -274,3 +274,123 @@
         ('4', 'victoria'),
     ]),
 }
+
+
+UBUNTU_RELEASES = (
+    'lucid',
+    'maverick',
+    'natty',
+    'oneiric',
+    'precise',
+    'quantal',
+    'raring',
+    'saucy',
+    'trusty',
+    'utopic',
+    'vivid',
+    'wily',
+    'xenial',
+    'yakkety',
+    'zesty',
+    'artful',
+    'bionic',
+    'cosmic',
+    'disco',
+    'eoan',
+    'focal',
+    'groovy',
+    'hirsute',
+    'impish',
+    'jammy',
+)
+
+
+class BasicStringComparator(object):
+    """Provides a class that will compare strings from an iterator type object.
+
+    Used to provide > and < comparisons on strings that may not necessarily be
+    alphanumerically ordered.  e.g. OpenStack or Ubuntu releases AFTER the
+    z-wrap.
+    """
+
+    _list = None
+
+    def __init__(self, item):
+        """Do init."""
+        if self._list is None:
+            raise Exception("Must define the _list in the class definition!")
+        try:
+            self.index = self._list.index(item)
+        except Exception:
+            raise KeyError("Item '{}' is not in list '{}'"
+                           .format(item, self._list))
+
+    def __eq__(self, other):
+        """Do equals."""
+        assert isinstance(other, str) or isinstance(other, self.__class__)
+        return self.index == self._list.index(other)
+
+    def __ne__(self, other):
+        """Do not equals."""
+        return not self.__eq__(other)
+
+    def __lt__(self, other):
+        """Do less than."""
+        assert isinstance(other, str) or isinstance(other, self.__class__)
+        return self.index < self._list.index(other)
+
+    def __ge__(self, other):
+        """Do greater than or equal."""
+        return not self.__lt__(other)
+
+    def __gt__(self, other):
+        """Do greater than."""
+        assert isinstance(other, str) or isinstance(other, self.__class__)
+        return self.index > self._list.index(other)
+
+    def __le__(self, other):
+        """Do less than or equals."""
+        return not self.__gt__(other)
+
+    def __repr__(self):
+        """Return the representation of CompareOpenStack."""
+        return "%s<%s>" % (self.__class__.__name__, self._list[self.index])
+
+    def __str__(self):
+        """Give back the item at the index.
+
+        This is so it can be used in comparisons like:
+
+        s_mitaka = CompareOpenStack('mitaka')
+        s_newton = CompareOpenstack('newton')
+
+        assert s_newton > s_mitaka
+
+        :returns: <string>
+        """
+        return self._list[self.index]
+
+
+class CompareHostReleases(BasicStringComparator):
+    """Provide comparisons of Ubuntu releases.
+
+    Use in the form of
+
+    if CompareHostReleases(release) > 'trusty':
+        # do something with mitaka
+    """
+
+    _list = UBUNTU_RELEASES
+
+
+class CompareOpenStack(BasicStringComparator):
+    """Provide comparisons of OpenStack releases.
+
+    Use in the form of
+
+    if CompareOpenStack(release) > 'yoga':
+        # do something
+    """
+
+    _list = list(OPENSTACK_CODENAMES.values())
+