Fix generate_asn mask and add unit tests

Change-Id: I18776f026ba288a150e783e4102006e690572d6f

.stestr.conf

@@ -0,0 +1,3 @@
+[DEFAULT]
+test_path=./unit_tests
+top_dir=./

interface.yaml

@@ -2,3 +2,8 @@ name: bgp
 summary: BGP interface
 version: 1
 repo: https://github.com/openstack-charmers/charm-interface-bgp.git
+ignore:
+  - 'unit_tests'
+  - '.stestr.conf'
+  - 'test-requirements.txt'
+  - 'tox.ini'

provides.py

@@ -45,16 +45,13 @@ class BGPEndpoint(reactive.Endpoint):
           4 200 000 000 - 4 211 081 214
         """
         asn_base = 4211081215
-        mask = netaddr.IPAddress('5.255.255.255')
+        mask = netaddr.IPAddress('4.255.255.255')
         unit_ip = netaddr.IPAddress(
                 ch_core.hookenv.unit_get('private-address'))
         masked_ip = unit_ip & mask
 
         asn = asn_base + int(masked_ip)
 
-        # XXX: This assert should be removed from code and put in a unit test
-        assert asn <= 4294967294
-
         return asn
 
     def publish_info(self, asn=None, passive=False, bindings=None):

test-requirements.txt

@@ -0,0 +1,6 @@
+# Lint and unit test requirements
+flake8
+os-testr>=0.4.1
+charms.reactive
+mock>=1.2
+coverage>=3.6

tox.ini

@@ -0,0 +1,23 @@
+[tox]
+skipsdist = True
+envlist = pep8,py35
+
+[testenv]
+setenv = VIRTUAL_ENV={envdir}
+         PYTHONHASHSEED=0
+         TERM=linux
+install_command =
+  pip install {opts} {packages}
+
+[testenv:py35]
+basepython = python3
+deps = -r{toxinidir}/test-requirements.txt
+commands = ostestr {posargs}
+
+[testenv:pep8]
+basepython = python3
+deps = -r{toxinidir}/test-requirements.txt
+commands = flake8 {posargs} . unit_tests
+
+[testenv:venv]
+commands = {posargs}

unit_tests/__init__.py

@@ -0,0 +1,87 @@
+# Copyright 2016 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 sys
+import mock
+
+# mock out some charmhelpers libraries as they have apt install side effects
+apt_pkg = mock.MagicMock()
+charmhelpers = mock.MagicMock()
+sys.modules['apt_pkg'] = apt_pkg
+sys.modules['charmhelpers'] = charmhelpers
+sys.modules['charmhelpers.core'] = charmhelpers.core
+sys.modules['charmhelpers.core.decorators'] = charmhelpers.core.decorators
+sys.modules['charmhelpers.core.hookenv'] = charmhelpers.core.hookenv
+sys.modules['charmhelpers.core.host'] = charmhelpers.core.host
+sys.modules['charmhelpers.core.templating'] = charmhelpers.core.templating
+sys.modules['charmhelpers.core.unitdata'] = charmhelpers.core.unitdata
+sys.modules['charmhelpers.contrib'] = charmhelpers.contrib
+sys.modules['charmhelpers.contrib.openstack'] = charmhelpers.contrib.openstack
+sys.modules['charmhelpers.contrib.openstack.ha'] = (
+    charmhelpers.contrib.openstack.ha)
+sys.modules['charmhelpers.contrib.openstack.utils'] = (
+    charmhelpers.contrib.openstack.utils)
+sys.modules['charmhelpers.contrib.openstack.templating'] = (
+    charmhelpers.contrib.openstack.templating)
+sys.modules['charmhelpers.contrib.openstack.context'] = (
+    charmhelpers.contrib.openstack.context)
+sys.modules['charmhelpers.contrib.network'] = charmhelpers.contrib.network
+sys.modules['charmhelpers.contrib.network.ip'] = (
+    charmhelpers.contrib.network.ip)
+sys.modules['charmhelpers.fetch'] = charmhelpers.fetch
+sys.modules['charmhelpers.cli'] = charmhelpers.cli
+sys.modules['charmhelpers.contrib.hahelpers'] = charmhelpers.contrib.hahelpers
+sys.modules['charmhelpers.contrib.hahelpers.cluster'] = (
+    charmhelpers.contrib.hahelpers.cluster)
+
+# mock in the openstack releases so that the tests can run
+# Note that these don't need to be maintained UNLESS new functionality is for
+# later OpenStack releases.
+charmhelpers.contrib.openstack.utils.OPENSTACK_RELEASES = (
+    'diablo',
+    'essex',
+    'folsom',
+    'grizzly',
+    'havana',
+    'icehouse',
+    'juno',
+    'kilo',
+    'liberty',
+    'mitaka',
+    'newton',
+    'ocata',
+    'pike',
+)
+
+
+def _fake_retry(num_retries, base_delay=0, exc_type=Exception):
+    def _retry_on_exception_inner_1(f):
+        def _retry_on_exception_inner_2(*args, **kwargs):
+            return f(*args, **kwargs)
+        return _retry_on_exception_inner_2
+    return _retry_on_exception_inner_1
+
+
+mock.patch(
+    'charmhelpers.core.decorators.retry_on_exception',
+    _fake_retry).start()
+
+
+def _fake_cached(f):
+    return f
+
+
+mock.patch(
+    'charmhelpers.core.hookenv.cached',
+    _fake_cached).start()

unit_tests/test_provides.py

@@ -0,0 +1,32 @@
+# 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.
+
+import unit_tests.utils as ut_utils
+import provides
+
+
+class TestBGPProvides(ut_utils.BaseTestCase):
+    def test_generate_asn_min(self):
+        self.patch_object(provides, 'ch_core')
+        self.ch_core.hookenv.unit_get.return_value = '0.0.0.0'
+        endpoint = provides.BGPEndpoint('bgpserver')
+        asn = endpoint.generate_asn()
+        self.assertEqual(asn, 4211081215)
+
+    def test_generate_asn_max(self):
+        self.patch_object(provides, 'ch_core')
+        self.ch_core.hookenv.unit_get.return_value = '255.255.255.255'
+        endpoint = provides.BGPEndpoint('bgpserver')
+        asn = endpoint.generate_asn()
+        self.assertEqual(asn, 4294967294)

unit_tests/utils.py

@@ -0,0 +1,82 @@
+# 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.
+
+# Note that the unit_tests/__init__.py also mocks out two charmhelpers imports
+# that have side effects that try to apt install modules:
+# sys.modules['charmhelpers.contrib.openstack.utils'] = mock.MagicMock()
+# sys.modules['charmhelpers.contrib.network.ip'] = mock.MagicMock()
+
+import contextlib
+import io
+import mock
+import unittest
+
+
+@contextlib.contextmanager
+def patch_open():
+    '''Patch open() to allow mocking both open() itself and the file that is
+    yielded.
+
+    Yields the mock for "open" and "file", respectively.'''
+    mock_open = mock.MagicMock(spec=open)
+    mock_file = mock.MagicMock(spec=io.FileIO)
+
+    @contextlib.contextmanager
+    def stub_open(*args, **kwargs):
+        mock_open(*args, **kwargs)
+        yield mock_file
+
+    with mock.patch('builtins.open', stub_open):
+        yield mock_open, mock_file
+
+
+class BaseTestCase(unittest.TestCase):
+
+    def setUp(self):
+        self._patches = {}
+        self._patches_start = {}
+
+    def tearDown(self):
+        for k, v in self._patches.items():
+            v.stop()
+            setattr(self, k, None)
+        self._patches = None
+        self._patches_start = None
+
+    def patch_object(self, obj, attr, return_value=None, name=None, new=None,
+                     **kwargs):
+        if name is None:
+            name = attr
+        if new is not None:
+            mocked = mock.patch.object(obj, attr, new=new, **kwargs)
+        else:
+            mocked = mock.patch.object(obj, attr, **kwargs)
+        self._patches[name] = mocked
+        started = mocked.start()
+        if new is None:
+            started.return_value = return_value
+        self._patches_start[name] = started
+        setattr(self, name, started)
+
+    def patch(self, item, return_value=None, name=None, new=None, **kwargs):
+        if name is None:
+            raise RuntimeError("Must pass 'name' to .patch()")
+        if new is not None:
+            mocked = mock.patch(item, new=new, **kwargs)
+        else:
+            mocked = mock.patch(item, **kwargs)
+        self._patches[name] = mocked
+        started = mocked.start()
+        if new is None:
+            started.return_value = return_value
+        self._patches_start[name] = started
+        setattr(self, name, started)