Add BaseCephClientCharm class

Add BaseCephClientCharm class for charms that act as a ceph
client to inherit.

Depends-On: Ib40fa3b46cc629d5b3e5b199a70cff22451661ee
Change-Id: Id04426c564b9413d50c5c28a49bce9511142a801

ops_openstack/core.py

@@ -1,3 +1,17 @@
+# Copyright 2020 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.
+
 from ops.charm import CharmBase
 from ops.framework import (
     StoredState,

ops_openstack/plugins/classes.py

@@ -0,0 +1,55 @@
+# Copyright 2020 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 ops_openstack.core
+# ch_context needed for bluestore validation
+import charmhelpers.contrib.openstack.context as ch_context
+from ops.model import (
+    ActiveStatus,
+    BlockedStatus,
+)
+
+
+class BaseCephClientCharm(ops_openstack.core.OSBaseCharm):
+
+    def __init__(self, framework):
+        super().__init__(framework)
+        super().register_status_check(self.check_bluestore_compression)
+
+    def check_bluestore_compression(self):
+        try:
+            self.get_bluestore_compression()
+            return ActiveStatus()
+        except ValueError as e:
+            return BlockedStatus(
+                'Invalid configuration: {}'.format(str(e)))
+
+    @staticmethod
+    def get_bluestore_compression():
+        """Get BlueStore Compression charm configuration if present.
+
+        :returns: Dictionary of options suitable for passing on as keyword
+                  arguments or None.
+        :rtype: Optional[Dict[str,any]]
+        :raises: ValueError
+        """
+        try:
+            bluestore_compression = (
+                ch_context.CephBlueStoreCompressionContext())
+            bluestore_compression.validate()
+        except KeyError:
+            # The charm does not have BlueStore Compression options defined
+            bluestore_compression = None
+        if bluestore_compression:
+            return bluestore_compression.get_kwargs()

test-requirements.txt

@@ -5,5 +5,6 @@ mock>=1.2
 coverage>=3.6
 # Install netifaces as its a horrible charmhelpers lazy import
 netifaces
+psutil
 charmhelpers
 git+https://github.com/canonical/operator.git#egg=ops

unit_tests/test_plugins_classes.py

@@ -0,0 +1,105 @@
+# Copyright 2020 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 unittest
+
+from mock import patch
+
+from ops.testing import Harness
+from ops.model import (
+    ActiveStatus,
+    BlockedStatus,
+)
+
+import ops_openstack.plugins.classes
+
+
+class CephTestCharm(ops_openstack.plugins.classes.BaseCephClientCharm):
+    pass
+
+
+class CharmTestCase(unittest.TestCase):
+
+    def setUp(self, obj, patches):
+        super().setUp()
+        self.patches = patches
+        self.obj = obj
+        self.patch_all()
+
+    def patch(self, method):
+        _m = patch.object(self.obj, method)
+        mock = _m.start()
+        self.addCleanup(_m.stop)
+        return mock
+
+    def patch_all(self):
+        for method in self.patches:
+            setattr(self, method, self.patch(method))
+
+
+class TestBaseCephClientCharm(CharmTestCase):
+
+    PATCHES = [
+        'ch_context']
+
+    def setUp(self):
+        super().setUp(ops_openstack.plugins.classes, self.PATCHES)
+        self.harness = Harness(
+            CephTestCharm,
+            meta='''
+                name: client
+                requires:
+                  shared-db:
+                    interface: mysql-shared
+                provides:
+                  ceph-client:
+                    interface: ceph-client
+            ''',
+            actions='''
+                pause:
+                    description: pause action
+                resume:
+                    description: resume action
+            ''')
+        self.harness.add_relation('shared-db', 'mysql')
+
+    def test_update_status(self):
+        self.harness.begin()
+        self.harness.charm._stored.is_started = True
+        self.harness.charm.on.update_status.emit()
+        self.assertEqual(
+            self.harness.charm.unit.status.message,
+            'Unit is ready')
+        self.assertIsInstance(
+            self.harness.charm.unit.status,
+            ActiveStatus)
+
+    def test_update_status_invalid_config(self):
+
+        class BlueCtxt():
+
+            def validate(self):
+                raise ValueError('BadKey')
+
+        self.ch_context.CephBlueStoreCompressionContext = BlueCtxt
+
+        self.harness.begin()
+        self.harness.charm._stored.is_started = True
+        self.harness.charm.on.update_status.emit()
+        self.assertEqual(
+            self.harness.charm.unit.status.message,
+            'Invalid configuration: BadKey')
+        self.assertIsInstance(
+            self.harness.charm.unit.status,
+            BlockedStatus)