Add volume backend capability show command

Adds and equivalend for "cinder get-capabilities" command to show the
capabilities supported by a Cinder backend.

Story: 1655624
Task: 26947

Change-Id: I38686a26cd503e45ce0102705a6632994ef10274
Signed-off-by: Sean McGinnis <sean.mcginnis@gmail.com>

8 files changed, 214 insertions, 1 deletions

diff --git a/doc/source/cli/command-objects/volume-backend.rst b/doc/source/cli/command-objects/volume-backend.rst
new file mode 100644
index 00000000..0285d61b
--- /dev/null
+++ b/doc/source/cli/command-objects/volume-backend.rst
@@ -0,0 +1,8 @@
+==============
+volume backend
+==============
+
+Volume v2
+
+.. autoprogram-cliff:: openstack.volume.v2
+   :command: volume backend *
diff --git a/doc/source/cli/commands.rst b/doc/source/cli/commands.rst
index 76126a74..1ca674d5 100644
--- a/doc/source/cli/commands.rst
+++ b/doc/source/cli/commands.rst
@@ -156,6 +156,7 @@ referring to both Compute and Volume quotas.
 * ``user role``: (**Identity**) roles assigned to a user
 * ``volume``: (**Volume**) block volumes
 * ``volume backup``: (**Volume**) backup for volumes
+* ``volume backend``: (**volume**) volume backend storage
 * ``volume host``: (**Volume**) the physical computer for volumes
 * ``volume qos``: (**Volume**) quality-of-service (QoS) specification for volumes
 * ``volume snapshot``: (**Volume**) a point-in-time copy of a volume
diff --git a/doc/source/cli/data/cinder.csv b/doc/source/cli/data/cinder.csv
index 5c89e086..068ffb7f 100644
--- a/doc/source/cli/data/cinder.csv
+++ b/doc/source/cli/data/cinder.csv
@@ -32,7 +32,7 @@ extra-specs-list,volume type list --long,Lists current volume types and extra sp
 failover-host,volume host failover,Failover a replicating cinder-volume host.

 force-delete,volume delete --force,"Attempts force-delete of volume, regardless of state."

 freeze-host,volume host set --disable,Freeze and disable the specified cinder-volume host.

-get-capabilities,,Show backend volume stats and properties. Admin only.

+get-capabilities,volume backend capability show,Show capabilities of a volume backend. Admin only.

 get-pools,,Show pool information for backends. Admin only.

 image-metadata,volume set --image-property,Sets or deletes volume image metadata.

 image-metadata-show,volume show,Shows volume image metadata.

diff --git a/openstackclient/tests/unit/volume/v2/fakes.py b/openstackclient/tests/unit/volume/v2/fakes.py
index 481509f3..ad13f1b9 100644
--- a/openstackclient/tests/unit/volume/v2/fakes.py
+++ b/openstackclient/tests/unit/volume/v2/fakes.py
@@ -193,6 +193,65 @@ class FakeService(object):
         return services
 
 
+class FakeCapability(object):
+    """Fake capability."""
+
+    @staticmethod
+    def create_one_capability(attrs=None):
+        """Create a fake volume backend capability.
+
+        :param Dictionary attrs:
+            A dictionary with all attributes of the Capabilities.
+        :return:
+            A FakeResource object with capability name and attrs.
+        """
+        # Set default attribute
+        capability_info = {
+            "namespace": "OS::Storage::Capabilities::fake",
+            "vendor_name": "OpenStack",
+            "volume_backend_name": "lvmdriver-1",
+            "pool_name": "pool",
+            "driver_version": "2.0.0",
+            "storage_protocol": "iSCSI",
+            "display_name": "Capabilities of Cinder LVM driver",
+            "description": "Blah, blah.",
+            "visibility": "public",
+            "replication_targets": [],
+            "properties": {
+                "compression": {
+                    "title": "Compression",
+                    "description": "Enables compression.",
+                    "type": "boolean"
+                },
+                "qos": {
+                    "title": "QoS",
+                    "description": "Enables QoS.",
+                    "type": "boolean"
+                },
+                "replication": {
+                    "title": "Replication",
+                    "description": "Enables replication.",
+                    "type": "boolean"
+                },
+                "thin_provisioning": {
+                    "title": "Thin Provisioning",
+                    "description": "Sets thin provisioning.",
+                    "type": "boolean"
+                }
+            }
+        }
+
+        # Overwrite default attributes if there are some attributes set
+        capability_info.update(attrs or {})
+
+        capability = fakes.FakeResource(
+            None,
+            capability_info,
+            loaded=True)
+
+        return capability
+
+
 class FakeVolumeClient(object):
 
     def __init__(self, **kwargs):
@@ -233,6 +292,8 @@ class FakeVolumeClient(object):
         self.cgsnapshots.resource_class = fakes.FakeResource(None, {})
         self.auth_token = kwargs['token']
         self.management_url = kwargs['endpoint']
+        self.capabilities = mock.Mock()
+        self.capabilities.resource_class = fakes.FakeResource(None, {})
 
 
 class TestVolume(utils.TestCommand):
diff --git a/openstackclient/tests/unit/volume/v2/test_volume_backend.py b/openstackclient/tests/unit/volume/v2/test_volume_backend.py
new file mode 100644
index 00000000..73df6032
--- /dev/null
+++ b/openstackclient/tests/unit/volume/v2/test_volume_backend.py
@@ -0,0 +1,73 @@
+#
+#   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 openstackclient.tests.unit.volume.v2 import fakes as volume_fakes
+from openstackclient.volume.v2 import volume_backend
+
+
+class TestShowVolumeCapability(volume_fakes.TestVolume):
+    """Test backend capability functionality."""
+
+    # The capability to be listed
+    capability = volume_fakes.FakeCapability.create_one_capability()
+
+    def setUp(self):
+        super(TestShowVolumeCapability, self).setUp()
+
+        # Get a shortcut to the capability Mock
+        self.capability_mock = self.app.client_manager.volume.capabilities
+        self.capability_mock.get.return_value = self.capability
+
+        # Get the command object to test
+        self.cmd = volume_backend.ShowCapability(self.app, None)
+
+    def test_capability_show(self):
+        arglist = [
+            'fake',
+        ]
+        verifylist = [
+            ('host', 'fake'),
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        # In base command class Lister in cliff, abstract method take_action()
+        # returns a tuple containing the column names and an iterable
+        # containing the data to be listed.
+        columns, data = self.cmd.take_action(parsed_args)
+
+        expected_columns = [
+            'Title',
+            'Key',
+            'Type',
+            'Description',
+        ]
+
+        # confirming if all expected columns are present in the result.
+        self.assertEqual(expected_columns, columns)
+
+        capabilities = [
+            'Compression',
+            'Replication',
+            'QoS',
+            'Thin Provisioning',
+        ]
+
+        # confirming if all expected values are present in the result.
+        for cap in data:
+            self.assertTrue(cap[0] in capabilities)
+
+        # checking if proper call was made to get capabilities
+        self.capability_mock.get.assert_called_with(
+            'fake',
+        )
diff --git a/openstackclient/volume/v2/volume_backend.py b/openstackclient/volume/v2/volume_backend.py
new file mode 100644
index 00000000..0dff18c9
--- /dev/null
+++ b/openstackclient/volume/v2/volume_backend.py
@@ -0,0 +1,61 @@
+#
+#   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.
+#
+
+"""Capability action implementations"""
+
+from osc_lib.command import command
+from osc_lib import utils
+
+from openstackclient.i18n import _
+
+
+class ShowCapability(command.Lister):
+    _description = _("Show capability command")
+
+    def get_parser(self, prog_name):
+        parser = super(ShowCapability, self).get_parser(prog_name)
+        parser.add_argument(
+            "host",
+            metavar="<host>",
+            help=_("List capabilities of specified host (host@backend-name)")
+        )
+        return parser
+
+    def take_action(self, parsed_args):
+        volume_client = self.app.client_manager.volume
+
+        columns = [
+            'Title',
+            'Key',
+            'Type',
+            'Description',
+        ]
+
+        data = volume_client.capabilities.get(parsed_args.host)
+
+        # The get capabilities API is... interesting. We only want the names of
+        # the capabilities that can set for a backend through extra specs, so
+        # we need to extract out that part of the mess that is returned.
+        print_data = []
+        keys = data.properties
+        for key in keys:
+            # Stuff the key into the details to make it easier to output
+            capability_data = data.properties[key]
+            capability_data['key'] = key
+            print_data.append(capability_data)
+
+        return (columns,
+                (utils.get_dict_properties(
+                    s, columns,
+                ) for s in print_data))
diff --git a/releasenotes/notes/volume-backend-c5faae0b31556a24.yaml b/releasenotes/notes/volume-backend-c5faae0b31556a24.yaml
new file mode 100644
index 00000000..851ab2de
--- /dev/null
+++ b/releasenotes/notes/volume-backend-c5faae0b31556a24.yaml
@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    A new command, ``openstack volume backend capability show <host>`` was
+    added which will provide a list of all capabilities that can be configured
+    for the requested backend. The required `<host>` parameter takes the form
+    `host@backend-name`.
diff --git a/setup.cfg b/setup.cfg
index d9ca47ca..888e259b 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -629,6 +629,8 @@ openstack.volume.v2 =
     volume_backup_set = openstackclient.volume.v2.backup:SetVolumeBackup
     volume_backup_show = openstackclient.volume.v2.backup:ShowVolumeBackup
 
+    volume_backend_capability_show = openstackclient.volume.v2.volume_backend:ShowCapability
+
     volume_host_failover = openstackclient.volume.v2.volume_host:FailoverVolumeHost
     volume_host_set = openstackclient.volume.v2.volume_host:SetVolumeHost