compute: Add 'server volume update' command

We're not going to expose the ability to swap volumes since that's a
things humans should not generally use. From the API docs [1]:

  When updating volumeId, this API is typically meant to only be used
  as part of a larger orchestrated volume migration operation initiated
  in the block storage service via the os-retype or os-migrate_volume
  volume actions. Direct usage of this API to update volumeId is not
  recommended and may result in needing to hard reboot the server to
  update details within the guest such as block storage serial IDs.
  Furthermore, updating volumeId via this API is only implemented by
  certain compute drivers.

We *do* want users to have the ability to change the delete on
termination behavior though, so that's what we expose.

[1] https://docs.openstack.org/api-ref/compute/?expanded=update-a-volume-attachment-detail#update-a-volume-attachment

Change-Id: I50938e1237b4d298521b26a5f9cb90c018dfebaf
Signed-off-by: Stephen Finucane <sfinucan@redhat.com>

2 files changed, 75 insertions, 8 deletions

diff --git a/openstackclient/compute/v2/server.py b/openstackclient/compute/v2/server.py
index 50299d65..fa27f68c 100644
--- a/openstackclient/compute/v2/server.py
+++ b/openstackclient/compute/v2/server.py
@@ -513,27 +513,27 @@ class AddServerVolume(command.Command):
             '--tag',
             metavar='<tag>',
             help=_(
-                "Tag for the attached volume. "
-                "(Supported by API versions '2.49' - '2.latest')"
+                'Tag for the attached volume '
+                '(supported by --os-compute-api-version 2.49 or above)'
             ),
         )
+        # TODO(stephenfin): These should be called 'delete-on-termination' and
+        # 'preserve-on-termination'
         termination_group = parser.add_mutually_exclusive_group()
         termination_group.add_argument(
             '--enable-delete-on-termination',
             action='store_true',
             help=_(
-                "Specify if the attached volume should be deleted when the "
-                "server is destroyed. "
-                "(Supported by API versions '2.79' - '2.latest')"
+                'Delete the volume when the server is destroyed '
+                '(supported by --os-compute-api-version 2.79 or above)'
             ),
         )
         termination_group.add_argument(
             '--disable-delete-on-termination',
             action='store_true',
             help=_(
-                "Specify if the attached volume should not be deleted when "
-                "the server is destroyed. "
-                "(Supported by API versions '2.79' - '2.latest')"
+                'Do not delete the volume when the server is destroyed '
+                '(supported by --os-compute-api-version 2.79 or above)'
             ),
         )
         return parser
diff --git a/openstackclient/compute/v2/server_volume.py b/openstackclient/compute/v2/server_volume.py
index 8a931ae5..b53c92fe 100644
--- a/openstackclient/compute/v2/server_volume.py
+++ b/openstackclient/compute/v2/server_volume.py
@@ -16,6 +16,7 @@
 
 from novaclient import api_versions
 from osc_lib.command import command
+from osc_lib import exceptions
 from osc_lib import utils
 
 from openstackclient.i18n import _
@@ -71,3 +72,69 @@ class ListServerVolume(command.Lister):
                 ) for s in volumes
             ),
         )
+
+
+class UpdateServerVolume(command.Command):
+    """Update a volume attachment on the server."""
+
+    def get_parser(self, prog_name):
+        parser = super(UpdateServerVolume, self).get_parser(prog_name)
+        parser.add_argument(
+            'server',
+            help=_('Server to update volume for (name or ID)'),
+        )
+        parser.add_argument(
+            'volume',
+            help=_('Volume (ID)'),
+        )
+        termination_group = parser.add_mutually_exclusive_group()
+        termination_group.add_argument(
+            '--delete-on-termination',
+            action='store_true',
+            dest='delete_on_termination',
+            default=None,
+            help=_(
+                'Delete the volume when the server is destroyed '
+                '(supported by --os-compute-api-version 2.85 or above)'
+            ),
+        )
+        termination_group.add_argument(
+            '--preserve-on-termination',
+            action='store_false',
+            dest='delete_on_termination',
+            help=_(
+                'Preserve the volume when the server is destroyed '
+                '(supported by --os-compute-api-version 2.85 or above)'
+            ),
+        )
+        return parser
+
+    def take_action(self, parsed_args):
+
+        compute_client = self.app.client_manager.compute
+
+        if parsed_args.delete_on_termination is not None:
+            if compute_client.api_version < api_versions.APIVersion('2.85'):
+                msg = _(
+                    '--os-compute-api-version 2.85 or greater is required to '
+                    'support the --(no-)delete-on-termination option'
+                )
+                raise exceptions.CommandError(msg)
+
+            server = utils.find_resource(
+                compute_client.servers,
+                parsed_args.server,
+            )
+
+            # NOTE(stephenfin): This may look silly, and that's because it is.
+            # This API was originally used only for the swapping volumes, which
+            # is an internal operation that should only be done by
+            # orchestration software rather than a human. We're not going to
+            # expose that, but we are going to expose the ability to change the
+            # delete on termination behavior.
+            compute_client.volumes.update_server_volume(
+                server.id,
+                parsed_args.volume,
+                parsed_args.volume,
+                delete_on_termination=parsed_args.delete_on_termination,
+            )