Fix paths for NVMe devices (non-nguid)

Fixed regression introduced by
https://review.opendev.org/c/openstack/os-brick/+/800014, where
connect_volume method returned a list with a single path instead of
just the path.

Closes-Bug: #1945323
Change-Id: I5e5b13dd73ab8d30439de76dd73eb41b763e7f05
(cherry picked from commit dd90bb6356)

os_brick/initiator/connectors/nvmeof.py

@@ -194,7 +194,7 @@ class NVMeOFConnector(base.BaseLinuxConnector):
         path = set(all_nvme_devices) - set(current_nvme_devices)
         if not path:
             raise exception.VolumePathsNotFound()
-        return list(path)
+        return list(path)[0]
 
     @utils.retry(exception.VolumeDeviceNotFound)
     def _get_device_path_by_nguid(self, nguid):
@@ -205,14 +205,14 @@ class NVMeOFConnector(base.BaseLinuxConnector):
         LOG.debug("Try to retrieve symlink to %(device_path)s.",
                   {"device_path": device_path})
         try:
-            paths, _err = self._execute('readlink',
-                                        '-e',
-                                        device_path,
-                                        run_as_root=True,
-                                        root_helper=self._root_helper)
-            if not paths:
+            path, _err = self._execute('readlink',
+                                       '-e',
+                                       device_path,
+                                       run_as_root=True,
+                                       root_helper=self._root_helper)
+            if not path:
                 raise exception.VolumePathsNotFound()
-            return paths.split()[0]
+            return path.rstrip()
         except putils.ProcessExecutionError as e:
             LOG.exception(e)
             raise exception.VolumeDeviceNotFound(device=device_path)

os_brick/tests/initiator/connectors/test_nvmeof.py

@@ -214,6 +214,23 @@ class NVMeOFConnectorTestCase(test_connector.ConnectorTestCase):
                                              root_helper=None,
                                              run_as_root=True)
 
+    @mock.patch.object(nvmeof.NVMeOFConnector, '_get_nvme_devices')
+    def test__get_device_path(self, mock_nvme_devices):
+        mock_nvme_devices.return_value = ['/dev/nvme0n1',
+                                          '/dev/nvme1n1',
+                                          '/dev/nvme0n2']
+        current_devices = ['/dev/nvme0n1', '/dev/nvme0n2']
+        self.assertEqual(self.connector._get_device_path(current_devices),
+                         '/dev/nvme1n1')
+
+    @mock.patch.object(nvmeof.NVMeOFConnector, '_get_nvme_devices')
+    def test__get_device_path_no_new_device(self, mock_nvme_devices):
+        current_devices = ['/dev/nvme0n1', '/dev/nvme0n2']
+        mock_nvme_devices.return_value = current_devices
+        self.assertRaises(exception.VolumePathsNotFound,
+                          self.connector._get_device_path,
+                          current_devices)
+
     @mock.patch.object(nvmeof.NVMeOFConnector, '_execute', autospec=True)
     def test__get_device_path_by_nguid(self, mock_execute):
         mock_execute.return_value = '/dev/nvme0n1\n', None

releasenotes/notes/bug-1945323-4140f5aff3558082.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    NVMe-oF connector `bug #1945323
+    <https://bugs.launchpad.net/os-brick/+bug/1945323>`_ [bugs.launchpad.net]: Fixed a regression
+    where connect_volume returned a list with a single path instead of just the path