Use last digit to determine paritition naming scheme

This matches the behaviour of the linux kernel, see:

d3511f53bb/block/partition-generic.c (L39)

Change-Id: Ic3963e5c4a1886aeabed6c5994599e72040a251e
Story: 2006154
Task: 35656

ironic_lib/disk_utils.py

@@ -201,9 +201,11 @@ def is_iscsi_device(dev, node_uuid):
     return iscsi_id in dev
 
 
-def is_nvme_device(dev):
-    """check whether the device path belongs to an NVMe drive. """
-    return "/dev/nvme" in dev
+def is_last_char_digit(dev):
+    """check whether device name ends with a digit"""
+    if len(dev) >= 1:
+        return dev[-1].isdigit()
+    return False
 
 
 def make_partitions(dev, root_mb, swap_mb, ephemeral_mb,
@@ -251,7 +253,7 @@ def make_partitions(dev, root_mb, swap_mb, ephemeral_mb,
     # the device partitions as /dev/sda1 and not /dev/sda-part1.
     if is_iscsi_device(dev, node_uuid):
         part_template = dev + '-part%d'
-    elif is_nvme_device(dev):
+    elif is_last_char_digit(dev):
         part_template = dev + 'p%d'
     else:
         part_template = dev + '%d'
@@ -941,7 +943,7 @@ def create_config_drive_partition(node_uuid, device, configdrive):
 
             if is_iscsi_device(device, node_uuid):
                 config_drive_part = '%s-part%s' % (device, new_part.pop())
-            elif is_nvme_device(device):
+            elif is_last_char_digit(device):
                 config_drive_part = '%sp%s' % (device, new_part.pop())
             else:
                 config_drive_part = '%s%s' % (device, new_part.pop())

ironic_lib/tests/test_disk_utils.py

@@ -1432,7 +1432,7 @@ class WholeDiskConfigDriveTestCases(base.IronicLibTestCase):
                         self.node_uuid)
             expected_part = '%s-part4' % self.dev
         elif is_nvme_device:
-            self.dev = '/dev/nvmefake'
+            self.dev = '/dev/nvmefake0'
             expected_part = '%sp4' % self.dev
         else:
             expected_part = '/dev/fake4'

releasenotes/notes/fix-metadisk-partitioning-32d3fca274290dd6.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixes an issue where the incorrect partition naming was used for metadisk (md)
+    devices. See `Story 2006154 <https://storyboard.openstack.org/#!/story/2006154>`_
+    for details.