Extend root device hints to support "rotational"

This patch is extending the root device hints to also consider if a disk
is a rotational device or not. This hint makes it easier to separate
SSDs and HDDs when selecting the device to deploy the image onto.

Partial-Bug: #1599517
Change-Id: I270fe57df825929bdef7911b3a6757cf7163a5f1

ironic_python_agent/hardware.py

@@ -19,10 +19,12 @@ import os
 import shlex
 import time
 
+
 import netifaces
 from oslo_concurrency import processutils
 from oslo_config import cfg
 from oslo_log import log
+from oslo_utils import strutils
 from oslo_utils import units
 import pint
 import psutil
@@ -604,6 +606,10 @@ class GenericHardwareManager(HardwareManager):
 
             def match(hint, current_value, device):
                 hint_value = root_device_hints[hint]
+
+                if hint == 'rotational':
+                    hint_value = strutils.bool_from_string(hint_value)
+
                 if hint_value != current_value:
                     LOG.debug("Root device hint %(hint)s=%(value)s does not "
                               "match the device %(device)s value of "
@@ -617,14 +623,17 @@ class GenericHardwareManager(HardwareManager):
             def check_device_attrs(device):
                 for key in ('model', 'wwn', 'serial', 'vendor',
                             'wwn_with_extension', 'wwn_vendor_extension',
-                            'name'):
+                            'name', 'rotational'):
                     if key not in root_device_hints:
                         continue
 
                     value = getattr(device, key)
-                    if not value:
+                    if value is None:
                         return False
-                    value = utils.normalize(value)
+
+                    if isinstance(value, six.string_types):
+                        value = utils.normalize(value)
+
                     if not match(key, value, device.name):
                         return False
 

ironic_python_agent/tests/unit/test_hardware.py

@@ -448,7 +448,7 @@ class TestGenericHardwareManager(test_base.BaseTestCase):
             hardware.BlockDevice(name='/dev/sdb',
                                  model=model,
                                  size=10737418240,
-                                 rotational=False,
+                                 rotational=True,
                                  vendor='fake-vendor',
                                  wwn='fake-wwn',
                                  wwn_with_extension='fake-wwnven0',
@@ -485,6 +485,11 @@ class TestGenericHardwareManager(test_base.BaseTestCase):
         self._get_os_install_device_root_device_hints(
             {'name': '/dev/sdb'}, '/dev/sdb')
 
+    def test_get_os_install_device_root_device_hints_rotational(self):
+        for value in (True, 'true', 'on', 'y', 'yes'):
+            self._get_os_install_device_root_device_hints(
+                {'rotational': value}, '/dev/sdb')
+
     @mock.patch.object(hardware, 'list_all_block_devices')
     @mock.patch.object(hardware, 'get_cached_node')
     def test_get_os_install_device_root_device_hints_no_device_found(

releasenotes/notes/root-device-hints-rotational-67e6e61074c26561.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - Extend the root device hints to identify whether a disk is rotational
+    or not.