Fix Redfish handle no continuous override boot src

Some hardware Redfish services have dropped support for continuously
overriding the boot source when the boot mode is Unified Extensible
Firmware Interface (UEFI). See this discussion:
http://lists.openstack.org/pipermail/openstack-discuss/2020-April/014543.html

A workaround falls back to one-time override, restoring it on every
reboot or power on. [1] However, it does not work, because, per the
Distributed Management Task Force (DMTF) Redfish standard, one-time
override is disabled on the next boot cycle. [2] This fixes that by
explicitly setting the boot source override to one-time every time it is
restored.

[1] https://storyboard.openstack.org/#!/story/2007527
[2] https://redfish.dmtf.org/schemas/v1/ComputerSystem.v1_11_0.json

Story: 2007733
Task: 39897
Change-Id: I6f5a11a77e7b16cdd0d837fdec51c3e9aeea9a31

ironic/drivers/modules/redfish/management.py

@@ -69,19 +69,28 @@ if sushy:
         v: k for k, v in INDICATOR_MAP.items()}
 
 
-def _set_boot_device(task, system, device, enabled=None):
+def _set_boot_device(task, system, device, persistent=False):
     """An internal routine to set the boot device.
 
     :param task: a task from TaskManager.
     :param system: a Redfish System object.
     :param device: the Redfish boot device.
-    :param enabled: Redfish boot device persistence value or None.
+    :param persistent: Boolean value. True if the boot device will
+                       persist to all future boots, False if not.
+                       Default: False.
     :raises: SushyError on an error from the Sushy library
     """
+    desired_enabled = BOOT_DEVICE_PERSISTENT_MAP_REV[persistent]
+    current_enabled = system.boot.get('enabled')
+
+    # NOTE(etingof): this can be racy, esp if BMC is not RESTful
+    enabled = (desired_enabled
+               if desired_enabled != current_enabled else None)
+
     try:
         system.set_system_boot_options(device, enabled=enabled)
     except sushy.exceptions.SushyError as e:
-        if enabled == sushy.BOOT_SOURCE_ENABLED_CONTINUOUS:
+        if desired_enabled == sushy.BOOT_SOURCE_ENABLED_CONTINUOUS:
             # NOTE(dtantsur): continuous boot device settings have been
             # removed from Redfish, and some vendors stopped supporting
             # it before an alternative was provided. As a work around,
@@ -194,15 +203,10 @@ class RedfishManagement(base.ManagementInterface):
 
         system = redfish_utils.get_system(task.node)
 
-        desired_persistence = BOOT_DEVICE_PERSISTENT_MAP_REV[persistent]
-        current_persistence = system.boot.get('enabled')
-
-        # NOTE(etingof): this can be racy, esp if BMC is not RESTful
-        enabled = (desired_persistence
-                   if desired_persistence != current_persistence else None)
         try:
-            _set_boot_device(task, system, BOOT_DEVICE_MAP_REV[device],
-                             enabled=enabled)
+            _set_boot_device(
+                task, system, BOOT_DEVICE_MAP_REV[device],
+                persistent=persistent)
         except sushy.exceptions.SushyError as e:
             error_msg = (_('Redfish set boot device failed for node '
                            '%(node)s. Error: %(error)s') %

ironic/tests/unit/drivers/modules/redfish/test_management.py

@@ -215,7 +215,8 @@ class RedfishManagementTestCase(db_base.DbTestCase):
             task.driver.management.restore_boot_device(task, fake_system)
 
             fake_system.set_system_boot_options.assert_called_once_with(
-                sushy.BOOT_SOURCE_TARGET_HDD, enabled=None)
+                sushy.BOOT_SOURCE_TARGET_HDD,
+                enabled=sushy.BOOT_SOURCE_ENABLED_ONCE)
             # The stored boot device is kept intact
             self.assertEqual(
                 sushy.BOOT_SOURCE_TARGET_HDD,
@@ -244,7 +245,8 @@ class RedfishManagementTestCase(db_base.DbTestCase):
             task.driver.management.restore_boot_device(task, fake_system)
 
             fake_system.set_system_boot_options.assert_called_once_with(
-                sushy.BOOT_SOURCE_TARGET_HDD, enabled=None)
+                sushy.BOOT_SOURCE_TARGET_HDD,
+                enabled=sushy.BOOT_SOURCE_ENABLED_ONCE)
             self.assertTrue(mock_log.called)
             # The stored boot device is kept intact
             self.assertEqual(

releasenotes/notes/fix-redfish-sadness-workaround-ed02cb310ff369f4.yaml

@@ -0,0 +1,11 @@
+---
+fixes:
+  - |
+    Fixes a workaround for hardware that does not support persistent
+    boot device setting with the ``redfish`` or ``idrac-redfish``
+    management interface implementation. When such situation is
+    detected, ironic falls back to one-time boot device setting,
+    restoring it on every reboot or power on.
+
+    For more information, see `story 2007733
+    <https://storyboard.openstack.org/#!/story/2007733>`_.