Allow instance_info to override node interface

This change allows instance_info values to override node interface
definitions, so non-admins can make temporary changes to various
interfaces.

Story: #2008652
Task: #41918
Change-Id: I6c3dc74705bde02bd02882d14838f184f8d4a5e3

doc/source/admin/index.rst

@@ -30,6 +30,7 @@ the services.
    Node Multi-Tenancy <node-multitenancy>
    Fast-Track Deployment <fast-track>
    Booting a Ramdisk or an ISO <ramdisk-boot>
+   Node Interface Override <node-interface-override>
 
 Drivers, Hardware Types and Hardware Interfaces
 -----------------------------------------------

doc/source/admin/node-interface-override.rst

@@ -0,0 +1,22 @@
+=======================
+Node Interface Override
+=======================
+
+Non-admins with temporary access to a node, may wish to specify different
+node interfaces. However, allowing them to set these interface values is
+problematic, as there is no automated way to ensure that the original
+interface values are restored.
+
+This guide details a method for temporarily overriding a node interface
+value.
+
+Overriding a Node Interface
+===========================
+
+In order to temporarily override a node interface, simply set the
+appropriate value in `instance_info`. For example, if you'd like to
+override a node's storage interface, run the following::
+
+  baremetal node set --instance-info storage_interface=cinder node-1
+
+`instance_info` values persist until after a node is cleaned.

ironic/common/driver_factory.py

@@ -69,7 +69,9 @@ def _attach_interfaces_to_driver(bare_driver, node, hw_type):
              the requested implementation is not compatible with it.
     """
     for iface in _INTERFACE_LOADERS:
-        impl_name = getattr(node, '%s_interface' % iface)
+        iface_name = '%s_interface' % iface
+        impl_name = node.instance_info.get(iface_name,
+                                           getattr(node, iface_name))
         impl = get_interface(hw_type, iface, impl_name)
         setattr(bare_driver, iface, impl)
 
@@ -204,20 +206,29 @@ def check_and_update_node_interfaces(node, hw_type=None):
         # NOTE(dtantsur): objects raise NotImplementedError on accessing fields
         # that are known, but missing from an object. Thus, we cannot just use
         # getattr(node, field_name, None) here.
+        set_default = True
+        if 'instance_info' in node and field_name in node.instance_info:
+            impl_name = node.instance_info.get(field_name)
+            if impl_name is not None:
+                # Check that the provided value is correct for this type
+                get_interface(hw_type, iface, impl_name)
+                set_default = False
+
         if field_name in node:
             impl_name = getattr(node, field_name)
             if impl_name is not None:
                 # Check that the provided value is correct for this type
                 get_interface(hw_type, iface, impl_name)
-                # Not changing the result, proceeding with the next interface
-                continue
+                set_default = False
 
-        impl_name = default_interface(hw_type, iface,
-                                      driver_name=node.driver, node=node.uuid)
+        if set_default:
+            impl_name = default_interface(hw_type, iface,
+                                          driver_name=node.driver,
+                                          node=node.uuid)
 
-        # Set the calculated default and set result to True
-        setattr(node, field_name, impl_name)
-        result = True
+            # Set the calculated default and set result to True
+            setattr(node, field_name, impl_name)
+            result = True
 
     return result
 

ironic/tests/unit/common/test_driver_factory.py

@@ -214,6 +214,26 @@ class CheckAndUpdateNodeInterfacesTestCase(db_base.DbTestCase):
                           driver_factory.check_and_update_node_interfaces,
                           node)
 
+    def test_create_node_valid_network_interface_instance_info_override(self):
+        instance_info = {'network_interface': 'noop',
+                         'storage_interface': 'noop'}
+        node = obj_utils.get_test_node(self.context,
+                                       instance_info=instance_info)
+        self.assertTrue(driver_factory.check_and_update_node_interfaces(node))
+        self.assertIsNone(node.network_interface)
+        self.assertIsNone(node.storage_interface)
+        self.assertEqual('noop', node.instance_info.get('network_interface'))
+        self.assertEqual('noop', node.instance_info.get('storage_interface'))
+
+    def test_create_node_invalid_network_interface_instance_info_override(
+            self):
+        instance_info = {'network_interface': 'banana'}
+        node = obj_utils.get_test_node(self.context,
+                                       instance_info=instance_info)
+        self.assertRaises(exception.InterfaceNotFoundInEntrypoint,
+                          driver_factory.check_and_update_node_interfaces,
+                          node)
+
     def _get_valid_default_interface_name(self, iface):
         i_name = 'fake'
         # there is no 'fake' network interface
@@ -506,6 +526,17 @@ class HardwareTypeLoadTestCase(db_base.DbTestCase):
         self.assertRaises(exception.InterfaceNotFoundInEntrypoint,
                           task_manager.acquire, self.context, node.id)
 
+    def test_build_driver_for_task_instance_info_override(self):
+        self.config(enabled_network_interfaces=['noop', 'neutron'])
+        instance_info = {'network_interface': 'neutron'}
+        node = obj_utils.create_test_node(self.context, driver='fake-hardware',
+                                          instance_info=instance_info,
+                                          **self.node_kwargs)
+        with task_manager.acquire(self.context, node.id) as task:
+            self.assertEqual(
+                getattr(task.driver, 'network').__class__.__name__,
+                'NeutronNetwork')
+
     def test_no_storage_interface(self):
         node = obj_utils.get_test_node(self.context)
         self.assertTrue(driver_factory.check_and_update_node_interfaces(node))

releasenotes/notes/instance-info-interface-override-287c7fcff1081469.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Allows node _interface values to be overridden by values in instance_info.
+    This gives non-admins a temporary method of setting interface values.