Add forward slash for node path patch

Ironic cli allow to patch attributes w/o forward slash
at the beginning:
    ironic node-update <node_id> add 'driver_info/attr'='my_attr'
Inspector fails if driver info in rules provided in same manner,
this change add head forward slash to path if it's missing.

Closes-Bug: #1529809
Change-Id: I4423184e15d5779c59a903b50554db0550ba3d83

ironic_inspector/node_cache.py

@@ -264,6 +264,12 @@ class NodeInfo(object):
         :param patches: JSON patches to apply
         :raises: ironicclient exceptions
         """
+        # NOTE(aarefiev): support path w/o ahead forward slash
+        # as Ironic cli does
+        for patch in patches:
+            if patch.get('path') and not patch['path'].startswith('/'):
+                patch['path'] = '/' + patch['path']
+
         LOG.debug('Updating node with patches %s', patches, node_info=self)
         self._node = self.ironic.node.update(self.uuid, patches)
 

ironic_inspector/test/test_node_cache.py

@@ -11,6 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import copy
 import json
 import time
 import unittest
@@ -502,9 +503,33 @@ class TestUpdate(test_base.NodeTest):
     def test_patch(self):
         self.ironic.node.update.return_value = mock.sentinel.node
 
-        self.node_info.patch(['patch'])
+        self.node_info.patch([{'patch': 'patch'}])
 
-        self.ironic.node.update.assert_called_once_with(self.uuid, ['patch'])
+        self.ironic.node.update.assert_called_once_with(self.uuid,
+                                                        [{'patch': 'patch'}])
+        self.assertIs(mock.sentinel.node, self.node_info.node())
+
+    def test_patch_path_wo_leading_slash(self):
+        self.ironic.node.update.return_value = mock.sentinel.node
+
+        patch = [{'op': 'add', 'path': 'driver_info/test', 'value': 42}]
+        expected_patch = copy.deepcopy(patch)
+        expected_patch[0]['path'] = '/' + 'driver_info/test'
+
+        self.node_info.patch(patch)
+
+        self.ironic.node.update.assert_called_once_with(self.uuid,
+                                                        expected_patch)
+        self.assertIs(mock.sentinel.node, self.node_info.node())
+
+    def test_patch_path_with_leading_slash(self):
+        self.ironic.node.update.return_value = mock.sentinel.node
+
+        patch = [{'op': 'add', 'path': '/driver_info/test', 'value': 42}]
+
+        self.node_info.patch(patch)
+
+        self.ironic.node.update.assert_called_once_with(self.uuid, patch)
         self.assertIs(mock.sentinel.node, self.node_info.node())
 
     def test_update_properties(self):

releasenotes/notes/patch-head-backslash-24bcdd03ba254bf2.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - Introspection rules (e.g. set-attribute action) now accept 'path'
+    field without leading forward slash as Ironic cli does.