Add Node Servicing to api-ref

Adding service verb and service_steps attributes to API reference.

Change-Id: I7078f3b9e415c30ab45291bef8c52a66ff7eab8c

api-ref/source/baremetal-api-v1-node-management.inc

@@ -450,6 +450,10 @@ detailed documentation of the Ironic State Machine is available
    ``disable_ramdisk`` can be provided to avoid booting the ramdisk during
    manual cleaning.
 
+.. versionadded:: 1.87
+   A node can be serviced by setting the provision target state to ``service``
+   with a list of ``service_steps``.
+
 Normal response code: 202
 
 Error codes:
@@ -468,6 +472,7 @@ Request
     - configdrive: configdrive
     - clean_steps: clean_steps
     - deploy_steps: deploy_steps
+    - service_steps: service_steps
     - rescue_password: rescue_password
     - disable_ramdisk: disable_ramdisk
 

api-ref/source/parameters.yaml

@@ -2029,6 +2029,15 @@ secure_boot:
     Indicates whether node is currently booted with secure_boot turned on.
   in: body
   type: boolean
+service_steps:
+  description: |
+    An ordered list of service steps that will be performed on the node. A
+    cleaning step is a dictionary with required keys 'interface' and 'step', and
+    optional key 'args'. If specified, the value for 'args' is a keyword variable
+    argument dictionary that is passed to the cleaning step method.
+  in: body
+  required: false
+  type: array
 shard:
   description: |
     A string indicating the shard this node belongs to.