Add subnet onboard API ref

Closes-Bug: #2016413
Change-Id: Iefd9700ca999c7ab3ff1ea99252539692b66b4c3

api-ref/source/v2/index.rst

@@ -36,6 +36,7 @@ Layer 3 Networking
 .. include:: subnetpools.inc
 .. include:: subnetpool_prefix_ops.inc
 .. include:: subnets.inc
+.. include:: subnet_onboard_ops.inc
 .. include:: local-ips.inc
 ########
 Security

api-ref/source/v2/samples/subnets/subnets-onboard-request.json

@@ -0,0 +1 @@
+{"network_id": "30640c16-a281-4ec5-8ec0-da05a0a5578d"}

api-ref/source/v2/samples/subnets/subnets-onboard-response.json

@@ -0,0 +1,4 @@
+{
+  "subnetpool_id": "5b3d3ffd-109a-4bda-a03c-57b17989b215",
+  "cidr": "10.0.2.0/24"
+}

api-ref/source/v2/subnet_onboard_ops.inc

@@ -0,0 +1,46 @@
+.. -*- rst -*-
+
+==============================================
+Subnet onboard operations (subnet-onboard-ops)
+==============================================
+
+Onboard network subnets into a subnet pool
+
+Onboard subnets
+===============
+
+.. rest_method::  PUT /v2.0/subnetpools/{subnetpool_id}/onboard_network_subnets
+
+Onboard network subnets to a subnet pool.
+
+Normal response codes: 200
+
+Error response codes: 400
+
+Request
+-------
+
+.. rest_parameters:: parameters.yaml
+
+   - network_id: network_id
+   - subnetpool_id: subnetpool_id
+
+Request Example
+---------------
+
+.. literalinclude:: samples/subnets/subnets-onboard-request.json
+   :language: javascript
+
+Response Parameters
+-------------------
+
+.. rest_parameters:: parameters.yaml
+
+   - subnetpool_id: subnetpool_id
+   - cidr: cidr
+
+Response Example
+----------------
+
+.. literalinclude:: samples/subnets/subnets-onboard-response.json
+   :language: javascript