Spec to Implement IP Availability

Specification to lay out new commands to be added to OSC.
New feature has been implemented and released for Neutron
and python-neutronclient to display IP usages.

Commands will display the IP usage across all networks, or
detailed IP usage specifics for a given network

Partially Implements Blueprint: neutron-ip-capacity

Change-Id: I1c25de1bd924d92a96c20d60fa24d9e966b92dcd

doc/source/specs/ip-availability.rst

@@ -0,0 +1,61 @@
+===============
+ip availability
+===============
+
+Network v2
+
+ip availability list
+--------------------
+
+List IP availability for network
+
+This command retrieves information about IP availability.
+Useful for admins who need a quick way to check the
+IP availability for all associated networks.
+List specifically returns total IP capacity and the
+number of allocated IP addresses from that pool.
+
+.. program:: ip availability list
+.. code:: bash
+
+    os ip availability list
+        [--ip-version {4,6}]
+        [--project <project>]
+
+.. option:: --ip-version {4,6}
+
+    List IP availability for specific version
+    (Default is 4)
+
+.. option:: --project <project>
+
+    List IP availability for specific project
+    (name or ID)
+
+ip availability show
+--------------------
+
+Show network IP availability details
+
+This command retrieves information about IP availability.
+Useful for admins who need a quick way to
+check the IP availability and details for a
+specific network.
+
+This command will return information about
+IP availability for the network as a whole, and
+return availability information for each individual
+subnet within the network as well.
+
+
+.. program:: ip availability show
+.. code:: bash
+
+    os ip availability show
+        <network>
+
+.. _ip_availability_show-network
+.. describe:: <network>
+
+    Show network IP availability for specific
+    network (name or ID)