.. This work is licensed under a Creative Commons Attribution 4.0 International License.
.. http://creativecommons.org/licenses/by/4.0
.. Copyright (c) 2017-2018 VMware, Inc.

MultiCloud Resources Capacity Check API
=======================================

To better expose VIM capabilities and available resources capacity to external
consumer, some extensions need to be done by MultiCloud.


Problem Description
===================

Current MultiCloud didn't expose any standard API/methods to check/publish the
resources capacity for each VIM, which makes external project can not realize
the capacity information of VIM. When a VIM with shortage resources was chosen
to deploy a bunch of VNFs, it will fail eventually. Exposing these information
will could let external project to make a better decision on choosing which VIM
to deploy the VNFs.


Propose Change
==============

Cloud Locations
---------------

Cloud latitude and longitude information is needed by OOF to determine the
distance between vGMuxInfra and vG. The latitude and longitude information
are part of A&AI complex schema[A&AI Complex Schema]_, which related to
cloud-region schema.

There is no change needed to MultiCloud, but cloud administrator need to
input these information when register a new VIM. Currently ESR Portal don't
expose these input forms to cloud administrator, need ESR team to add related
workflow to create complex data in A&AI and create a relationship between
location information and cloud-region record.

... [A&AI Complex Schema] https://gerrit.onap.org/r/gitweb?p=aai/aai-common.git;a=blob;f=aai-schema/src/main/resources/oxm/aai_oxm_v12.xml;h=e146c06ac675a1127ee11205c0ff2544e4d9a81d;hb=HEAD#l772


Available Resource Check
------------------------

A new API will be used by OOF to check the available cloud resources, which
will help OOF to make a better placement decision. OOF will give a resrouces
requirement of a specific deployment and a list of VIMs which need to be
check whether have enough resources for this deployment. The ouput of
Multicloud will be a list of VIMs which have enough resources.

There will be two part of APIs for this requirement, an check_vim_capacity API
will be added to MultiCloud borker to return a list of VIMs, another
API <vim_id>/capacity_check will be added to each MultiCloud plugins, and return
true or false based on whether the VIM have enought resources. When MultiCloud
broker receive a POST request on check_vim_capacity, it will request to each
<vim_id>/capacity_check API, and return a list of VIMs with a true in response
data.


Input of check_vim_capacity will be

::
  {
    "vCPU": int,  // number of cores
    "Memory": float,  // size of memory, GB
    "Storage": int, //GB
    "VIMs": array  // VIMs OOF wish to check with
  }

Output of check_vim_capacity will be

::
  {
    "VIMs": array  // VIMs satisfy with this resource requirement
  }

Input of <vim_id>/capacity_check will be

::
  {
    "vCPU": int,
    "Memory": float,
    "Storage": int,
  }


Output of <vim_id>/capacity_check will be

::
  {
    "result": bool
  }


Work Items
==========

#. Work with ESR team for location inport form.
#. Add check_vim_capacity API to MultiCloud Broker.
#. Add check_vim_capacity API to each MultiCloud Plugins.