Score Nova Version List Capability

At the DefCore Flag.14 meeting on 09-09-2015, the Committee [1]
discussed the possibility of scoring the Nova version list API, partly
in response to requests from the developer community expressing that
they were surprised to find some providers didn't support it in spite
of the need for it with standard clients that understand
microversioning.[2]  At the time additional capabilities for Nova were
considered, no test was available for this API, but one was very
recently created [3].

This patch adds initial scoring for the aforementioned API.

[1] http://eavesdrop.openstack.org/meetings/defcore_flag_14/2015/defcore_flag_14.2015-09-09-15.03.log.html#l-13
[2] https://bugs.launchpad.net/python-novaclient/+bug/1491579
[3] https://review.openstack.org/#/c/219873/7

Change-Id: I66aef52171f745779c44ea7b9b8e10c37ab8ed2b

2016.next.json

@@ -57,7 +57,9 @@
         "networks-l3-router",
         "networks-l2-CRUD",
         "networks-l3-CRUD",
-        "networks-security-groups-CRUD"],
+        "networks-security-groups-CRUD",
+        "compute-list-api-versions"
+      ],
       "deprecated": [
         "compute-servers-change"
       ],
@@ -88,6 +90,28 @@
     }
   },
   "capabilities": {
+    "compute-list-api-versions": {
+      "achievements": [
+        "foundation",
+        "complete",
+        "proximity",
+        "discover",
+        "future",
+        "atomic",
+        "stable",
+        "deployed"
+      ],
+      "admin": false,
+      "status": "advisory",
+      "description": "List supported versions of the Compute API",
+      "project": "nova",
+      "required-since": "",
+      "tests": {
+        "tempest.api.compute.test_versions.TestVersions.test_list_api_versions": {
+          "idempotent_id": "id-6c0a0990-43b6-4529-9b61-5fd8daf7c55c"
+        }
+      }
+    },
     "compute-auth-create": {
       "achievements": [
         "foundation",

working_materials/scoring.txt

@@ -92,3 +92,47 @@ Notes:
       * networks-security-groups-router
       * networks-security-groups-show
       * networks-security-groups-update
+
+Compute
+-------
+compute-list-api-versions:             [1,0,0] [1,1,1] [1,1,0] [1,1,1] [1] [74]
+
+Notes:
+  * There has been some discussion that this capability is not widely
+    deployed [1].  However it appears that in most cases the API either:
+    * Is present and works, but only if a non-SSL endpoint is exposed.
+      SSL endpoints may have issues with redirects (which may actually
+      merely be configuration issues).
+    * Is accidentally blocked due to load balancer or API gateway
+      misconfiguration which is being remedied by affected providers.
+    Taking those situations into account, it is believed that it's actually
+    safe to call this "widely deployed".
+  * I'm having trouble finding evidence that tools actually support this
+    API (refer to [2] for information about what constitutes "tools").
+    Unlike most of the CRUD-like API's, this one lists information about
+    the API versions available instead of on end user actionable resources
+    (such as instances or security groups), and the need to do so is newish
+    with the advent of microversioning.  Hence, I think many tools may not
+    actually support this yet.  Please feel free to provide evidence to the
+    contrary; I'd love to be proven wrong.
+  * Similarly, I'm having trouble finding evidence that clients [3] like
+    jClouds or Fog support this API (yet?) as they tend to focus on actions.
+    Please feel free to provide evidence to the contrary; I'd love to be
+    proven wrong.
+  * I'm tentatively scoring this API as Proximate [4].  Generally this applies
+    to CRUD operations (e.g. the delete API is considered proximate to the
+    create API).  However I'm providing a 1 here on the grounds that due
+    to the shift to microversioning in the Nova API, this will be somewhat
+    proximate to everything going forward.
+  * The DefCore Committee is considering this capability for inclusion
+    in it's projected 2016.01 Guideline even though the test for it wasn't
+    developed until (narrowly) outside the normal window for identifying
+    new Capabilities on account of strong indications from the community
+    that such a Capability is important for API microversioning going
+    forward [5].
+
+[1] https://bugs.launchpad.net/python-novaclient/+bug/1491579
+[2] http://git.openstack.org/cgit/openstack/defcore/tree/doc/source/process/CoreCriteria.rst#n44
+[3] http://git.openstack.org/cgit/openstack/defcore/tree/doc/source/process/CoreCriteria.rst#n48
+[4] http://git.openstack.org/cgit/openstack/defcore/tree/doc/source/process/CoreCriteria.rst#n90
+[5] http://eavesdrop.openstack.org/meetings/defcore_flag_14/2015/defcore_flag_14.2015-09-09-15.03.log.html#l-13