Add version api ref

Change-Id: I93cb484a1f3ae533558ecde0cd79c8b6b2fb18f1

api-ref/source/index.rst

@@ -6,6 +6,7 @@ Watcher API
 
 .. rest_expand_all::
 
+.. include:: watcher-api-versions.inc
 .. include:: watcher-api-v1-audittemplates.inc
 .. include:: watcher-api-v1-audits.inc
 .. include:: watcher-api-v1-actionplans.inc
@@ -13,4 +14,4 @@ Watcher API
 .. include:: watcher-api-v1-goals.inc
 .. include:: watcher-api-v1-strategies.inc
 .. include:: watcher-api-v1-services.inc
-.. include:: watcher-api-v1-scoring_engines.inc
+.. include:: watcher-api-v1-scoring_engines.inc

api-ref/source/parameters.yaml

@@ -1,3 +1,42 @@
+# variables in header
+header_version:
+  description: |
+    Specific API microversion used to generate this response.
+  in: header
+  required: true
+  type: string
+openstack-api-max-version:
+  description: |
+    Maximum API microversion supported by this endpoint, eg. "1.1"
+  in: header
+  required: true
+  type: string
+openstack-api-min-version:
+  description: |
+    Minimum API microversion supported by this endpoint, eg. "1.0"
+  in: header
+  required: true
+  type: string
+openstack-api-version:
+  description: >
+    A request SHOULD include this header to indicate to the Watcher API service what
+    version the client supports. The server will transform the response object into
+    compliance with the requested version, if it is supported, or return a
+    406 Not Acceptable error.
+    If this header is not supplied, the server will response with server minimum
+    supported version.
+  in: header
+  required: true
+  type: string
+openstack-request-id:
+  description: >
+    An unique ID for tracking the request. The request ID associated with the request
+    appears in the log lines for that request. By default, the middleware configuration
+    ensures that the request ID appears in the log files.
+  in: header
+  required: false
+  type: string
+
 # Path
 action_ident:
   description: |
@@ -457,3 +496,29 @@ uuid:
   in: body
   required: true
   type: string
+
+# Version
+version:
+  description: |
+    Versioning of this API response, eg. "1.1".
+  in: body
+  required: true
+  type: string
+version_description:
+  description: |
+    Descriptive text about the Watcher service.
+  in: body
+  required: true
+  type: string
+version_id:
+  description: |
+    Major API version, eg, "v1"
+  in: body
+  required: true
+  type: string
+versions:
+  description: |
+    Array of information about currently supported versions.
+  in: body
+  required: true
+  type: array

api-ref/source/samples/api-root-response.json

@@ -0,0 +1,30 @@
+{
+  "default_version": {
+    "id": "v1",
+    "links": [
+      {
+        "href": "http://controller:9322/v1/",
+        "rel": "self"
+      }
+    ],
+    "min_version": "1.0",
+    "status": "CURRENT",
+    "max_version": "1.1"
+  },
+  "description": "Watcher is an OpenStack project which aims to improve physical resources usage through better VM placement.",
+  "name": "OpenStack Watcher API",
+  "versions": [
+    {
+      "id": "v1",
+      "links": [
+        {
+          "href": "http://controller:9322/v1/",
+          "rel": "self"
+        }
+      ],
+      "min_version": "1.0",
+      "status": "CURRENT",
+      "max_version": "1.1"
+    }
+  ]
+}

api-ref/source/samples/api-v1-root-response.json

@@ -0,0 +1,80 @@
+{
+  "scoring_engines": [
+    {
+      "href": "http://controller:9322/v1/scoring_engines/",
+      "rel": "self"
+    },
+    {
+      "href": "http://controller:9322/scoring_engines/",
+      "rel": "bookmark"
+    }
+  ],
+  "media_types": [
+    {
+      "base": "application/json",
+      "type": "application/vnd.openstack.watcher.v1+json"
+    }
+  ],
+  "links": [
+    {
+      "href": "http://controller:9322/v1/",
+      "rel": "self"
+    },
+    {
+      "href": "http://docs.openstack.org/developer/watcher/dev/api-spec-v1.html",
+      "type": "text/html",
+      "rel": "describedby"
+    }
+  ],
+  "actions": [
+    {
+      "href": "http://controller:9322/v1/actions/",
+      "rel": "self"
+    },
+    {
+      "href": "http://controller:9322/actions/",
+      "rel": "bookmark"
+    }
+  ],
+  "audit_templates": [
+    {
+      "href": "http://controller:9322/v1/audit_templates/",
+      "rel": "self"
+    },
+    {
+      "href": "http://controller:9322/audit_templates/",
+      "rel": "bookmark"
+    }
+  ],
+  "action_plans": [
+    {
+      "href": "http://controller:9322/v1/action_plans/",
+      "rel": "self"
+    },
+    {
+      "href": "http://controller:9322/action_plans/",
+      "rel": "bookmark"
+    }
+  ],
+  "services": [
+    {
+      "href": "http://controller:9322/v1/services/",
+      "rel": "self"
+    },
+    {
+      "href": "http://controller:9322/services/",
+      "rel": "bookmark"
+    }
+  ],
+  "audits": [
+    {
+      "href": "http://controller:9322/v1/audits/",
+      "rel": "self"
+    },
+    {
+      "href": "http://controller:9322/audits/",
+      "rel": "bookmark"
+    }
+  ],
+  "id": "v1"
+}

api-ref/source/watcher-api-versions.inc

@@ -0,0 +1,81 @@
+.. -*- rst -*-
+
+============
+API versions
+============
+
+In order to bring new features to users over time, the Watcher API
+supports versioning. There are two kinds of versions in Watcher.
+
+- ''major versions'', which have dedicated URLs.
+- ''microversions'', which can be requested using the
+  ``OpenStack-API-Version`` header.
+
+.. note:: The maximum microversion depends on release.
+  Please reference:
+  `API Microversion History
+  <https://docs.openstack.org/watcher/latest/contributor/api_microversion_history.html>`__
+  for API microversion history details.
+
+The Version API resource works differently from other API resources as they *do not*
+require authentication.
+
+If Watcher receives a request with unsupported version, it responds with a 406 Not Acceptable,
+along with the -Min- and -Max- headers that it can support.
+
+List API versions
+=================
+
+.. rest_method::  GET /
+
+This fetches all the information about all known major API versions in the
+deployment. Links to more specific information will be provided for each major
+API version, as well as information about supported min and max microversions.
+
+Normal response codes: 200
+
+Request
+-------
+
+Response Example
+----------------
+
+.. rest_parameters::  parameters.yaml
+
+    - description: version_description
+    - versions: versions
+    - version: version
+    - id: version_id
+    - links: links
+    - min_version: openstack-api-min-version
+    - max_version: openstack-api-max-version
+
+.. literalinclude:: samples/api-root-response.json
+   :language: javascript
+
+
+Show v1 API
+===========
+
+.. rest_method::  GET /v1/
+
+Show all the resources within the Watcher v1 API.
+
+Normal response codes: 200
+
+Request
+-------
+
+Response Example
+----------------
+
+.. rest_parameters::  parameters.yaml
+
+    - id: version_id
+    - links: links
+    - OpenStack-API-Version: header_version
+    - OpenStack-API-Minimum-Version: openstack-api-min-version
+    - OpenStack-API-Maximum-Version: openstack-api-max-version
+
+.. literalinclude:: samples/api-v1-root-response.json
+   :language: javascript