Add node_resource_consolidation doc

Partially Implements: blueprint node-resource-consolidation
Depends-on: Ia979781b32202c1821aa1cb91d24253fe6d7bd2d
Depends-on: I104c864d532c2092f5dc6f0c8f756ebeae12f09e

Change-Id: I8fa33a6559c9821e730f8e0babd8438ef45d7338

doc/source/strategies/node_resource_consolidation.rst

@@ -0,0 +1,95 @@
+====================================
+Node Resource Consolidation Strategy
+====================================
+
+Synopsis
+--------
+
+**display name**: ``Node Resource Consolidation Strategy``
+
+**goal**: ``Server Consolidation``
+
+    .. watcher-term:: watcher.decision_engine.strategy.strategies.node_resource_consolidation.NodeResourceConsolidation
+
+Requirements
+------------
+
+None.
+
+Metrics
+*******
+
+None
+
+Cluster data model
+******************
+
+Default Watcher's Compute cluster data model:
+
+    .. watcher-term:: watcher.decision_engine.model.collector.nova.NovaClusterDataModelCollector
+
+Actions
+*******
+
+Default Watcher's actions:
+
+    .. list-table::
+       :widths: 30 30
+       :header-rows: 1
+
+       * - action
+         - description
+       * - ``migration``
+         - .. watcher-term:: watcher.applier.actions.migration.Migrate
+       * - ``change_nova_service_state``
+         - .. watcher-term:: watcher.applier.actions.change_nova_service_state.ChangeNovaServiceState
+
+Planner
+*******
+
+Default Watcher's planner:
+
+    .. watcher-term:: watcher.decision_engine.planner.weight.WeightPlanner
+
+Configuration
+-------------
+
+Strategy parameters are:
+
+==================== ====== =======================================
+parameter            type   default Value description
+==================== ====== =======================================
+``host_choice``      String The way to select the server migration
+                            destination node, The value auto means
+                            that Nova schedular selects the
+                            destination node, and specify means
+                            the strategy specifies the destination.
+==================== ====== =======================================
+
+Efficacy Indicator
+------------------
+
+None
+
+Algorithm
+---------
+
+For more information on the Node Resource Consolidation Strategy please refer
+to: https://specs.openstack.org/openstack/watcher-specs/specs/train/approved/node-resource-consolidation.html
+
+How to use it ?
+---------------
+
+.. code-block:: shell
+
+    $ openstack optimize audittemplate create \
+      at1 server_consolidation \
+      --strategy node_resource_consolidation
+
+    $ openstack optimize audit create \
+      -a at1 -p host_choice=auto
+
+External Links
+--------------
+
+None.