Deprecate the Direct Engine

Add deprecation warning at sahara startup and during each cluster
operation with direct engine. Also add documentation about direct engine
deprecation.

Implements blueprint: deprecate-direct-engine

Change-Id: Ic478918834d3627557b0ba43873e37d9e6ff7dc9

doc/source/userdoc/configuration.guide.rst

@@ -195,23 +195,25 @@ in the ``[oslo_messaging_qpid]`` section:
 Orchestration configuration
 ---------------------------
 
-By default sahara is configured to use the direct engine for instance
-creation. This engine makes calls directly to the services required
-for instance provisioning. Sahara can be configured to use the OpenStack
-Orchestration service for this task instead of the direct engine.
+By default sahara is configured to use the heat engine for instance
+creation. The heat engine uses the Openstack Orchestration service to
+provision instances. Sahara can be configured to use the direct engine for
+this purpose, but after the Liberty release it will be removed. This
+engine makes calls directly to the services required for instance
+provisioning. We recommend using the Openstack Orchestration service.
 
-To configure sahara to utilize the Orchestration service for instance
+To configure sahara to use the direct engine for instance
 provisioning the ``infrastructure_engine`` parameter should be modified in
 the configuration file as follows:
 
 .. sourcecode:: cfg
 
     [DEFAULT]
-    infrastructure_engine=heat
+    infrastructure_engine=direct
 
-There is feature parity between the direct and heat infrastructure
-engines. We recommend using the heat engine for provisioning as the
-direct is planned for deprecation.
+.. warning::
+    The direct engine will be removed after the Liberty release, we
+    recommend using the heat engine.
 
 .. _policy-configuration-label:
 

doc/source/userdoc/upgrade.guide.rst

@@ -119,3 +119,17 @@ should be placed in the same directory as the sahara configuration file or
 specified using the ``policy_file`` parameter. For more details about the
 policy file please see the
 :ref:`policy section in the configuration guide <policy-configuration-label>`.
+
+Kilo -> Liberty
+---------------
+
+Direct engine deprecation
++++++++++++++++++++++++++
+
+In the Liberty release the direct infrastructure engine has been deprecated
+and the heat infrastructure engine is now default. This means, that it is preferable
+to use heat engine instead now. In the Liberty release you can continue to
+operate clusters with the direct engine (create, delete, scale). Using heat engine only
+the delete operation is available on clusters that were created by the direct engine.
+After the Liberty release the direct engine will be removed, this means that you will
+only be able to delete clusters created with the direct engine.

sahara/main.py

@@ -31,6 +31,7 @@ from sahara.api import v11 as api_v11
 from sahara import config
 from sahara import context
 from sahara.i18n import _LI
+from sahara.i18n import _LW
 from sahara.openstack.common import systemd
 from sahara.plugins import base as plugins_base
 from sahara.service import api as service_api
@@ -50,7 +51,7 @@ opts = [
     cfg.StrOpt('os_region_name',
                help='Region name used to get services endpoints.'),
     cfg.StrOpt('infrastructure_engine',
-               default='direct',
+               default='heat',
                help='An engine which will be used to provision '
                     'infrastructure for Hadoop cluster.'),
     cfg.StrOpt('remote',
@@ -179,6 +180,11 @@ def _get_infrastructure_engine():
     LOG.debug("Infrastructure engine {engine} is loading".format(
         engine=CONF.infrastructure_engine))
 
+    if CONF.infrastructure_engine == "direct":
+        LOG.warning(_LW("Direct infrastructure engine is deprecated in Liberty"
+                        " release and will be removed after that release."
+                        " Use Heat infrastructure engine instead."))
+
     return _load_driver('sahara.infrastructure.engine',
                         CONF.infrastructure_engine)
 

sahara/service/direct_engine.py

@@ -40,11 +40,18 @@ LOG = logging.getLogger(__name__)
 SSH_PORT = 22
 
 
+def _warning_logger():
+    LOG.warning(_LW("Direct infrastructure engine is deprecated in Liberty"
+                    " release and will be removed after that release."
+                    " Use Heat infrastructure engine instead."))
+
+
 class DirectEngine(e.Engine):
     def get_type_and_version(self):
         return "direct.1.0"
 
     def create_cluster(self, cluster):
+        _warning_logger()
         ctx = context.ctx()
         self._update_rollback_strategy(cluster, shutdown=True)
 
@@ -75,6 +82,7 @@ class DirectEngine(e.Engine):
         self._update_rollback_strategy(cluster)
 
     def scale_cluster(self, cluster, node_group_id_map):
+        _warning_logger()
         ctx = context.ctx()
         cluster = g.change_cluster_status(cluster, "Scaling: Spawning")
 
@@ -110,6 +118,7 @@ class DirectEngine(e.Engine):
         return instance_ids
 
     def rollback_cluster(self, cluster, reason):
+        _warning_logger()
         rollback_info = cluster.rollback_info or {}
         self._update_rollback_strategy(cluster)