Added recover_cloud context

We need to recover cloud after the disaster scenarios, we should
remember actions, which were performed on the cloud nodes and we have to
reset all disaster changes which were made.

rally-contexts/recover_cloud_context.py

@@ -0,0 +1,45 @@
+from rally.benchmark.context import base
+from rally.common import log as logging
+from rally import consts
+from rally import osclients
+
+LOG = logging.getLogger(__name__)
+
+
+@base.context(name="recover_cloud", order=999)
+class CloudNodesContext(base.Context):
+    """This context allows to recover cloud after disaster tests"""
+
+    CONFIG_SCHEMA = {
+        "type": "object",
+        "$schema": consts.JSON_SCHEMA,
+        "additionalProperties": False,
+        "properties": {}
+    }
+	
+	ACTIONS = {
+	    "stop rabbitmq service": {
+		    "do": "/etc/init.d/rabbitmq-server stop",
+			"undo": "/etc/init.d/rabbitmq-server start"
+		},
+		"ban rabbitmq service with pcs": {
+		    "do": "pcs resource ban rabbitmq",
+			"undo": "pcs resource clear rabbitmq"
+		}
+	}
+
+    def setup(self):
+        """This method is called before the task start"""
+        self.context["actions"] = self.ACTIONS
+
+		# done_actions contains information about name of shaiker_id
+		# and action name which were executed, example:
+		# self.context["done_actions"] = [{"name": "node-1", "command": "ls"}]
+		self.context["done_actions"] = []
+
+    def cleanup(self):
+        """This method is called after the task finish"""
+        for action in self.context["done_actions"]:
+		    ## we need to import shaiker somehow :)
+            shaiker.run_command_on_node(action["node"],
+			                            ACTIONS[action["command"]]["undo"])