Added sample base scenario for shaiker_controller

Also changed type of controllers in config for cloud_nodes_context

rally-contexts/cloud_nodes_context.py

@@ -16,7 +16,7 @@ class CloudNodesContext(base.Context):
         "additionalProperties": False,
         "properties": {
             "controllers": {
-                "type": "list",
+                "type": "array",
                 "default": []
             }
         }

rally-scenarios/shaiker_controller.py

@@ -1 +1,12 @@
-## initial version
+from rally.benchmark.scenarios import base
+
+
+class shaiker_controller(base.Scenario):
+    """Sample plugin for shaiker."""
+
+    @base.scenario()
+    def sample_print(self):
+        print "its work"
+        print "controllers: ", self.context["controllers"]
+        self.context["nodes"] = ["10", "11", "12"]
+        print "nodes: ", self.context["nodes"]