Merge "Support Custom Workloads"

diff --cc docker/storperf-master/storperf/storperf_master.py
index 7a94af8,1025789..4cd7071
--- 1/docker/storperf-master/storperf/storperf_master.py
--- 2/docker/storperf-master/storperf/storperf_master.py
+++ b/docker/storperf-master/storperf/storperf_master.py
@@@ -355,15 -373,20 +373,25 @@@ class StorPerfMaster(object)
          stack_id = None
          if (self.stack_id is not None):
              stack_id = self.stack_id
 -            self.heat_stack.clean()
 +            try:
 +                self.heat_stack.clean()
 +            except Exception as e:
 +                self.logger.error("Stack creation failed")
 +                raise Exception(e)
 +            self.stack_id = None
          return stack_id
  
+     def executor_event(self, executor):
+         if executor.terminated:
+             self._test_executor = None
+ 
      def execute_workloads(self, metadata={}):
+         if (self._test_executor is not None and
+                 (not self._test_executor.terminated and
+                  self._test_executor.job_id is not None)):
+             raise Exception("ERROR: Job {} is already running".format(
+                 self._test_executor.job_id))
+ 
          if (self.stack_id is None):
              raise ParameterError("ERROR: Stack does not exist")