Ability to execute a MPI jail on other computer than the group root

yggdrasil/task_lib/mpi_executor.py

@@ -7,8 +7,10 @@ class MPIExecutor(Executor):
 
     def __init__(self, name, command, jail, end=False, timeout=-1,
                                                     encoding=consts.encoding,
-                                                    long_opt=False) :
+                                                    long_opt=False,
+                                                    exec_rank="0") :
         Executor.__init__(self, jail, end, name, timeout, encoding)
+        self.exec_rank = exec_rank;
         if long_opt :
             self.command = "{} --NETWORK={} --PORT={}".format(command,
                                                     self.group.ID,
@@ -18,7 +20,7 @@ class MPIExecutor(Executor):
                                                    self.group.server_number)
 
     def run(self) :
-        self.framework.exec_on("0",
+        self.framework.exec_on(self.exec_rank,
                 self.command,
                 consts.TRUE,
                 "0",