tree mode: fix error with intermediate gateways (#471)

Intermediate gateways create a TreeWorker with a topology passed by the parent node and a new root node, and instantiate their own PropagationNodeRouter object. When such TreeWorker is scheduled, we should set the task's default router from it properly. The error seen was: ... File "ClusterShell/Propagation.py", line 411, in ev_close self.task.router.mark_unreachable(gateway) AttributeError: 'NoneType' object has no attribute 'mark_unreachable' Fixes #471

Author: thiell

lib/ClusterShell/Task.py

@@ -421,10 +421,25 @@ def load_topology(self, topology_file):
  """
  self.topology = TopologyParser(topology_file).tree(_getshorthostname())
 
- def _default_router(self):
- if self.router is None:
- self.router = PropagationTreeRouter(str(self.topology.root.nodeset),
- self.topology)
+ def _default_router(self, router=None):
+ """
+ Helper to instantiate or bind a default PropagationTreeRouter
+ for the task which can then be shared by multiple workers.
+ Called by a TreeWorker when it is scheduled with this task.
+ """
+ if router is None:
+ if self.router is None:
+ # Init router with the task's topology (e.g. root node)
+ self.router = \
+ PropagationTreeRouter(str(self.topology.root.nodeset),
+ self.topology)
+ else:
+ if self.router is not None:
+ # Update default router if a different one is used by a worker.
+ logger = logging.getLogger(__name__)
+ logger.debug("_default_router: overriding previous default " \
+ "router %s with %s", self.router, router)
+ self.router = router
  return self.router
 
  def default(self, default_key, def_val=None):

lib/ClusterShell/Worker/Tree.py

@@ -202,7 +202,7 @@ def _set_task(self, task):
  DistantWorker._set_task(self, task)
  # Now bound to task - initalize router
  self.topology = self.topology or task.topology
- self.router = self.router or task._default_router()
+ self.router = task._default_router(self.router)
  self._launch(self.nodes)
  self._check_ini()