Handle conductor ctrl-c more appropriately

When a conductor program is interrupted via ctrl-c
or equivalent it is much nicer log that that has happened
and to reraise that exception.

This also slightly tweaks the 99 bottles song to make it
even better, by having more pieces/tasks, which makes it
possible to kill the program during each task and see how
the resumption works when a flow is composed of segments.

Change-Id: I5d242eba9a043ef96646ba74ea5928daa0691ed0

1 files changed, 4 insertions, 0 deletions

diff --git a/taskflow/conductors/backends/impl_blocking.py b/taskflow/conductors/backends/impl_blocking.py
index fb8a3c3..945f591 100644
--- a/taskflow/conductors/backends/impl_blocking.py
+++ b/taskflow/conductors/backends/impl_blocking.py
@@ -18,6 +18,7 @@ except ImportError:
     from contextlib2 import ExitStack  # noqa
 
 from debtcollector import removals
+from oslo_utils import excutils
 import six
 
 from taskflow.conductors import base
@@ -151,6 +152,9 @@ class BlockingConductor(base.Conductor):
                     consume = False
                     try:
                         f = self._dispatch_job(job)
+                    except KeyboardInterrupt:
+                        with excutils.save_and_reraise_exception():
+                            LOG.warn("Job dispatching interrupted: %s", job)
                     except Exception:
                         LOG.warn("Job dispatching failed: %s", job,
                                  exc_info=True)