utils, examples: Add ExperimentManager CM

Adds an ExperimentManager context manager for scripts:

 - No more ugly stack traces after execution if something goes wrong

 - No more ugly and easy to forget try-finally blocks

1 files changed, 2 insertions, 4 deletions

diff --git a/examples/mouse.py b/examples/mouse.py
index 5ff5c6a..026b3bc 100755
--- a/examples/mouse.py
+++ b/examples/mouse.py
@@ -3,6 +3,7 @@
 # An example script using the rumba package
 
 from rumba.model import *
+from rumba.utils import ExperimentManager
 
 # import testbed plugins
 import rumba.testbeds.emulab as emulab
@@ -15,7 +16,6 @@ import rumba.prototypes.ouroboros as our
 import rumba.prototypes.rlite as rl
 import rumba.prototypes.irati as irati
 
-
 log.set_logging_level('DEBUG')
 
 
@@ -102,8 +102,6 @@ exp = rl.Experiment(tb, nodes = [a, b, c, d, e, f, g, h, i, j, k, l, m, n])
 
 print(exp)
 
-try:
+with ExperimentManager(exp):
     exp.swap_in()
     exp.bootstrap_prototype()
-finally:
-    exp.swap_out()