task/full_sequential_finally: run commands on unwind/cleanup

Signed-off-by: Sage Weil <sage@redhat.com>

diff --git a/teuthology/task/full_sequential_finally.py b/teuthology/task/full_sequential_finally.py
new file mode 100644 (file)
index 0000000..a24a344
--- /dev/null
+++ b/teuthology/task/full_sequential_finally.py
@@ -0,0 +1,54 @@
+"""
+Task sequencer finally
+"""
+import sys
+import logging
+import contextlib
+
+from teuthology import run_tasks
+
+log = logging.getLogger(__name__)
+
+
+@contextlib.contextmanager
+def task(ctx, config):
+    """
+    Sequentialize a group of tasks into one executable block, run on cleanup
+
+    example::
+
+      tasks:
+      - foo:
+      - full_sequential_finally:
+        - final1:
+        - final2:
+      - bar:
+      - baz:
+
+    The final1 and final2 tasks will run when full_sequentiall_finally is torn
+    down, after the nested bar and baz tasks have run to completion, and right
+    before the preceding foo task is torn down.  This is useful if there are
+    additional steps you want to interject in a job during the shutdown (instead
+    of startup) phase.
+
+    :param ctx: Context
+    :param config: Configuration
+    """
+    try:
+        yield
+    finally:
+        for entry in config:
+            if not isinstance(entry, dict):
+                entry = ctx.config.get(entry, {})
+            ((taskname, confg),) = entry.iteritems()
+            log.info('In full_sequential_finally, running task %s...' % taskname)
+            mgr = run_tasks.run_one_task(taskname, ctx=ctx, config=confg)
+            if hasattr(mgr, '__enter__'):
+                try:
+                    mgr.__enter__()
+                finally:
+                    try:
+                        exc_info = sys.exc_info()
+                        mgr.__exit__(*exc_info)
+                    finally:
+                        del exc_info