def _get_conf(self, conf_tree, key, arg_ok=False):
"""Get a list of cycles from a configuration setting.
key -- An option key in self.SECTION to locate the setting.
arg_ok -- A boolean to indicate whether an item in the list can have
extra arguments or not.
The value of the setting is expected to be split by shlex.split into a
list of items. If arg_ok is False, an item should be a string
representing a cycle or an cycle offset. If arg_ok is True, the cycle
or cycle offset string can, optionally, have an argument after a colon.
E.g.:
prune-remote-logs-at=-6h -12h
prune-datac-at=-6h:foo/* -12h:'bar/* baz/*' -1d
If arg_ok is False, return a list of cycles.
If arg_ok is True, return a list of (cycle, arg)
"""
items_str = conf_tree.node.get_value([self.SECTION, key])
if items_str is None:
return []
try:
items_str = env_var_process(items_str)
except UnboundEnvironmentVariableError as e:
raise ConfigValueError([self.SECTION, key], items_str, e)
items = []
ds = RoseDateShifter(task_cycle_time_mode=True)
for item_str in shlex.split(items_str):
if arg_ok and ":" in item_str:
item, arg = item_str.split(":", 1)
else:
item, arg = (item_str, None)
if ds.is_task_cycle_time_mode() and ds.is_offset(item):
cycle = ds.date_shift(offset=item)
else:
cycle = item
if arg_ok:
items.append((cycle, arg))
else:
items.append(cycle)
return items
