def advance_lcs(self, resource_id, new_state):
"""
attempt to advance the lifecycle state of a resource
@resource_id the resource id
@new_state the new lifecycle state
"""
# check that the resource exists
resource = self.RR.read(resource_id)
resource_type = self._get_resource_type(resource)
# check that we've been handed the correct object
if not resource_type == self.iontype:
raise NotImplementedError("Attempted to change lifecycle of a %s in a %s module" %
(resource_type, self.iontype))
# get the workflow that we need
restype_workflow = lcs_workflows.get(resource_type, None)
if not restype_workflow:
restype_workflow = lcs_workflows['Resource']
# check that the transition is possible
possible_transitions = restype_workflow.get_predecessors(new_state)
if not resource.lcstate in possible_transitions:
actions = []
for st, tr in possible_transitions.iteritems():
actions.append("%s -> %s" % (str(st), str(tr)))
raise NotImplementedError(("Attempted to change lifecycle of a %s from %s to %s; " +
"supported transitions are {%s}->%s") %
(self.iontype,
resource.lcstate,
new_state,
", ".join(actions),
new_state))
# check that precondition function exists
if not new_state in self.lcs_precondition:
raise NotImplementedError(
"Lifecycle precondition method '%s' not defined for %s!"
% (new_state, self.iontype))
precondition_fn = self.lcs_precondition[new_state]
# check that the precondition is met
if not precondition_fn(resource_id):
raise BadRequest(("Couldn't transition %s to state %s; "
+ "failed precondition")
% (self.iontype, new_state))
# get the transition event that takes us where we want to go
transition_event = possible_transitions[resource.lcstate]
log.debug("Moving %s resource life cycle to %s with transition event %s"
% (self.iontype, new_state, transition_event))
ret = self.RR.execute_lifecycle_transition(resource_id=resource_id,
transition_event=transition_event)
log.debug("Result of lifecycle transition was %s" % str(ret))
return ret
def execute_lifecycle_transition(self, resource_id='', transition_event='', current_lcstate=''):
self.assert_condition(not current_lcstate or current_lcstate in LCS, "Unknown life-cycle state %s" % current_lcstate)
res_obj = self.read(resource_id)
if current_lcstate and res_obj.lcstate != current_lcstate:
raise Inconsistent("Resource id=%s lcstate is %s, expected was %s" % (
resource_id, res_obj.lcstate, current_lcstate))
restype = type(res_obj).__name__
restype_workflow = lcs_workflows.get(restype, None)
if not restype_workflow:
restype_workflow = lcs_workflows['Resource']
new_state = restype_workflow.get_successor(res_obj.lcstate, transition_event)
if not new_state:
raise Inconsistent("Resource id=%s, type=%s, lcstate=%s has no transition for event %s" % (
resource_id, restype, res_obj.lcstate, transition_event))
res_obj.lcstate = new_state
res_obj.ts_updated = get_ion_ts()
updres = self.resource_registry.update(res_obj)
return new_state
