Attempting to shutdown an instance in "NOSTATE" gives misleading error message

[jichenjc]

I have a instance not in running state, it's in 'NOSTATE' for some reason, I am able to stop it in CLI but not able to stop in GUI, it tells me

'You are not allowed to shut off: xxxx'

this is misleading given info at
https://github.com/openstack/horizon/blob/master/horizon/tables/actions.py#L864

if policy don't allow me to do this ,we can tell it's
'You are not allowed to shut off: xxxx'

if it's because instance is not capable ,we should say something like
'xxxx not capable of action shut off' so it will be more helpful to debug and know the real cause

[jichenjc (jichenjc)]

it's because we didn't distinguish policy check and state check result from line 136 to 138

 130
 131 def _allowed(self, request, datum):
 132 policy_check = getattr(settings, "POLICY_CHECK_FUNCTION", None)
 133
 134 if policy_check and self.policy_rules:
 135 target = self.get_policy_target(request, datum)
 136 return (policy_check(self.policy_rules, request, target) and
 137 self.allowed(request, datum))
 138 return self.allowed(request, datum)
 139

[Vishal Manchanda (vishalmanchanda)]

will cover this in https://blueprints.launchpad.net/horizon/+spec/refactor-error-messages bp