The problem here is that with instance groups, you *have* to create the great in advance. You have to create the group with the policy it's going to use before booting any instances into that group. We don't allow you to set policy on an existing group, because we have no way to apply that to existing instances.
The problem here is that with instance groups, you *have* to create the great in advance. You have to create the group with the policy it's going to use before booting any instances into that group. We don't allow you to set policy on an existing group, because we have no way to apply that to existing instances.