Hi William, I've been thinking about the null provider. There are two things that currently bother me about it.
Firstly the storage solution. I'm thinking we could just use some form of auth-key to prevent anyone but the provider writing to it, perhaps that would be sufficient. Secondly is the add machine problem. The point of the null provider is that it will never start an instance. The problem at this stage is that there is no way for the CLI (or API) at this stage to know whether or not it is possible to create a machine, so one will be added to state before the provider has got a chance to say yay or nay, as this comes during the provisioner task. What would likely happen then is that a machine would get added to state, and the provisioner would record an error against it as the provider says "nah, not creating a machine for you". Ideally we'd like to fail earlier, preferably at the "try to put this machine in state" phase. Perhaps we should have a sanity-check type callback into the provider with the constraints at the time we want to add a machine. This would give the null provider the early fail mechanism, and could also allow other providers to error if people as asking for constraints that really don't make sense. What do you think? Tim -- Juju-dev mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/juju-dev
