PAIN POINT

ATM we can'tscw exec on some machine with no public IP attached.

DIAGNOSTIC

exec CMD looks to rely ona call to utils.SSHExec.
So... we could use some ssh tunneling to keep it working under this kind of circumstances.

PROPOSALS

1. Scaleway brings a very secured SSH Gateway for all of its customers. scw uses this ssh gateway for all machines without public IP. Cons: it's not easy to provide & maintain a very secured service of that kind.
2. Customers can use one of their machines with public IP to access to their backend machine. This is probably the best solution.

Whatever the solution,exec can have an option-g, --gateway=SERVER. Also, a generalexec_gateway config parameter could be set to avoid passing this parameter at each exec call.