[chef] Setting Chef Server URL for chef-metal

[Douglas Garstang < >]

How do I set the chef server url passed to a new machine created by chef-metal?

I've tried this:
with_chef_server Chef::Config[:chef_server_url],
                 client_name: Chef::Config[:node_name],

which doesn't do anything to client.rb (ie leaves it at 127.0.0.1). I've also tried this:         

with_chef_server node['provisioner']['chef_server_url'], {
      :client_name => machine_name,
      :signing_key_filename => Chef::Config[:client_key]
    }

which just throws an error. Is chef-metal properly documented somewhere? I have no idea where most of these variables are coming from.

Douglas