无法将角色分配给Chef引导程序上的节点

I am bootstrapping a node using the Azure Chef Extension. I pass it a validation.pem (to create the node) and the client.rb to pass the org information to it. During this process, I would like to assign a role to that node but I can't seem to figure out how to do this. I can pass a runlist ([role:"my_role"]) but this only runs once and doesn't actually assign it at the server level. The only way I know how to do this is using the knife command. I don't really want to do this because when I bootstrap the machine using the Azure Extension, it's asynchronous - I don't know when it actually completes. I can't edit the node using the knife command until after it completes so this makes automating this process difficult. Can I create node and assign node to the role all in one shot? Can I pass the role assignment info inside the client.rb?I am bootstrapping a node using the Azure Chef