Rebuild a node should trigger a client deletion on chef-server
When we ask to rebuild a node, it should be very usefull to delete client (not the node) on chef-server.
We assume that build process provide a validation.pem to create a new client.
When host is rebuilt a client is deleted on chef-server so new private
key can be generated using validation.pem
Selected chef environment is set for a client via provisioning template.
Optional Foreman can create client for host directly so no
validation.pem is used. A bootstrap method is set via new setting called