cloud-init with Chef provisionning + register

cloud-init-with-chef.yml

#cloud-config

users:
  - name: demo
    sudo: ['ALL=(ALL) NOPASSWD:ALL']
    groups: sudo
    shell: /bin/bash

chef:
  install_type: "omnibus"
  omnibus_url: "https://www.opscode.com/chef/install.sh"
  force_install: false
  server_url: "https://api.opscode.com/organizations/cloudinit"
  node_name: "cloudinit-lala"
  validation_name: "cloudinit-validator"
  validation_key: |
    -----BEGIN RSA PRIVATE KEY-----
    MIIEpQIBAAKCAQEAqAKSmwTJonSpYZfjkIHMCypK1adiawYyM9et/sFnp7csXwiu
    ...
    -----END RSA PRIVATE KEY-----
output: {all: '| tee -a /var/log/cloud-init-output.log'}
runcmd:
  - while [ ! -e /usr/bin/chef-client ]; do sleep 5; done; chef-client
disable_ec2_metadata: true

There is an omnibus version parameter as per https://gist.github.com/RichardBronosky/50caf2f91362a5ce3ff3b03e1513e8e0#file-user-data-txt-L104