# Pastebin o9rdkOkM
user_data:
        str_replace:
          template: |
            #!/bin/bash
            echo -e "$master_ip primary-master.bfs.openwave.com primary-master" >> /etc/hosts
          params:
            $key_name: { get_param: key_name }
            $master_ip: { get_attr: [ master_management_port, fixed_ips, 0, ip_address ] }