gistfile1.json

"builders": [
    {
      "boot_command": [
        "<esc>",
        "<wait>linux ks=http://{{ .HTTPIP }}:{{ .HTTPPort }}/anaconda-ks.cfg<enter>"
      ],
      "boot_wait": "5s",
      "disk_size": 40000,
      "guest_os_type": "RedHat_64",
      "headless": true,
      "http_directory": "./http_directory",
      "iso_checksum": "bb9af2aea1344597e11070abe6b1fcd3",
      "iso_checksum_type": "md5",
      "iso_url": "http://mirrors.usinternet.com/centos/6.4/isos/x86_64/CentOS-6.4-x86_64-netinstall.iso",
      "ssh_password": "vagrant",
      "ssh_username": "root",
      "ssh_wait_timeout": "20m",
      "type": "virtualbox-iso",
    }