Guest Contextualization

The information defined at the VM Template building time is presented to the VM using the VMware VMCI channel. This information comes encoded in base64 can be gathered using the VMware Tools.


VMware tools are needed in the guestOS to enable several features (contextualization and networking feedback). Please install VMware Tools (for Windows) or Open Virtual Machine Tools (for *nix) in the guestOS.

In order to make your VMs aware of OpenNebula, you must install the official packages. Packages for both Linux and Windows exist that can collect this data and configure the supported parameters.

Parameter Description
SET_HOST Change the hostname of the VM. In Windows the machine needs to be restarted.
SSH_PUBLIC_KEY SSH public keys to add to authorized_keys file. This parameter only works with Linux guests.
USERNAME Create a new administrator user with the given user name. Only for Windows guests.
PASSWORD Password for the new administrator user. Used with USERNAME and only for Windows guests.
DNS Add DNS entries to resolv.conf file. Only for Linux guests.
NETWORK If set to “YES” vOneCloud will pass Networking for the different NICs onto the VM
START_SCRIPT Shell script to be executed at boot time by the VM to provision software within it
START_SCRIPT_BASE64 Same as START_SCRIPT but will be base64 decoded prior to be executed

In Linux guests, the information can be consumed using the following command (and acted accordingly):

$ vmtoolsd --cmd 'info-get guestinfo.opennebula.context' | base64 -d

Linux Packages

The following Linux distributions are supported supported:

  • CentOS/RedHat 6 and 7
  • Debian 7 and 8
  • Ubuntu from 12.04 to 15.05

The linux packages can be downloaded from its project page and installed in the guest OS. There is one rpm file for Debian and Ubuntu and an rpm for RHEL and CentOS. After installing the package shutdown the machine and create a new template.

Windows Package

The Windows versions are supported:

  • Windows 2008 R2
  • Windows 2012
  • Windows 2012 R2

The official addon-opennebula-context provides all the necessary files to run the contextualization in Windows 2008 R2.

The contextualization procedure is as follows:

  1. Download startup.vbs and context.ps1 to the Windows VM and save them in C:\.
  2. Open the Local Group Policy Dialog by running gpedit.msc. Under: Computer Configuration -> Windows Settings -> Scripts -> startup (right click); browse to the startup.vbs file and enable it as a startup script.

After that power off the VM and create a new template from it.