OpenNebula¶

The OpenNebula (ON) datasource supports the contextualisation disk.

OpenNebula’s virtual machines are contextualised (parametrised) by CD-ROM image, which contains a shell script context.sh, with custom variables defined on virtual machine start. There are no fixed contextualisation variables, but the datasource accepts many used and recommended across the documentation.

Datasource configuration¶

Datasource accepts the following configuration options:

dsmode:
  values: local, net, disabled
  default: net

These specify whether the datasource will be processed in local (pre-networking) stage, net (post-networking) stage or be disabled.

parseuser:
  default: nobody

Unprivileged system user used for contextualisation script processing.

Contextualisation disk¶

The following criteria are required:

Must be formatted with iso9660 filesystem or have a filesystem label of CONTEXT or CDROM.
Must contain the file context.sh with contextualisation variables. The file is generated by OpenNebula and has a KEY='VALUE' format that can be easily read by bash.

Contextualisation variables¶

There are no fixed or standard contextualisation variables in OpenNebula. The following variables were found in various places and in revisions of the OpenNebula documentation. Where multiple similar variables are specified, only the one found first is taken.

DSMODE: Datasource mode configuration override. Values are: local, net, disabled.

DNS
ETH<x>_IP
ETH<x>_NETWORK
ETH<x>_MASK
ETH<x>_GATEWAY
ETH<x>_GATEWAY6
ETH<x>_DOMAIN
ETH<x>_DNS
ETH<x>_SEARCH_DOMAIN
ETH<x>_MTU
ETH<x>_IP6
ETH<x>_IP6_ULA
ETH<x>_IP6_PREFIX_LENGTH
ETH<x>_IP6_GATEWAY

Static network configuration.

SET_HOSTNAME
HOSTNAME

Instance hostname.

PUBLIC_IP
IP_PUBLIC
ETH0_IP

If no hostname has been specified, cloud-init will try to create a hostname from the instance’s IP address in local dsmode. In net dsmode, cloud-init tries to resolve one of its IP addresses to get the hostname.

SSH_KEY
SSH_PUBLIC_KEY

One or multiple SSH keys (separated by newlines) can be specified.

USER_DATA
USERDATA

Cloud-init user data.

Example configuration¶

This example cloud-init configuration (cloud.cfg) enables OpenNebula datasource only in net mode.

disable_ec2_metadata: True
datasource_list: ['OpenNebula']
datasource:
  OpenNebula:
    dsmode: net
    parseuser: nobody

Example VM’s context section¶

CONTEXT=[
  SSH_KEY="$USER[SSH_KEY]
$USER[SSH_KEY1]
$USER[SSH_KEY2]",
  PUBLIC_IP="$NIC[IP]",
  USER_DATA="#cloud-config
# see https://help.ubuntu.com/community/CloudInit

packages: []

mounts:
- [vdc,none,swap,sw,0,0]
runcmd:
- echo 'Instance has been configured by cloud-init.' | wall
" ]