Synnefo » snf-ganeti

The method of supporting guest operating systems in Ganeti is to have,

for each guest OS type, a directory containing a number of required

files. This directory must be present across all nodes (Ganeti doesn't

replicate it) in order for the OS to be usable by Ganeti.

There are six required files: *create*, *import*, *export*, *rename*,

*verify* (executables), *ganeti_api_version*, *variants.list* and

*parameters.list* (text files).

OSP_*name*

    Each OS parameter (see below) will be exported in its own

    variable, prefixed with ``OSP``, and upper-cased. For example, a

    ``dhcp`` parameter will be exported as ``OSP_DHCP``.

EXECUTABLE SCRIPTS

------------------

verify

~~~~~~

The *verify* script is used to verify consistency of the OS parameters

(see below). The command should take one or more arguments denoting

what checks should be performed, and return a proper exit code

depending on whether the validation failed or succeeded.

Currently (API version 20), only one parameter is supported:

``parameters``. This should validate the ``OSP_`` variables from the

environment, and output diagnostic message in case the validation

fails.

.. highlight:: sh

For the ``dhcp`` parameter given as example above, a verification

script could be::

    #!/bin/sh

    case $OSP_DHCP in

        ""|yes|no)

            ;;

        *)

            echo "Invalid value '$OSP_DHCP' for the dhcp parameter" 1>&2

            exit 1;

            ;;

    esac

    exit 0

TEXT FILES

----------

parameters.list

~~~~~~~~~~~~~~~

This file declares the parameters supported by the OS, one parameter

per line, with name and description (space and/or tab separated). For

example::

    dhcp Whether to enable (yes) or disable (no) dhcp

    root_size The size of the root partition, in GiB

The parameters can then be used in instance add or modification, as

follows::

    # gnt-instance add -O dhcp=no,root_size=8 …

Ganeti 2.3 and up is compatible with API version 10, 15 and 20. The OS

parameters and related scripts (verify) are only supported in

version 20. The variants functionality (variants.list, and OS_VARIANT

env. var) are supported/present only in version 15 and up.

Version 15 to 20

^^^^^^^^^^^^^^^^

The ``parameters.list`` file and ``verify`` script have been

added. For no parameters, an empty parameters file and an empty verify

script which returns success can be used.