A litte explanation in English is in the script itself. If motivated, I'll update this README. However improovement of the script is more important... Sorry.
へたれな英語を晒すのも勇気がいりますが、まぁ一応、英語で大分かきました。
それはそうとして、これは何かと言いますと、libvert にはデーモン起動とか、 ゲスト起動とかしたときにスクリプトをフックする機能があるのですが、 標準入力から XML 流し込まれたりで大変だったので、簡単ではありますが Ruby スクリプトを書きました。
忘れたころにまたアップデートすると思います。ご質問はなんなりと下記連絡先へ。
There is a hook function in libvert. Official explanation is available in libvert site.
Motivation of which I use this function is to enable NDP proxy on briding interface
when guest boots.
I tried pre-up function in /etc/network/interfaces, however if there are many guests,
name of the interface may not be fixed.
Therefore I decided to use the hook in libvert. It is a little difficult to operate it because libvert pour long long XML into script which hook cathes. I have to find interface name from the XML.
This tiny script makes it a little easier. Condition to do some actions can be described as object composition of Ruby. Inputed XML is parsed by REXML, and find required dara by XPath. (Though condition description by Ruby object is a litte complex. I may make function which converts LTSV (Labeled Tab-separated Values).) Actions can be programmed as Ruby methods.
Anyhow this script can 'dispatch' hooks from libvert and do something. Have fan!
Place this script as $SYSCONFDIR/libvirt/hooks/{daemon,qemu,lxc,network} and set executable. Symbolic link is good practice.
This script is hooked by libvert with 4 arguments and configuration information as XML from stdin.
This script is executed by like this. e.g. preparing QEMU guest starting:
path/to/libvirt/hooks/qemu guest_name prepare begin -
1st argument is 'object', 2nd is 'operation', 3rd is 'sub-operation' and 4th is 'extra argument'. If there is none, '-' is set.
This script dispatch 'action' according to the arguments, and execute the action described as a Ruby method.
When executing action, XML from stdin is usable as REXML document.
Copyright © SATO Taisuke <paina@paina.jp> 2014
Licensed under The BSD 2-Clause License. See LICENSE file.
Questions, proposals, pull requests(!?) etc. are welcomed.