Patching multiple Debian 6 LXC containers

lxcpatch.py

#!/usr/bin/python

import os, sys
import subprocess

LXC_BASE = '/var/lib/lxc'

def patch_sources_list(path):
    lts_lines = ['# LTS repository',
        'deb http://http.debian.net/debian/ squeeze-lts main contrib non-free',
        'deb-src http://http.debian.net/debian/ squeeze-lts main contrib non-free']
    lines = file(path).readlines()
    
    for line in lines:
        if line.startswith('deb http://http.debian.net/debian/ squeeze-lts'):
            return
    else:
        lines += lts_lines
        outf = file(path, 'w')
        outf.write('\n'.join(lines))

def lxc_exec(lxc_root, command):
    command = 'chroot %s %s' % (lxc_root, command)    
    subprocess.call(command, shell=True)

# patch LXC

for lxc_name in os.listdir(LXC_BASE):
    lxc_root = os.path.join(LXC_BASE, lxc_name, 'rootfs')
    if not os.path.isdir(lxc_root):
        print >> sys.stderr, '%s is not a directory' % lxc_root
        continue

    apt_sources_list = os.path.join(lxc_root, 'etc/apt/sources.list')
    patch_sources_list(apt_sources_list)
    
    lxc_exec(lxc_root, 'apt-get update')
    lxc_exec(lxc_root, 'apt-get install libc6')