def parse_lsb_release(lines):
    """
    Extract OS id from content of /etc/lsb-release files (in Debian derived OSs).
    """
    name = 'unknown'
    version = ''
    for l in lines:
        if l.startswith('DISTRIB_ID='):
            name = l.strip()[11:].lower()
        elif l.startswith('DISTRIB_RELEASE='):
            version = l.strip()[16:].replace('.', '')
    return name, version
