# Copyright (C) 2012 Canonical Ltd.

# Copyright (C) 2012, 2013 Hewlett-Packard Development Company, L.P.

# Copyright (C) 2012 Yahoo! Inc.

#

# Author: Scott Moser <scott.moser@canonical.com>

# Author: Juerg Haefliger <juerg.haefliger@hp.com>

# Author: Joshua Harlow <harlowja@yahoo-inc.com>

#

# This file is part of cloud-init. See LICENSE file for license information.

from cloudinit.distros.parsers.resolv_conf import ResolvConf

from cloudinit.distros.parsers.sys_conf import SysConf

from cloudinit import log as logging

from cloudinit import util

LOG = logging.getLogger(__name__)

# Helper function to update a RHEL/SUSE /etc/sysconfig/* file

def update_sysconfig_file(fn, adjustments, allow_empty=False):

    if not adjustments:

        return

    (exists, contents) = read_sysconfig_file(fn)

    updated_am = 0

    for (k, v) in adjustments.items():

        if v is None:

            continue

        v = str(v)

        if len(v) == 0 and not allow_empty:

            continue

        contents[k] = v

        updated_am += 1

    if updated_am:

        lines = [

            str(contents),

        ]

        if not exists:

            lines.insert(0, util.make_header())

        util.write_file(fn, "\n".join(lines) + "\n", 0o644)

# Helper function to read a RHEL/SUSE /etc/sysconfig/* file

def read_sysconfig_file(fn):

    exists = False

    try:

        contents = util.load_file(fn).splitlines()

        exists = True

    except IOError:

        contents = []

    return (exists, SysConf(contents))

# Helper function to update RHEL/SUSE /etc/resolv.conf

def update_resolve_conf_file(fn, dns_servers, search_servers):

    try:

        r_conf = ResolvConf(util.load_file(fn))

        r_conf.parse()

    except IOError:

        util.logexc(LOG, "Failed at parsing %s reverting to an empty "

                    "instance", fn)

        r_conf = ResolvConf('')

        r_conf.parse()

    if dns_servers:

        for s in dns_servers:

            try:

                r_conf.add_nameserver(s)

            except ValueError:

                util.logexc(LOG, "Failed at adding nameserver %s", s)

    if search_servers:

        for s in search_servers:

            try:

                r_conf.add_search_domain(s)

            except ValueError:

                util.logexc(LOG, "Failed at adding search domain %s", s)

    util.write_file(fn, str(r_conf), 0o644)

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