# Copyright (C) 2014 Rackspace, US Inc.
# Copyright (C) 2016 Matthew Thode.
#
# Author: Nate House <nathan.house@rackspace.com>
# Author: Matthew Thode <prometheanfire@gentoo.org>
#
# This file is part of cloud-init. See LICENSE file for license information.

from cloudinit import distros
from cloudinit import helpers
from cloudinit import log as logging
from cloudinit import subp
from cloudinit import util

from cloudinit.distros import net_util
from cloudinit.distros.parsers.hostname import HostnameConf

from cloudinit.settings import PER_INSTANCE

LOG = logging.getLogger(__name__)


class Distro(distros.Distro):
    locale_conf_fn = '/etc/locale.gen'
    network_conf_fn = '/etc/conf.d/net'
    resolve_conf_fn = '/etc/resolv.conf'
    hostname_conf_fn = '/etc/conf.d/hostname'
    init_cmd = ['rc-service']  # init scripts

    def __init__(self, name, cfg, paths):
        distros.Distro.__init__(self, name, cfg, paths)
        # This will be used to restrict certain
        # calls from repeatly happening (when they
        # should only happen say once per instance...)
        self._runner = helpers.Runners(paths)
        self.osfamily = 'gentoo'
        # Fix sshd restarts
        cfg['ssh_svcname'] = '/etc/init.d/sshd'

    def apply_locale(self, locale, out_fn=None):
        if not out_fn:
            out_fn = self.locale_conf_fn
        subp.subp(['locale-gen', '-G', locale], capture=False)
        # "" provides trailing newline during join
        lines = [
            util.make_header(),
            'LANG="%s"' % locale,
            "",
        ]
        util.write_file(out_fn, "\n".join(lines))

    def install_packages(self, pkglist):
        self.update_package_sources()
        self.package_command('', pkgs=pkglist)

    def _write_network(self, settings):
        entries = net_util.translate_network(settings)
        LOG.debug("Translated ubuntu style network settings %s into %s",
                  settings, entries)
        dev_names = entries.keys()
        nameservers = []

        for (dev, info) in entries.items():
            if 'dns-nameservers' in info:
                nameservers.extend(info['dns-nameservers'])
            if dev == 'lo':
                continue
            net_fn = self.network_conf_fn + '.' + dev
            dns_nameservers = info.get('dns-nameservers')
            if isinstance(dns_nameservers, (list, tuple)):
                dns_nameservers = str(tuple(dns_nameservers)).replace(',', '')
            # eth0, {'auto': True, 'ipv6': {}, 'bootproto': 'dhcp'}
            # lo, {'dns-nameservers': ['10.0.1.3'], 'ipv6': {}, 'auto': True}
            results = ''
            if info.get('bootproto') == 'dhcp':
                results += 'config_{name}="dhcp"'.format(name=dev)
            else:
                results += (
                    'config_{name}="{ip_address} netmask {netmask}"\n'
                    'mac_{name}="{hwaddr}"\n'
                ).format(name=dev, ip_address=info.get('address'),
                         netmask=info.get('netmask'),
                         hwaddr=info.get('hwaddress'))
                results += 'routes_{name}="default via {gateway}"\n'.format(
                    name=dev,
                    gateway=info.get('gateway')
                )
            if info.get('dns-nameservers'):
                results += 'dns_servers_{name}="{dnsservers}"\n'.format(
                    name=dev,
                    dnsservers=dns_nameservers)
            util.write_file(net_fn, results)
            self._create_network_symlink(dev)
            if info.get('auto'):
                cmd = ['rc-update', 'add', 'net.{name}'.format(name=dev),
                       'default']
                try:
                    (_out, err) = subp.subp(cmd)
                    if len(err):
                        LOG.warning("Running %s resulted in stderr output: %s",
                                    cmd, err)
                except subp.ProcessExecutionError:
                    util.logexc(LOG, "Running interface command %s failed",
                                cmd)

        if nameservers:
            util.write_file(self.resolve_conf_fn,
                            convert_resolv_conf(nameservers))

        return dev_names

    @staticmethod
    def _create_network_symlink(interface_name):
        file_path = '/etc/init.d/net.{name}'.format(name=interface_name)
        if not util.is_link(file_path):
            util.sym_link('/etc/init.d/net.lo', file_path)

    def _bring_up_interface(self, device_name):
        cmd = ['/etc/init.d/net.%s' % device_name, 'restart']
        LOG.debug("Attempting to run bring up interface %s using command %s",
                  device_name, cmd)
        try:
            (_out, err) = subp.subp(cmd)
            if len(err):
                LOG.warning("Running %s resulted in stderr output: %s",
                            cmd, err)
            return True
        except subp.ProcessExecutionError:
            util.logexc(LOG, "Running interface command %s failed", cmd)
            return False

    def _bring_up_interfaces(self, device_names):
        use_all = False
        for d in device_names:
            if d == 'all':
                use_all = True
        if use_all:
            # Grab device names from init scripts
            cmd = ['ls', '/etc/init.d/net.*']
            try:
                (_out, err) = subp.subp(cmd)
                if len(err):
                    LOG.warning("Running %s resulted in stderr output: %s",
                                cmd, err)
            except subp.ProcessExecutionError:
                util.logexc(LOG, "Running interface command %s failed", cmd)
                return False
            devices = [x.split('.')[2] for x in _out.split('  ')]
            return distros.Distro._bring_up_interfaces(self, devices)
        else:
            return distros.Distro._bring_up_interfaces(self, device_names)

    def _write_hostname(self, your_hostname, out_fn):
        conf = None
        try:
            # Try to update the previous one
            # so lets see if we can read it first.
            conf = self._read_hostname_conf(out_fn)
        except IOError:
            pass
        if not conf:
            conf = HostnameConf('')
        conf.set_hostname(your_hostname)
        gentoo_hostname_config = 'hostname="%s"' % conf
        gentoo_hostname_config = gentoo_hostname_config.replace('\n', '')
        util.write_file(out_fn, gentoo_hostname_config, 0o644)

    def _read_system_hostname(self):
        sys_hostname = self._read_hostname(self.hostname_conf_fn)
        return self.hostname_conf_fn, sys_hostname

    @staticmethod
    def _read_hostname_conf(filename):
        conf = HostnameConf(util.load_file(filename))
        conf.parse()
        return conf

    def _read_hostname(self, filename, default=None):
        hostname = None
        try:
            conf = self._read_hostname_conf(filename)
            hostname = conf.hostname
        except IOError:
            pass
        if not hostname:
            return default
        return hostname

    def set_timezone(self, tz):
        distros.set_etc_timezone(tz=tz, tz_file=self._find_tz_file(tz))

    def package_command(self, command, args=None, pkgs=None):
        if pkgs is None:
            pkgs = []

        cmd = list('emerge')
        # Redirect output
        cmd.append("--quiet")

        if args and isinstance(args, str):
            cmd.append(args)
        elif args and isinstance(args, list):
            cmd.extend(args)

        if command:
            cmd.append(command)

        pkglist = util.expand_package_list('%s-%s', pkgs)
        cmd.extend(pkglist)

        # Allow the output of this to flow outwards (ie not be captured)
        subp.subp(cmd, capture=False)

    def update_package_sources(self):
        self._runner.run("update-sources", self.package_command,
                         ["-u", "world"], freq=PER_INSTANCE)


def convert_resolv_conf(settings):
    """Returns a settings string formatted for resolv.conf."""
    result = ''
    if isinstance(settings, list):
        for ns in settings:
            result += 'nameserver %s\n' % ns
    return result

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