# Copyright (C) 2015 Canonical Ltd.

#

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

#

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

"""

Fan

---

**Summary:** configure ubuntu fan networking

This module installs, configures and starts the ubuntu fan network system. For

more information about Ubuntu Fan, see:

``https://wiki.ubuntu.com/FanNetworking``.

If cloud-init sees a ``fan`` entry in cloud-config it will:

    - write ``config_path`` with the contents of the ``config`` key

    - install the package ``ubuntu-fan`` if it is not installed

    - ensure the service is started (or restarted if was previously running)

**Internal name:** ``cc_fan``

**Module frequency:** per instance

**Supported distros:** ubuntu

**Config keys**::

    fan:

        config: |

            # fan 240

            10.0.0.0/8 eth0/16 dhcp

            10.0.0.0/8 eth1/16 dhcp off

            # fan 241

            241.0.0.0/8 eth0/16 dhcp

        config_path: /etc/network/fan

"""

from cloudinit import log as logging

from cloudinit.settings import PER_INSTANCE

from cloudinit import subp

from cloudinit import util

LOG = logging.getLogger(__name__)

frequency = PER_INSTANCE

BUILTIN_CFG = {

    'config': None,

    'config_path': '/etc/network/fan',

}

def stop_update_start(service, config_file, content, systemd=False):

    if systemd:

        cmds = {'stop': ['systemctl', 'stop', service],

                'start': ['systemctl', 'start', service],

                'enable': ['systemctl', 'enable', service]}

    else:

        cmds = {'stop': ['service', 'stop'],

                'start': ['service', 'start']}

    def run(cmd, msg):

        try:

            return subp.subp(cmd, capture=True)

        except subp.ProcessExecutionError as e:

            LOG.warning("failed: %s (%s): %s", service, cmd, e)

            return False

    stop_failed = not run(cmds['stop'], msg='stop %s' % service)

    if not content.endswith('\n'):

        content += '\n'

    util.write_file(config_file, content, omode="w")

    ret = run(cmds['start'], msg='start %s' % service)

    if ret and stop_failed:

        LOG.warning("success: %s started", service)

    if 'enable' in cmds:

        ret = run(cmds['enable'], msg='enable %s' % service)

    return ret

def handle(name, cfg, cloud, log, args):

    cfgin = cfg.get('fan')

    if not cfgin:

        cfgin = {}

    mycfg = util.mergemanydict([cfgin, BUILTIN_CFG])

    if not mycfg.get('config'):

        LOG.debug("%s: no 'fan' config entry. disabling", name)

        return

    util.write_file(mycfg.get('config_path'), mycfg.get('config'), omode="w")

    distro = cloud.distro

    if not subp.which('fanctl'):

        distro.install_packages(['ubuntu-fan'])

    stop_update_start(

        service='ubuntu-fan', config_file=mycfg.get('config_path'),

        content=mycfg.get('config'), systemd=distro.uses_systemd())

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