# -*- coding: utf-8 -*-
# vim: set et sts=2:
##############################################################################
#
# Copyright (c) 2010, 2011, 2012 Vifib SARL and Contributors.
# All Rights Reserved.
#
# WARNING: This program as such is intended to be used by professional
# programmers who take the whole responsibility of assessing all potential
# consequences resulting from its eventual inadequacies and bugs
# End users who are looking for a ready-to-use solution with commercial
# guarantees and support are strongly advised to contract a Free Software
# Service Company
#
# This program is Free Software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 3
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
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##############################################################################

from six.moves import configparser
import errno
import fcntl
import grp
import json
import logging
import math
import netaddr
import netifaces
import os
import glob
import pwd
import random
import shutil
import socket
import struct
import subprocess
import sys
import threading
import time
import traceback
import zipfile
import platform
from six.moves.urllib.request import urlopen
import six

import lxml.etree
import xml_marshaller.xml_marshaller

from slapos.util import dumps, mkdir_p, ipv6FromBin, binFromIpv6, lenNetmaskIpv6
import slapos.slap as slap
from slapos import version
from slapos import manager as slapmanager


logger = logging.getLogger("slapos.format")


def prettify_xml(xml):
  root = lxml.etree.fromstring(xml)
  return lxml.etree.tostring(root, pretty_print=True)


class OS(object):
  """Wrap parts of the 'os' module to provide logging of performed actions."""

  _os = os

  def __init__(self, conf):
    self._dry_run = conf.dry_run
    self._logger = conf.logger
    add = self._addWrapper
    add('chown')
    add('chmod')
    add('makedirs')
    add('mkdir')

  def _addWrapper(self, name):
    def wrapper(*args, **kw):
      arg_list = [repr(x) for x in args] + [
          '%s=%r' % (x, y) for x, y in six.iteritems(kw)
      ]
      self._logger.debug('%s(%s)' % (name, ', '.join(arg_list)))
      if not self._dry_run:
        getattr(self._os, name)(*args, **kw)
    setattr(self, name, wrapper)

  def __getattr__(self, name):
    return getattr(self._os, name)


class UsageError(Exception):
  pass


class NoAddressOnInterface(Exception):
  """
  Exception raised if there is no address on the interface to construct IPv6
  address with.

  Attributes:
    brige: String, the name of the interface.
  """

  def __init__(self, interface):
    super(NoAddressOnInterface, self).__init__(
      'No IPv6 found on interface %s to construct IPv6 with.' % interface
    )


class AddressGenerationError(Exception):
  """
  Exception raised if the generation of an IPv6 based on the prefix obtained
  from the interface failed.

  Attributes:
    addr: String, the invalid address the exception is raised for.
  """
  def __init__(self, addr):
    super(AddressGenerationError, self).__init__(
      'Generated IPv6 %s seems not to be a valid IP.' % addr
    )


def getPublicIPv4Address():
  test_list = [
    { "url": 'https://api.ipify.org/?format=json' , "json_key": "ip"},
    { "url": 'http://httpbin.org/ip', "json_key": "origin"},
    { "url": 'http://jsonip.com', "json_key": "ip"}]
  previous = None
  ipv4 = None
  for test in test_list:
    if ipv4 is not None:
      previous = ipv4
    try:
      ipv4 = json.load(urlopen(test["url"], timeout=15))[test["json_key"]]
    except:
      ipv4 = None
    if ipv4 is not None and ipv4 == previous:
      return ipv4

def callAndRead(argument_list, raise_on_error=True):
  popen = subprocess.Popen(argument_list,
                           stdout=subprocess.PIPE,
                           stderr=subprocess.STDOUT)
  result = popen.communicate()[0]
  if raise_on_error and popen.returncode != 0:
    raise ValueError('Issue while invoking %r, result was:\n%s' % (
                     argument_list, result))
  return popen.returncode, result


def isGlobalScopeAddress(a):
  """Returns True if a is global scope IP v4/6 address"""
  ip = netaddr.IPAddress(a)
  return not ip.is_link_local() and not ip.is_loopback() and \
      not ip.is_reserved() and ip.is_unicast()


def netmaskToPrefixIPv4(netmask):
  """Convert string represented netmask to its integer prefix"""
  return netaddr.strategy.ipv4.netmask_to_prefix[
          netaddr.strategy.ipv4.str_to_int(netmask)]

def getIfaceAddressIPv4(iface):
  """return dict containing ipv4 address netmask, network and broadcast address
  of interface"""
  if not iface in netifaces.interfaces():
    raise ValueError('Could not find interface called %s to use as gateway ' \
                      'for tap network' % iface)
  try:
    addresses_list = netifaces.ifaddresses(iface)[socket.AF_INET]
    if len (addresses_list) > 0:

      addresses = addresses_list[0].copy()
      addresses['network'] = str(netaddr.IPNetwork('%s/%s' % (addresses['addr'],
                                          addresses['netmask'])).cidr.network)
      return addresses
    else:
      return {}
  except KeyError:
    raise KeyError('Could not find IPv4 adress on interface %s.' % iface)

def getIPv4SubnetAddressRange(ip_address, mask, size):
  """Check if a given ipaddress can be used to create 'size'
  host ip address, then return list of ip address in the subnet"""
  ip = netaddr.IPNetwork('%s/%s' % (ip_address, mask))
  # Delete network and default ip_address from the list
  ip_list = [x for x in sorted(list(ip))
              if str(x) != ip_address and x.value != ip.cidr.network.value]
  if len(ip_list) < size:
    raise ValueError('Could not create %s tap interfaces from address %s.' % (
              size, ip_address))
  return ip_list

def _getDict(obj):
  """
  Serialize an object into dictionaries. List and dict will remains
  the same, basic type too. But encapsulated object will be returned as dict.
  Set, collections and other aren't handle for now.

  Args:
    obj: an object of any type.

  Returns:
    A dictionary if the given object wasn't a list, a list otherwise.
  """
  if isinstance(obj, list):
    return [_getDict(item) for item in obj]

  if isinstance(obj, dict):
    dikt = obj
  else:
    try:
      dikt = obj.__dict__
    except AttributeError:
      return obj

  return {
    key: _getDict(value)
    for key, value in six.iteritems(dikt)
    # do not attempt to serialize logger: it is both useless and recursive.
    # do not serialize attributes starting with "_", let the classes have some privacy
    if not key.startswith("_")
  }


class ComputeNode(object):
  """Object representing the compute_node"""

  def __init__(self, reference, interface=None, addr=None, netmask=None,
               ipv6_interface=None, software_user='slapsoft',
               tap_gateway_interface=None, tap_ipv6=None,
               instance_root=None, software_root=None, instance_storage_home=None,
               partition_list=None, config=None):
    """
    Attributes:
      reference: str, the reference of the compute_node.
      interface: str, the name of the compute_node's used interface.

      :param config: dict-like, holds raw data from configuration file
    """
    self.reference = str(reference)
    self.interface = interface
    self.partition_list = partition_list or []
    self.address = addr
    self.netmask = netmask
    self.ipv6_interface = ipv6_interface
    self.software_user = software_user
    self.tap_gateway_interface = tap_gateway_interface
    self.tap_ipv6 = tap_ipv6

    # Used to be static attributes of the class object - didn't make sense (Marco again)
    assert instance_root is not None and software_root is not None, \
           "ComputeNode's instance_root and software_root must not be empty!"
    self.software_root = software_root
    self.instance_root = instance_root
    self.instance_storage_home = instance_storage_home

    # The following properties are updated on update() method
    self.public_ipv4_address = None
    self.os_type = None
    self.python_version = None
    self.slapos_version = None

    # attributes starting with '_' are saved from serialization
    # monkey-patch use of class instead of dictionary
    if config is None:
      logger.warning("Compute Node needs config in constructor to allow managers.")

    self._config = config if config is None or isinstance(config, dict) else config.__dict__
    self._manager_list = slapmanager.from_config(self._config)

  def __getinitargs__(self):
    return (self.reference, self.interface)

  def getAddress(self):
    """
    Return a list of the interface address not attributed to any partition (which
    are therefore free for the compute_node itself).

    Returns:
      False if the interface isn't available, else the list of the free addresses.
    """
    if self.interface is None:
      return {'addr': self.address, 'netmask': self.netmask}

    compute_partition_address_list = []
    for partition in self.partition_list:
      for address in partition.address_list:
        if netaddr.valid_ipv6(address['addr']):
          compute_partition_address_list.append(address['addr'])
    # Going through addresses of the compute_node's interface
    available_address_list = self.interface.getGlobalScopeAddressList()
    # First scan: prefer the existing address, as the available_address_list
    #             might be sorted differently
    for address_dict in available_address_list:
      if self.address == address_dict['addr']:
        if self.address not in compute_partition_address_list:
          return address_dict

    # Second scan: take first not occupied address
    for address_dict in available_address_list:
      # Comparing with compute_node's partition addresses
      if address_dict['addr'] not in compute_partition_address_list:
        return address_dict

    # Can't find address
    raise NoAddressOnInterface('No valid IPv6 found on %s.' % self.interface.name)

  def update(self):
    """Collect environmental hardware/network information."""
    self.public_ipv4_address = getPublicIPv4Address()
    self.slapos_version = version.version
    self.python_version = platform.python_version()
    self.os_type = platform.platform()

  def send(self, conf):
    """
    Send a marshalled dictionary of the compute_node object serialized via_getDict.
    """
    slap_instance = slap.slap()
    connection_dict = {}
    if conf.key_file and conf.cert_file:
      connection_dict['key_file'] = conf.key_file
      connection_dict['cert_file'] = conf.cert_file
    slap_instance.initializeConnection(conf.master_url,
                                       **connection_dict)
    slap_compute_node = slap_instance.registerComputeNode(self.reference)

    if conf.dry_run:
      return
    try:
      slap_compute_node.updateConfiguration(dumps(_getDict(self)))
    except slap.NotFoundError as error:
      raise slap.NotFoundError("%s\nERROR: This SlapOS node is not recognised by "
          "SlapOS Master and/or compute_node_id and certificates don't match. "
          "Please make sure compute_node_id of slapos.cfg looks "
          "like 'COMP-123' and is correct.\nError is : 404 Not Found." % error)

  def dump(self, path_to_xml, path_to_json, logger):
    """
    Dump the compute_node object to an xml file via xml_marshaller.

    Args:
      path_to_xml: String, path to the file to load.
      path_to_json: String, path to the JSON version to save.
    """

    # dump partition resources information
    for partition in self.partition_list:
      partition.dump()

    compute_node_dict = _getDict(self)

    if path_to_json:
      with open(path_to_json, 'w') as fout:
        json.dump(compute_node_dict, fout, sort_keys=True, indent=2)

    new_xml = dumps(compute_node_dict)
    new_pretty_xml = prettify_xml(new_xml)

    path_to_archive = path_to_xml + '.zip'

    if os.path.exists(path_to_archive) and os.path.exists(path_to_xml):
      # the archive file exists, we only backup if something has changed
      with open(path_to_xml, 'rb') as fin:
        if fin.read() == new_pretty_xml:
          # compute_node configuration did not change, nothing to write
          return

    if os.path.exists(path_to_xml):
      try:
        self.backup_xml(path_to_archive, path_to_xml)
      except:
        # might be a corrupted zip file. let's move it out of the way and retry.
        shutil.move(path_to_archive,
                    path_to_archive + time.strftime('_broken_%Y%m%d-%H:%M'))
        try:
          self.backup_xml(path_to_archive, path_to_xml)
        except:
          # give up trying
          logger.exception("Can't backup %s:", path_to_xml)

    with open(path_to_xml, 'wb') as fout:
      fout.write(new_pretty_xml)

  def backup_xml(self, path_to_archive, path_to_xml):
    """
    Stores a copy of the current xml file to an historical archive.
    """
    xml_content = open(path_to_xml).read()
    saved_filename = os.path.basename(path_to_xml) + time.strftime('.%Y%m%d-%H:%M')

    with zipfile.ZipFile(path_to_archive, 'a') as archive:
      archive.writestr(saved_filename, xml_content, zipfile.ZIP_DEFLATED)

  @classmethod
  def load(cls, path_to_xml, reference, ipv6_interface, tap_gateway_interface,
           tap_ipv6, instance_root=None, software_root=None, config=None):
    """
    Create a compute_node object from a valid xml file.

    Arg:
      path_to_xml: String, a path to a valid file containing
          a valid configuration.

    Return:
      A Compute Node object.
    """
    with open(path_to_xml, "rb") as fi:
      dumped_dict = xml_marshaller.xml_marshaller.load(fi)

    # Reconstructing the compute_node object from the xml
    compute_node = ComputeNode(
        reference=reference,
        addr=dumped_dict['address'],
        netmask=dumped_dict['netmask'],
        ipv6_interface=ipv6_interface,
        software_user=dumped_dict.get('software_user', 'slapsoft'),
        tap_gateway_interface=tap_gateway_interface,
        tap_ipv6=tap_ipv6,
        software_root=dumped_dict.get('software_root', software_root),
        instance_root=dumped_dict.get('instance_root', instance_root),
        config=config,
    )

    partition_amount = int(config.partition_amount)
    for partition_index, partition_dict in enumerate(dumped_dict['partition_list']):

      if partition_dict['user']:
        user = User(partition_dict['user']['name'])
      else:
        user = User('root')

      if partition_dict['tap']:
        tap = Tap(partition_dict['tap']['name'])
        tap.ipv4_addr = partition_dict['tap'].get('ipv4_addr', '')
        tap.ipv4_netmask = partition_dict['tap'].get('ipv4_netmask', '')
        tap.ipv4_gateway = partition_dict['tap'].get('ipv4_gateway', '')
        tap.ipv4_network = partition_dict['tap'].get('ipv4_network', '')
        tap.ipv6_addr = partition_dict['tap'].get('ipv6_addr', '')
        tap.ipv6_netmask = partition_dict['tap'].get('ipv6_netmask', '')
        tap.ipv6_gateway = partition_dict['tap'].get('ipv6_gateway', '')
        tap.ipv6_network = partition_dict['tap'].get('ipv6_network', '')
      else:
        tap = Tap(partition_dict['reference'])

      if partition_dict.get('tun') is not None and partition_dict['tun'].get('ipv4_addr') is not None:
        tun = Tun(partition_dict['tun']['name'], partition_index, partition_amount)
        tun.ipv4_addr = partition_dict['tun']['ipv4_addr']
      else:
        tun = Tun("slaptun" + str(partition_index), partition_index, partition_amount)

      address_list = partition_dict['address_list']
      external_storage_list = partition_dict.get('external_storage_list', [])

      partition = Partition(
          reference=partition_dict['reference'],
          path=partition_dict['path'],
          user=user,
          address_list=address_list,
          tap=tap,
          tun=tun if config.create_tun else None,
          external_storage_list=external_storage_list,
      )

      compute_node.partition_list.append(partition)

    return compute_node

  def _speedHackAddAllOldIpsToInterface(self):
    """
    Speed hack:
    Blindly add all IPs from existing configuration, just to speed up actual
    compute_node configuration later on.
    """
    # XXX-TODO: only add an address if it doesn't already exist.
    if self.ipv6_interface:
      interface_name = self.ipv6_interface
    elif self.interface:
      interface_name = self.interface.name
    else:
      return

    for partition in self.partition_list:
      try:
        for address in partition.address_list:
          try:
            netmask = lenNetmaskIpv6(address['netmask'])
          except:
            continue
          callAndRead(['ip', 'addr', 'add',
                       '%s/%s' % (address['addr'], netmask),
                       'dev', interface_name])
      except ValueError:
        pass

  def _addUniqueLocalAddressIpv6(self, interface_name):
    """
    Create a unique local address in the interface interface_name, so that
    slapformat can build upon this.
    See https://en.wikipedia.org/wiki/Unique_local_address.
    """
    command = 'ip address add dev %s fd00::1/64' % interface_name
    callAndRead(command.split())

  @property
  def software_gid(self):
    """Return GID for self.software_user.

    Has to be dynamic because __init__ happens before ``format`` where we
    effectively create the user and group."""
    return pwd.getpwnam(self.software_user)[3]

  def format(self, alter_user=True, alter_network=True, create_tap=True, use_unique_local_address_block=False):
    """
    Setup underlaying OS so it reflects this instance (``self``).

    - setup interfaces and addresses
    - setup TAP and TUN interfaces
    - add groups and users
    - construct partitions inside slapgrid
    """
    for path in self.instance_root, self.software_root:
      if not os.path.exists(path):
        os.makedirs(path, 0o755)
      else:
        os.chmod(path, 0o755)

    # own self.software_root by software user
    slapsoft = User(self.software_user)
    slapsoft.path = self.software_root
    if alter_user:
      slapsoft.create()
      slapsoft_pw = pwd.getpwnam(slapsoft.name)
      os.chown(slapsoft.path, slapsoft_pw.pw_uid, slapsoft_pw.pw_gid)
    os.chmod(self.software_root, 0o755)

    # Iterate over all managers and let them `format` the compute_node too
    for manager in self._manager_list:
      manager.format(self)

    # get list of instance external storage if exist
    instance_external_list = []
    if self.instance_storage_home:
      # get all /XXX/dataN where N is a digit
      data_list = glob.glob(os.path.join(self.instance_storage_home, 'data*'))
      for i in range(0, len(data_list)):
        data_path = data_list.pop()
        the_digit = os.path.basename(data_path).split('data')[-1]
        if the_digit.isdigit():
          instance_external_list.append(data_path)

    ####################
    ### Network part ###
    ####################
    if alter_network:
      if self.address is not None:
        self.interface.addIPv6Address(self.address, self.netmask)

      if use_unique_local_address_block:
        self._addUniqueLocalAddressIpv6(self.ipv6_interface or self.interface.name)

      if create_tap:
        if self.tap_gateway_interface:
          gateway_addr_dict = getIfaceAddressIPv4(self.tap_gateway_interface)
          tap_address_list = getIPv4SubnetAddressRange(gateway_addr_dict['addr'],
                                gateway_addr_dict['netmask'],
                                len(self.partition_list))
          assert(len(self.partition_list) <= len(tap_address_list))
        else:
          gateway_addr_dict = {'peer': '10.0.0.1', 'netmask': '255.255.0.0',
                               'addr': '10.0.0.1', 'network': '10.0.0.0'}
          tap_address_list = getIPv4SubnetAddressRange(gateway_addr_dict['addr'],
                                 gateway_addr_dict['netmask'],
                                 len(self.partition_list))

      self._speedHackAddAllOldIpsToInterface()

    try:
      for partition_index, partition in enumerate(self.partition_list):
        # Reconstructing User's
        partition.path = os.path.join(self.instance_root, partition.reference)
        partition.user.setPath(partition.path)
        partition.user.additional_group_list = [slapsoft.name]
        partition.external_storage_list = ['%s/%s' % (path, partition.reference)
                                            for path in instance_external_list]
        if alter_user:
          partition.user.create()

        # Reconstructing Tap and Tun
        if alter_network:
          if partition.user and partition.user.isAvailable():
            owner = partition.user
          else:
            owner = User('root')

          if create_tap:
            partition.tap.createWithOwner(owner)

            # add addresses and create route for this tap
            # Pop IP from tap_address_list and attach to tap if has no ipv4 yet
            next_ipv4_addr = '%s' % tap_address_list.pop(0)
            # skip to set this IP to tap if already exits
            if not partition.tap.ipv4_addr:
              # define new ipv4 address for this tap
              partition.tap.ipv4_addr = next_ipv4_addr
              partition.tap.ipv4_netmask = gateway_addr_dict['netmask']
              partition.tap.ipv4_gateway = gateway_addr_dict['addr']
              partition.tap.ipv4_network = gateway_addr_dict['network']

            if self.tap_ipv6:
              if not partition.tap.ipv6_addr:
                # create a new IPv6 randomly for the tap
                ipv6_dict = self.interface.addIPv6Address(tap=partition.tap)
                partition.tap.ipv6_addr = ipv6_dict['addr']
                partition.tap.ipv6_netmask = ipv6_dict['netmask']
              else:
                # make sure the tap has its IPv6
                self.interface.addIPv6Address(
                        addr=partition.tap.ipv6_addr,
                        netmask=partition.tap.ipv6_netmask,
                        tap=partition.tap)

              # construct ipv6_network (16 bit more than the compute_node network)
              netmask_len = lenNetmaskIpv6(self.interface.getGlobalScopeAddressList()[0]['netmask']) + 16
              prefix = binFromIpv6(partition.tap.ipv6_addr)[:netmask_len]
              network_addr = ipv6FromBin(prefix)
              partition.tap.ipv6_gateway = "{}1".format(network_addr) # address network::1 will be inside the VM
              partition.tap.ipv6_gateway = ipv6FromBin(binFromIpv6(partition.tap.ipv6_gateway)) # correctly format the IPv6
              partition.tap.ipv6_network = "{}/{}".format(network_addr, netmask_len)
            else:
              partition.tap.ipv6_addr = ''
              partition.tap.ipv6_netmask = ''
              partition.tap.ipv6_gateway = ''
              partition.tap.ipv6_network = ''

            # create IPv4 and IPv6 routes
            partition.tap.createRoutes()

          if partition.tun is not None:
            # create TUN interface per partition as well
            partition.tun.createWithOwner(owner)
            partition.tun.createRoutes()

        # Reconstructing partition's directory
        partition.createPath(alter_user)
        partition.createExternalPath(alter_user)

        # Reconstructing partition's address
        # There should be two addresses on each Compute Partition:
        #  * local IPv4, took from slapformat:ipv4_local_network
        #  * global IPv6
        if not partition.address_list:
          # regenerate
          partition.address_list.append(self.interface.addIPv4LocalAddress())
          partition.address_list.append(self.interface.addIPv6Address())
        elif alter_network:
          # regenerate list of addresses
          old_partition_address_list = partition.address_list
          partition.address_list = []
          if len(old_partition_address_list) != 2:
            raise ValueError(
              'There should be exactly 2 stored addresses. Got: %r' %
              (old_partition_address_list,))
          if not any(netaddr.valid_ipv6(q['addr'])
                     for q in old_partition_address_list):
            raise ValueError('Not valid ipv6 addresses loaded')
          if not any(netaddr.valid_ipv4(q['addr'])
                     for q in old_partition_address_list):
            raise ValueError('Not valid ipv6 addresses loaded')

          for address in old_partition_address_list:
            if netaddr.valid_ipv6(address['addr']):
              partition.address_list.append(self.interface.addIPv6Address(
                address['addr'],
                address['netmask']))
            elif netaddr.valid_ipv4(address['addr']):
              partition.address_list.append(self.interface.addIPv4LocalAddress(
                address['addr']))
            else:
              raise ValueError('Address %r is incorrect' % address['addr'])
    finally:
      for manager in self._manager_list:
        manager.formatTearDown(self)


class Partition(object):
  """Represent a compute partition."""

  resource_file = ".slapos-resource"

  def __init__(self, reference, path, user, address_list,
               tap, external_storage_list=[], tun=None):
    """
    Attributes:
      reference: String, the name of the partition.
      path: String, the path to the partition folder.
      user: User, the user linked to this partition.
      address_list: List of associated IP addresses.
      tap: Tap, the tap interface linked to this partition e.g. used as a gateway for kvm
      tun: Tun interface used for special apps simulating ethernet connections
      external_storage_list: Base path list of folder to format for data storage
    """

    self.reference = str(reference)
    self.path = str(path)
    self.user = user
    self.address_list = address_list or []
    self.tap = tap
    self.tun = tun
    self.external_storage_list = []

  def __getinitargs__(self):
    return (self.reference, self.path, self.user, self.address_list, self.tap, self.tun)

  def createPath(self, alter_user=True):
    """
    Create the directory of the partition, assign to the partition user and
    give it the 750 permission. In case if path exists just modifies it.
    """

    self.path = os.path.abspath(self.path)
    owner = self.user if self.user else User('root')
    if not os.path.exists(self.path):
      os.mkdir(self.path, 0o750)
    if alter_user:
      owner_pw = pwd.getpwnam(owner.name)
      os.chown(self.path, owner_pw.pw_uid, owner_pw.pw_gid)
    os.chmod(self.path, 0o750)

  def createExternalPath(self, alter_user=True):
    """
    Create and external directory of the partition, assign to the partition user
    and give it the 750 permission. In case if path exists just modifies it.
    """

    for path in self.external_storage_list:
      storage_path = os.path.abspath(path)
      owner = self.user if self.user else User('root')
      if not os.path.exists(storage_path):
        os.mkdir(storage_path, 0o750)
      if alter_user:
        owner_pw = pwd.getpwnam(owner.name)
        os.chown(storage_path, owner_pw.pw_uid, owner_pw.pw_gid)
      os.chmod(storage_path, 0o750)

  def dump(self):
    """Dump available resources into ~partition_home/.slapos-resource."""
    file_path = os.path.join(self.path, self.resource_file)
    data = _getDict(self)
    content = json.dumps(data, sort_keys=True, indent=4)
    if os.path.exists(file_path):
      with open(file_path, "r") as f:
        if f.read() == content:
          # dumped resources didn't change
          return

    with open(file_path, "w") as fo:
      fo.write(content)
    owner_pw = pwd.getpwnam(self.user.name)
    os.chmod(file_path, 0o644)
    logger.info("Partition resources saved to {}".format(
      self.reference, file_path))


class User(object):
  """User: represent and manipulate a user on the system."""

  path = None

  def __init__(self, user_name, additional_group_list=None):
    """
    Attributes:
        user_name: string, the name of the user, who will have is home in
    """
    self.name = str(user_name)
    self.shell = '/bin/sh'
    self.additional_group_list = additional_group_list

  def __getinitargs__(self):
    return (self.name,)

  def setPath(self, path):
    self.path = path

  def create(self):
    """
    Create a user on the system who will be named after the self.name with its
    own group and directory.

    Returns:
        True: if the user creation went right
    """
    # XXX: This method shall be no-op in case if all is correctly setup
    #      This method shall check if all is correctly done
    #      This method shall not reset groups, just add them
    grpname = 'grp_' + self.name if sys.platform == 'cygwin' else self.name
    try:
      grp.getgrnam(grpname)
    except KeyError:
      callAndRead(['groupadd', grpname])

    user_parameter_list = ['-d', self.path, '-g', self.name, '-s', self.shell]
    if self.additional_group_list is not None:
      user_parameter_list.extend(['-G', ','.join(self.additional_group_list)])
    user_parameter_list.append(self.name)
    try:
      pwd.getpwnam(self.name)
    except KeyError:
      user_parameter_list.append('-r')
      callAndRead(['useradd'] + user_parameter_list)
    else:
      # if the user is already created and used we should not fail
      callAndRead(['usermod'] + user_parameter_list, raise_on_error=False)
    # lock the password of user
    callAndRead(['passwd', '-l', self.name])

    return True

  def isAvailable(self):
    """
    Determine the availability of a user on the system

    Return:
        True: if available
        False: otherwise
    """

    try:
      pwd.getpwnam(self.name)
      return True
    except KeyError:
      return False


class Tap(object):
  "Tap represent a tap interface on the system"
  IFF_TAP = 0x0002
  TUNSETIFF = 0x400454ca
  KEEP_TAP_ATTACHED_EVENT = threading.Event()
  MODE = "tap"

  def __init__(self, tap_name):
    """
    Attributes:
        tap_name: String, the name of the tap interface.
        ipv4_address: String, local ipv4 to route to this tap
        ipv4_network: String, netmask to use when configure route for this tap
        ipv4_gateway: String, ipv4 of gateway to be used to reach local network
    """

    self.name = str(tap_name)
    self.ipv4_addr = ""
    self.ipv4_netmask = ""
    self.ipv4_gateway = ""
    self.ipv4_network = ""
    self.ipv6_addr = ""
    self.ipv6_netmask = ""
    self.ipv6_gateway = ""
    self.ipv6_network = ""


  def __getinitargs__(self):
    return (self.name,)

  def createWithOwner(self, owner):
    """
    Create a tap interface on the system if it doesn't exist yet.
    """
    check_file = '/sys/devices/virtual/net/%s/owner' % self.name
    owner_id = None
    if os.path.exists(check_file):
      with open(check_file) as fx:
        owner_id = fx.read().strip()
      try:
        owner_id = int(owner_id)
      except ValueError:
        owner_id = pwd.getpwnam(owner_id).pw_uid
      #
      if owner_id != pwd.getpwnam(owner.name).pw_uid:
        logger.warning("Wrong owner of TUN/TAP interface {}! Not touching it."
                       "Expected {:d} got {:d}".format(
          self.name, pwd.getpwnam(owner.name).pw_uid, owner_id))
      # if the interface already exists - don't do anything
      return

    callAndRead(['ip', 'tuntap', 'add', 'dev', self.name, 'mode',
                 self.MODE, 'user', owner.name])
    callAndRead(['ip', 'link', 'set', self.name, 'up'])

  def createRoutes(self):
    """
    Configure ipv4 and ipv6 routes
    """
    if self.ipv4_addr:
      # Check if this route exits
      code, result = callAndRead(['ip', 'route', 'show', self.ipv4_addr],
                                 raise_on_error=False)
      if code != 0 or self.ipv4_addr not in result or self.name not in result:
        callAndRead(['ip', 'route', 'add', self.ipv4_addr, 'dev', self.name])
    else:
      raise ValueError("%s should not be empty. No ipv4 address assigned to %s" %
                         (self.ipv4_addr, self.name))

    if self.ipv6_network:
      # Check if this route exits
      code, result = callAndRead(['ip', '-6', 'route', 'show', self.ipv6_gateway],
                                 raise_on_error=False)
      if code != 0 or self.name not in result:
        callAndRead(['ip', '-6', 'route', 'add', self.ipv6_gateway, 'dev', self.name])

      code, result = callAndRead(['ip', '-6', 'route', 'show', self.ipv6_network],
                                 raise_on_error=False)
      if code != 0 or 'via {}'.format(self.ipv6_gateway) not in result or 'dev {}'.format(self.name) not in result:
        if 'dev {}'.format(self.name) in result:
          callAndRead(['ip', '-6', 'route', 'del', self.ipv6_network, 'dev', self.name]) # remove old route without the "via" option
        callAndRead(['ip', '-6', 'route', 'add', self.ipv6_network, 'dev', self.name, 'via', self.ipv6_gateway])



class Tun(Tap):
  """Represent TUN interface which might be many per user."""

  MODE = "tun"
  BASE_MASK = 12
  BASE_NETWORK = "172.16.0.0"

  def __init__(self, name, sequence=None, partitions=None):
    """Create TUN interface with subnet according to the optional ``sequence`` number.

    :param name: name which will appear in ``ip list`` afterwards
    :param sequence: {int} position of this TUN among all ``partitions``
    """
    super(Tun, self).__init__(name)
    if sequence is not None:
      assert 0 <= sequence < partitions, "0 <= {} < {}".format(sequence, partitions)
      # create base IPNetwork
      ip_network = netaddr.IPNetwork(Tun.BASE_NETWORK + "/" + str(Tun.BASE_MASK))
      # compute shift in BITS to separate ``partitions`` networks into subset
      # example: for 30 partitions we need log2(30) = 8 BITS
      mask_shift = int(math.ceil(math.log(int(partitions), 2.0)))
      # IPNetwork.subnet returns iterator over all possible subnets of given mask
      ip_subnets = list(ip_network.subnet(Tun.BASE_MASK + mask_shift))
      subnet = ip_subnets[sequence]
      # For serialization purposes, convert directly to ``str``
      self.ipv4_network = str(subnet)
      self.ipv4_addr = str(subnet.ip)
      self.ipv4_netmask = str(subnet.netmask)

  def createRoutes(self):
    """Extend for physical addition of network address because TAP let this on external class."""
    if self.ipv4_network:
      # add an address
      code, _ = callAndRead(['ip', 'addr', 'add', self.ipv4_network, 'dev', self.name],
                            raise_on_error=False)
      if code == 0:
        # address added to the interface - wait
        time.sleep(1)
    else:
      raise RuntimeError("Cannot setup address on interface {}. "
                         "Address is missing.".format(self.name))
    # create routes
    super(Tun, self).createRoutes()
    # add iptables rule to accept connections from this interface
    chain_rule = ['INPUT', '-i', self.name, '-j', 'ACCEPT']
    code, _ = callAndRead(['iptables', '-C'] + chain_rule, raise_on_error=False)
    if code == 0:
      # 0 means the rule does not exits so we are free to insert it
      callAndRead(['iptables', '-I'] + chain_rule)


class Interface(object):
  """Represent a network interface on the system"""

  def __init__(self, logger, name, ipv4_local_network, ipv6_interface=None):
    """
    Attributes:
        name: String, the name of the interface
    """

    self._logger = logger
    self.name = str(name)
    self.ipv4_local_network = ipv4_local_network
    self.ipv6_interface = ipv6_interface

  # XXX no __getinitargs__, as instances of this class are never deserialized.

  def getIPv4LocalAddressList(self):
    """
    Returns currently configured local IPv4 addresses which are in
    ipv4_local_network
    """
    if not socket.AF_INET in netifaces.ifaddresses(self.name):
      return []
    return [
            {
                'addr': q['addr'],
                'netmask': q['netmask']
                }
            for q in netifaces.ifaddresses(self.name)[socket.AF_INET]
            if netaddr.IPAddress(q['addr'], 4) in netaddr.glob_to_iprange(
                netaddr.cidr_to_glob(self.ipv4_local_network))
            ]

  def getGlobalScopeAddressList(self, tap=None):
    """Returns currently configured global scope IPv6 addresses"""
    interface_name = self.ipv6_interface or self.name
    try:
      address_list = [
          q
          for q in netifaces.ifaddresses(interface_name)[socket.AF_INET6]
          if isGlobalScopeAddress(q['addr'].split('%')[0])
      ]
    except KeyError:
      raise ValueError("%s must have at least one IPv6 address assigned" %
                         interface_name)

    if tap:
      try:
        address_list += [
          q
          for q in netifaces.ifaddresses(tap.name)[socket.AF_INET6]
          if isGlobalScopeAddress(q['addr'].split('%')[0])
      ]
      except KeyError:
        pass

    if sys.platform == 'cygwin':
      for q in address_list:
        q.setdefault('netmask', 'FFFF:FFFF:FFFF:FFFF::')
    # XXX: Missing implementation of Unique Local IPv6 Unicast Addresses as
    # defined in http://www.rfc-editor.org/rfc/rfc4193.txt
    # XXX: XXX: XXX: IT IS DISALLOWED TO IMPLEMENT link-local addresses as
    # Linux and BSD are possibly wrongly implementing it -- it is "too local"
    # it is impossible to listen or access it on same node
    # XXX: IT IS DISALLOWED to implement ad hoc solution like inventing node
    # local addresses or anything which does not exists in RFC!
    return address_list

  def _addSystemAddress(self, address, netmask, ipv6=True, tap=None):
    """Adds system address to interface

    Returns True if address was added successfully.

    Returns False if there was issue.
    """

    if ipv6:
      address_string = '%s/%s' % (address, lenNetmaskIpv6(netmask))
      af = socket.AF_INET6
      interface_name = self.ipv6_interface or self.name
    else:
      af = socket.AF_INET
      address_string = '%s/%s' % (address, netmaskToPrefixIPv4(netmask))
      interface_name = self.name


    if tap:
      interface_name = tap.name
    # check if address is already took by any other interface
    for interface in netifaces.interfaces():
      if interface != interface_name:
        address_dict = netifaces.ifaddresses(interface)
        if af in address_dict:
          if address in [q['addr'].split('%')[0] for q in address_dict[af]]:
            self._logger.warning('Cannot add address %s to %s as it already exists on interface %s.' % \
                (address, interface_name, interface))
            return False

    if not af in netifaces.ifaddresses(interface_name) \
        or not address in [q['addr'].split('%')[0]
                           for q in netifaces.ifaddresses(interface_name)[af]
                           ]:
      # add an address
      callAndRead(['ip', 'addr', 'add', address_string, 'dev', interface_name])

      # Fake success for local ipv4
      if not ipv6:
        return True

      # wait few moments
      time.sleep(2)

    # Fake success for local ipv4
    if not ipv6:
      return True

    # check existence on interface for ipv6
    _, result = callAndRead(['ip', '-6', 'addr', 'list', interface_name])
    for l in result.split('\n'):
      if address in l:
        if 'tentative' in l and not tap:
          # duplicate, remove
          callAndRead(['ip', 'addr', 'del', address_string, 'dev', interface_name])
          return False
        # found and clean
        return True
    # even when added not found, this is bad...
    return False

  def _generateRandomIPv4Address(self, netmask):
    # no addresses found, generate new one
    # Try 10 times to add address, raise in case if not possible
    try_num = 10
    while try_num > 0:
      addr = random.choice([q for q in netaddr.glob_to_iprange(
        netaddr.cidr_to_glob(self.ipv4_local_network))]).format()
      if (dict(addr=addr, netmask=netmask) not in
            self.getIPv4LocalAddressList()):
        # Checking the validity of the IPv6 address
        if self._addSystemAddress(addr, netmask, False):
          return dict(addr=addr, netmask=netmask)
        try_num -= 1

    raise AddressGenerationError(addr)

  def addIPv4LocalAddress(self, addr=None):
    """Adds local IPv4 address in ipv4_local_network"""
    netmask = str(netaddr.IPNetwork(self.ipv4_local_network).netmask) if sys.platform == 'cygwin' \
             else '255.255.255.255'
    local_address_list = self.getIPv4LocalAddressList()
    if addr is None:
      return self._generateRandomIPv4Address(netmask)
    elif dict(addr=addr, netmask=netmask) not in local_address_list:
      if self._addSystemAddress(addr, netmask, False):
        return dict(addr=addr, netmask=netmask)
      else:
        self._logger.warning('Impossible to add old local IPv4 %s. Generating '
            'new IPv4 address.' % addr)
        return self._generateRandomIPv4Address(netmask)
    else:
      # confirmed to be configured
      return dict(addr=addr, netmask=netmask)

  def addIPv6Address(self, addr=None, netmask=None, tap=None):
    """
    Adds IPv6 address to interface.

    If addr is specified and exists already on interface, do nothing.

    If addr is specified and does not exist on interface, try to add given
    address. If it is not possible (ex. because network changed), calculate new
    address.

    Args:
      addr: Wished address to be added to interface.
      netmask: Wished netmask to be used.
      tap: tap interface

    Returns:
      dict(addr=address, netmask=netmask).

    Raises:
      AddressGenerationError: Couldn't construct valid address with existing
          one's on the interface.
      NoAddressOnInterface: There's no address on the interface to construct
          an address with.
    """
    interface_name = self.ipv6_interface or self.name

    # Getting one address of the interface as base of the next addresses
    interface_addr_list = self.getGlobalScopeAddressList()
    # No address found
    if len(interface_addr_list) == 0:
      raise NoAddressOnInterface(interface_name)
    address_dict = interface_addr_list[0]

    if addr is not None:
      # support netifaces which returns netmask and netmask/len
      # will result with updating the compute_node XML netmask only
      # to follow the change of netmask representation in netifaces
      if '/' in netmask:
        dict_addr_netmask_with_len = dict(addr=addr, netmask=netmask)
        dict_addr_netmask_without_len = dict(addr=addr, netmask=netmask.split('/')[0])
      else:
        dict_addr_netmask_without_len = dict(addr=addr, netmask=netmask)
        dict_addr_netmask_with_len = dict(addr=addr, netmask='%s/%s' % (netmask, lenNetmaskIpv6(netmask)))
      for dict_addr_netmask in [dict_addr_netmask_with_len, dict_addr_netmask_without_len]:
        if dict_addr_netmask in interface_addr_list or \
           (tap and dict_addr_netmask in self.getGlobalScopeAddressList(tap=tap)):
          # confirmed to be configured
          return dict_addr_netmask
      if netmask == address_dict['netmask'] or \
         (tap and lenNetmaskIpv6(netmask) == 128):
        # same netmask, so there is a chance to add good one
        interface_network = netaddr.ip.IPNetwork('%s/%s' % (address_dict['addr'],
          lenNetmaskIpv6(address_dict['netmask'])))
        requested_network = netaddr.ip.IPNetwork('%s/%s' % (addr,
          lenNetmaskIpv6(address_dict['netmask'])))
        if interface_network.network == requested_network.network:
          # same network, try to add
          if self._addSystemAddress(addr, netmask, tap=tap):
            # succeed, return it
            self._logger.info('Successfully added IPv6 %s to %s.' % (addr, tap.name or interface_name))
            return dict_addr_netmask
          else:
            self._logger.warning('Impossible to add old public IPv6 %s. '
                'Generating new IPv6 address.' % addr)

    # Try 10 times to add address, raise in case if not possible
    try_num = 10
    netmask = address_dict['netmask']
    if tap:
      netmask_len = lenNetmaskIpv6(netmask)
      prefix = binFromIpv6(address_dict['addr'])[:netmask_len]
      netmask_len += 16
      # we generate a subnetwork for the tap
      # the subnetwork has 16 bits more than the interface network
      # make sure we have at least 2 IPs in the subnetwork
      if netmask_len >= 128:
        self._logger.error('Interface %s has netmask %s which is too big for generating IPv6 on taps.' % (interface_name, netmask))
        raise AddressGenerationError(addr)
      netmask = ipv6FromBin('1'*128) # the netmask of the tap itself is always 128 bits

    while try_num > 0:
      if tap:
        addr = ipv6FromBin(prefix
          + bin(random.randint(1, 65000))[2:].zfill(16)
          + '1' * (128 - netmask_len))
      else:
        addr = ':'.join(address_dict['addr'].split(':')[:-1] + ['%x' % (
          random.randint(1, 65000), )])
        socket.inet_pton(socket.AF_INET6, addr)
      if (dict(addr=addr, netmask=netmask) not in
            self.getGlobalScopeAddressList(tap=tap)):
        # Checking the validity of the IPv6 address
        if self._addSystemAddress(addr, netmask, tap=tap):
          return dict(addr=addr, netmask=netmask)
        try_num -= 1

    raise AddressGenerationError(addr)


def parse_compute_node_definition(conf, definition_path):
  conf.logger.info('Using definition file %r' % definition_path)
  compute_node_definition = configparser.RawConfigParser({
    'software_user': 'slapsoft',
  })
  compute_node_definition.read(definition_path)
  interface = None
  address = None
  netmask = None
  if compute_node_definition.has_option('compute_node', 'address'):
    address, netmask = compute_node_definition.get('compute_node', 'address').split('/')
  if (conf.alter_network and conf.interface_name is not None
        and conf.ipv4_local_network is not None):
    interface = Interface(logger=conf.logger,
                          name=conf.interface_name,
                          ipv4_local_network=conf.ipv4_local_network,
                          ipv6_interface=conf.ipv6_interface)
  compute_node = ComputeNode(
      reference=conf.compute_node_id,
      interface=interface,
      addr=address,
      netmask=netmask,
      ipv6_interface=conf.ipv6_interface,
      software_user=compute_node_definition.get('compute_node', 'software_user'),
      tap_gateway_interface=conf.tap_gateway_interface,
      tap_ipv6=conf.tap_ipv6,
      software_root=conf.software_root,
      instance_root=conf.instance_root
  )
  partition_list = []
  for partition_number in range(int(conf.partition_amount)):
    section = 'partition_%s' % partition_number
    user = User(compute_node_definition.get(section, 'user'))
    address_list = []
    for a in compute_node_definition.get(section, 'address').split():
      address, netmask = a.split('/')
      address_list.append(dict(addr=address, netmask=netmask))
    tap = Tap(compute_node_definition.get(section, 'network_interface'))
    tun = Tun("slaptun" + str(partition_number),
              partition_number,
              int(conf.partition_amount)) if conf.create_tun else None
    partition = Partition(reference=compute_node_definition.get(section, 'pathname'),
                          path=os.path.join(conf.instance_root,
                                            compute_node_definition.get(section, 'pathname')),
                          user=user,
                          address_list=address_list,
                          tap=tap, tun=tun)
    partition_list.append(partition)
  compute_node.partition_list = partition_list
  return compute_node


def parse_compute_node_xml(conf, xml_path):
  interface = Interface(logger=conf.logger,
                        name=conf.interface_name,
                        ipv4_local_network=conf.ipv4_local_network,
                        ipv6_interface=conf.ipv6_interface)

  if os.path.exists(xml_path):
    conf.logger.debug('Loading previous compute_node data from %r' % xml_path)
    compute_node = ComputeNode.load(xml_path,
                             reference=conf.compute_node_id,
                             ipv6_interface=conf.ipv6_interface,
                             tap_gateway_interface=conf.tap_gateway_interface,
                             tap_ipv6=conf.tap_ipv6,
                             software_root=conf.software_root,
                             instance_root=conf.instance_root,
                             config=conf)
    # Connect to the interface defined by the configuration
    compute_node.interface = interface
  else:
    # If no pre-existent configuration found, create a new compute_node object
    conf.logger.warning('Creating new compute_node data with id %r', conf.compute_node_id)
    compute_node = ComputeNode(
      reference=conf.compute_node_id,
      software_root=conf.software_root,
      instance_root=conf.instance_root,
      interface=interface,
      addr=None,
      netmask=None,
      ipv6_interface=conf.ipv6_interface,
      software_user=conf.software_user,
      tap_gateway_interface=conf.tap_gateway_interface,
      tap_ipv6=conf.tap_ipv6,
      config=conf,
    )

  partition_amount = int(conf.partition_amount)
  existing_partition_amount = len(compute_node.partition_list)

  if partition_amount < existing_partition_amount:
    conf.logger.critical('Requested amount of compute partitions (%s) is lower '
                         'than already configured (%s), cannot continue',
                         partition_amount, existing_partition_amount)
    sys.exit(1)
  elif partition_amount > existing_partition_amount:
    conf.logger.info('Adding %s new partitions',
                     partition_amount - existing_partition_amount)

  for i in range(existing_partition_amount, partition_amount):
    # add new partitions
    partition = Partition(
        reference='%s%s' % (conf.partition_base_name, i),
        path=os.path.join(conf.instance_root, '%s%s' % (
          conf.partition_base_name, i)),
        user=User('%s%s' % (conf.user_base_name, i)),
        address_list=None,
        tap=Tap('%s%s' % (conf.tap_base_name, i)),
        tun=Tun('slaptun' + str(i), i, partition_amount) if conf.create_tun else None
    )
    compute_node.partition_list.append(partition)

  return compute_node


def write_compute_node_definition(conf, compute_node):
  compute_node_definition = configparser.RawConfigParser()
  compute_node_definition.add_section('compute_node')
  if compute_node.address is not None and compute_node.netmask is not None:
    compute_node_definition.set('compute_node', 'address', '/'.join(
      [compute_node.address, compute_node.netmask]))
  for partition_number, partition in enumerate(compute_node.partition_list):
    section = 'partition_%s' % partition_number
    compute_node_definition.add_section(section)
    address_list = []
    for address in partition.address_list:
      address_list.append('/'.join([address['addr'], address['netmask']]))
    compute_node_definition.set(section, 'address', ' '.join(address_list))
    compute_node_definition.set(section, 'user', partition.user.name)
    compute_node_definition.set(section, 'network_interface', partition.tap.name)
    compute_node_definition.set(section, 'pathname', partition.reference)
  compute_node_definition.write(open(conf.output_definition_file, 'w'))
  conf.logger.info('Stored compute_node definition in %r' % conf.output_definition_file)


def random_delay(conf):
  # Add delay between 0 and 1 hour
  # XXX should be the contrary: now by default, and cron should have
  # --maximal-delay=3600
  if not conf.now:
    duration = float(60 * 60) * random.random()
    conf.logger.info('Sleeping for %s seconds. To disable this feature, '
                     'use with --now parameter in manual.' % duration)
    time.sleep(duration)


def do_format(conf):
  random_delay(conf)

  if conf.input_definition_file:
    compute_node = parse_compute_node_definition(conf, conf.input_definition_file)
  else:
    # no definition file, figure out compute_node
    compute_node = parse_compute_node_xml(conf, conf.compute_node_xml)

  compute_node.instance_storage_home = conf.instance_storage_home
  conf.logger.info('Updating compute_node')
  address = compute_node.getAddress()
  compute_node.address = address['addr']
  compute_node.netmask = address['netmask']

  if conf.output_definition_file:
    write_compute_node_definition(conf, compute_node)

  compute_node.format(alter_user=conf.alter_user,
                     alter_network=conf.alter_network,
                     create_tap=conf.create_tap,
                     use_unique_local_address_block=conf.use_unique_local_address_block)

  if getattr(conf, 'certificate_repository_path', None):
    mkdir_p(conf.certificate_repository_path, mode=0o700)

  compute_node.update()
  # Dumping and sending to the erp5 the current configuration
  if not conf.dry_run:
    compute_node.dump(path_to_xml=conf.compute_node_xml,
                  path_to_json=conf.compute_node_json,
                  logger=conf.logger)
  conf.logger.info('Posting information to %r' % conf.master_url)
  compute_node.send(conf)
  conf.logger.info('slapos successfully prepared the compute_node.')


class FormatConfig(object):
  """This class represents the options for slapos node format
  all the attributes of this class are options
  all the attributes can be modified by config file (.cfg)
  some attributes can be modified by command line"""

  # Network options
  alter_network = 'True' # modifiable by cmdline
  interface_name = None
  ipv6_interface = None
  create_tap = True
  create_tun = False
  tap_base_name = None
  tap_ipv6 = True
  tap_gateway_interface = ''
  ipv4_local_network = None
  use_unique_local_address_block = False

  # User options
  alter_user = 'True' # modifiable by cmdline
  software_user = 'slapsoft'
  instance_storage_home = None
  partition_base_name = None
  user_base_name = None

  # Other options
  input_definition_file = None  # modifiable by cmdline
  compute_node_xml = None           # modifiable by cmdline
  compute_node_json = None          # modifiable by cmdline
  log_file = None               # modifiable by cmdline
  output_definition_file = None # modifiable by cmdline
  dry_run = None                # modifiable by cmdline
  key_file = None
  cert_file = None

  def __init__(self, logger):
    self.logger = logger

  @staticmethod
  def checkRequiredBinary(binary_list):
    missing_binary_list = []
    for b in binary_list:
      if type(b) is not list:
        b = [b]
      try:
        callAndRead(b)
      except ValueError:
        pass
      except OSError:
        missing_binary_list.append(b[0])
    if missing_binary_list:
      raise UsageError('Some required binaries are missing or not '
          'functional: %s' % (','.join(missing_binary_list), ))

  def mergeConfig(self, args, configp):
    """
    Set options given by config files and arguments.
    Must be executed before setting up the logger.
    """
    # First, the configuration file options erase the default class options
    for section in ("slapformat", "slapos"):
      self.__dict__.update(configp.items(section))

    # Second, the command line arguments erase the configuration file options
    self.__dict__.update(args.__dict__)

  def setConfig(self):
    # deprecated options raise an error
    for option in ['bridge_name', 'no_bridge']:
      if getattr(self, option, None):
        message = 'Option %r is totally deprecated, please update your config file' % (option)
        self.logger.error(message)
        raise UsageError(message)

    # Convert strings to booleans
    for option in ['alter_network', 'alter_user', 'create_tap', 'create_tun', 'use_unique_local_address_block', 'tap_ipv6']:
      attr = getattr(self, option)
      if isinstance(attr, str):
        if attr.lower() == 'true':
          root_needed = True
          setattr(self, option, True)
        elif attr.lower() == 'false':
          setattr(self, option, False)
        else:
          message = 'Option %r needs to be "True" or "False", wrong value: ' \
              '%r' % (option, getattr(self, option))
          self.logger.error(message)
          raise UsageError(message)

    if not self.dry_run:
      if self.alter_user:
        self.checkRequiredBinary(['groupadd', 'useradd', 'usermod', ['passwd', '-h']])
      if self.create_tap or self.alter_network:
        self.checkRequiredBinary(['ip'])

    # Check mandatory options
    for parameter in ('compute_node_id', 'instance_root', 'master_url',
                      'software_root', 'compute_node_xml'):
      if not getattr(self, parameter, None):
        raise UsageError("Parameter '%s' is not defined." % parameter)

    # Check existence of SSL certificate files, if defined
    for attribute in ['key_file', 'cert_file', 'master_ca_file']:
      file_location = getattr(self, attribute, None)
      if file_location is not None:
        if not os.path.exists(file_location):
          self.logger.fatal('File %r does not exist or is not readable.' %
              file_location)
          sys.exit(1)

    self.logger.debug('Started.')
    if self.dry_run:
      self.logger.info("Dry-run mode enabled.")
    if self.create_tap:
      self.logger.info("Tap creation mode enabled (%s IPv6).", "with" if self.tap_ipv6 else "without")

    # Calculate path once
    self.compute_node_xml = os.path.abspath(self.compute_node_xml)

    if self.input_definition_file:
      self.input_definition_file = os.path.abspath(self.input_definition_file)

    if self.output_definition_file:
      self.output_definition_file = os.path.abspath(self.output_definition_file)


tracing_monkeypatch_mark = []
def tracing_monkeypatch(conf):
  """Substitute os module and callAndRead function with tracing wrappers."""

  # This function is called again if "slapos node boot" failed.
  # Don't wrap the logging method again, otherwise the output becomes double.
  if tracing_monkeypatch_mark:
    return

  global os
  global callAndRead

  real_callAndRead = callAndRead

  os = OS(conf)
  if conf.dry_run:
    def dry_callAndRead(argument_list, raise_on_error=True):
      return 0, ''
    callAndRead = dry_callAndRead

    def fake_getpwnam(user):
      class result(object):
        pw_uid = 12345
        pw_gid = 54321
      return result
    pwd.getpwnam = fake_getpwnam
  else:
    dry_callAndRead = real_callAndRead

  def logging_callAndRead(argument_list, raise_on_error=True):
    conf.logger.debug(' '.join(argument_list))
    return dry_callAndRead(argument_list, raise_on_error)
  callAndRead = logging_callAndRead

  # Put a mark. This function was called once.
  tracing_monkeypatch_mark.append(None)
