#!/usr/bin/python
#

# Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 Google Inc.
#
# 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 2 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., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.


"""Tool to upgrade the configuration file.

This code handles only the types supported by simplejson. As an
example, 'set' is a 'list'.

"""


import os
import os.path
import sys
import optparse
import logging
import time
from cStringIO import StringIO

from ganeti import constants
from ganeti import serializer
from ganeti import utils
from ganeti import cli
from ganeti import bootstrap
from ganeti import config
from ganeti import netutils
from ganeti import pathutils


options = None
args = None


#: Target major version we will upgrade to
TARGET_MAJOR = 2
#: Target minor version we will upgrade to
TARGET_MINOR = 9
#: Target major version for downgrade
DOWNGRADE_MAJOR = 2
#: Target minor version for downgrade
DOWNGRADE_MINOR = 8

# map of legacy device types
# (mapping differing old LD_* constants to new DT_* constants)
DEV_TYPE_OLD_NEW = {"lvm": constants.DT_PLAIN, "drbd8": constants.DT_DRBD8}
# (mapping differing new DT_* constants to old LD_* constants)
DEV_TYPE_NEW_OLD = dict((v, k) for k, v in DEV_TYPE_OLD_NEW.items())


class Error(Exception):
  """Generic exception"""
  pass


def SetupLogging():
  """Configures the logging module.

  """
  formatter = logging.Formatter("%(asctime)s: %(message)s")

  stderr_handler = logging.StreamHandler()
  stderr_handler.setFormatter(formatter)
  if options.debug:
    stderr_handler.setLevel(logging.NOTSET)
  elif options.verbose:
    stderr_handler.setLevel(logging.INFO)
  else:
    stderr_handler.setLevel(logging.WARNING)

  root_logger = logging.getLogger("")
  root_logger.setLevel(logging.NOTSET)
  root_logger.addHandler(stderr_handler)


def CheckHostname(path):
  """Ensures hostname matches ssconf value.

  @param path: Path to ssconf file

  """
  ssconf_master_node = utils.ReadOneLineFile(path)
  hostname = netutils.GetHostname().name

  if ssconf_master_node == hostname:
    return True

  logging.warning("Warning: ssconf says master node is '%s', but this"
                  " machine's name is '%s'; this tool must be run on"
                  " the master node", ssconf_master_node, hostname)
  return False


def _FillIPolicySpecs(default_ipolicy, ipolicy):
  if "minmax" in ipolicy:
    for (key, spec) in ipolicy["minmax"][0].items():
      for (par, val) in default_ipolicy["minmax"][0][key].items():
        if par not in spec:
          spec[par] = val


def UpgradeIPolicy(ipolicy, default_ipolicy, isgroup):
  minmax_keys = ["min", "max"]
  if any((k in ipolicy) for k in minmax_keys):
    minmax = {}
    for key in minmax_keys:
      if key in ipolicy:
        if ipolicy[key]:
          minmax[key] = ipolicy[key]
        del ipolicy[key]
    if minmax:
      ipolicy["minmax"] = [minmax]
  if isgroup and "std" in ipolicy:
    del ipolicy["std"]
  _FillIPolicySpecs(default_ipolicy, ipolicy)


def UpgradeNetworks(config_data):
  networks = config_data.get("networks", None)
  if not networks:
    config_data["networks"] = {}


def UpgradeCluster(config_data):
  cluster = config_data.get("cluster", None)
  if cluster is None:
    raise Error("Cannot find cluster")
  ipolicy = cluster.setdefault("ipolicy", None)
  if ipolicy:
    UpgradeIPolicy(ipolicy, constants.IPOLICY_DEFAULTS, False)


def UpgradeGroups(config_data):
  cl_ipolicy = config_data["cluster"].get("ipolicy")
  for group in config_data["nodegroups"].values():
    networks = group.get("networks", None)
    if not networks:
      group["networks"] = {}
    ipolicy = group.get("ipolicy", None)
    if ipolicy:
      if cl_ipolicy is None:
        raise Error("A group defines an instance policy but there is no"
                    " instance policy at cluster level")
      UpgradeIPolicy(ipolicy, cl_ipolicy, True)


def GetExclusiveStorageValue(config_data):
  """Return a conservative value of the exclusive_storage flag.

  Return C{True} if the cluster or at least a nodegroup have the flag set.

  """
  ret = False
  cluster = config_data["cluster"]
  ndparams = cluster.get("ndparams")
  if ndparams is not None and ndparams.get("exclusive_storage"):
    ret = True
  for group in config_data["nodegroups"].values():
    ndparams = group.get("ndparams")
    if ndparams is not None and ndparams.get("exclusive_storage"):
      ret = True
  return ret


def ChangeDiskDevType(disk, dev_type_map):
  """Replaces disk's dev_type attributes according to the given map.

  This can be used for both, up or downgrading the disks.
  """
  if disk["dev_type"] in dev_type_map:
    disk["dev_type"] = dev_type_map[disk["dev_type"]]
  if "children" in disk:
    for child in disk["children"]:
      ChangeDiskDevType(child, dev_type_map)


def UpgradeDiskDevType(disk):
  """Upgrades the disks' device type."""
  ChangeDiskDevType(disk, DEV_TYPE_OLD_NEW)


def UpgradeInstances(config_data):
  """Upgrades the instances' configuration."""

  network2uuid = dict((n["name"], n["uuid"])
                      for n in config_data["networks"].values())
  if "instances" not in config_data:
    raise Error("Can't find the 'instances' key in the configuration!")

  missing_spindles = False
  for instance, iobj in config_data["instances"].items():
    for nic in iobj["nics"]:
      name = nic.get("network", None)
      if name:
        uuid = network2uuid.get(name, None)
        if uuid:
          print("NIC with network name %s found."
                " Substituting with uuid %s." % (name, uuid))
          nic["network"] = uuid

    if "disks" not in iobj:
      raise Error("Instance '%s' doesn't have a disks entry?!" % instance)
    disks = iobj["disks"]
    for idx, dobj in enumerate(disks):
      expected = "disk/%s" % idx
      current = dobj.get("iv_name", "")
      if current != expected:
        logging.warning("Updating iv_name for instance %s/disk %s"
                        " from '%s' to '%s'",
                        instance, idx, current, expected)
        dobj["iv_name"] = expected

      if "dev_type" in dobj:
        UpgradeDiskDevType(dobj)

      if not "spindles" in dobj:
        missing_spindles = True

  if GetExclusiveStorageValue(config_data) and missing_spindles:
    # We cannot be sure that the instances that are missing spindles have
    # exclusive storage enabled (the check would be more complicated), so we
    # give a noncommittal message
    logging.warning("Some instance disks could be needing to update the"
                    " spindles parameter; you can check by running"
                    " 'gnt-cluster verify', and fix any problem with"
                    " 'gnt-cluster repair-disk-sizes'")


def UpgradeRapiUsers():
  if (os.path.isfile(options.RAPI_USERS_FILE_PRE24) and
      not os.path.islink(options.RAPI_USERS_FILE_PRE24)):
    if os.path.exists(options.RAPI_USERS_FILE):
      raise Error("Found pre-2.4 RAPI users file at %s, but another file"
                  " already exists at %s" %
                  (options.RAPI_USERS_FILE_PRE24, options.RAPI_USERS_FILE))
    logging.info("Found pre-2.4 RAPI users file at %s, renaming to %s",
                 options.RAPI_USERS_FILE_PRE24, options.RAPI_USERS_FILE)
    if not options.dry_run:
      utils.RenameFile(options.RAPI_USERS_FILE_PRE24, options.RAPI_USERS_FILE,
                       mkdir=True, mkdir_mode=0750)

  # Create a symlink for RAPI users file
  if (not (os.path.islink(options.RAPI_USERS_FILE_PRE24) or
           os.path.isfile(options.RAPI_USERS_FILE_PRE24)) and
      os.path.isfile(options.RAPI_USERS_FILE)):
    logging.info("Creating symlink from %s to %s",
                 options.RAPI_USERS_FILE_PRE24, options.RAPI_USERS_FILE)
    if not options.dry_run:
      os.symlink(options.RAPI_USERS_FILE, options.RAPI_USERS_FILE_PRE24)


def UpgradeWatcher():
  # Remove old watcher state file if it exists
  if os.path.exists(options.WATCHER_STATEFILE):
    logging.info("Removing watcher state file %s", options.WATCHER_STATEFILE)
    if not options.dry_run:
      utils.RemoveFile(options.WATCHER_STATEFILE)


def UpgradeFileStoragePaths(config_data):
  # Write file storage paths
  if not os.path.exists(options.FILE_STORAGE_PATHS_FILE):
    cluster = config_data["cluster"]
    file_storage_dir = cluster.get("file_storage_dir")
    shared_file_storage_dir = cluster.get("shared_file_storage_dir")
    del cluster

    logging.info("Ganeti 2.7 and later only allow whitelisted directories"
                 " for file storage; writing existing configuration values"
                 " into '%s'",
                 options.FILE_STORAGE_PATHS_FILE)

    if file_storage_dir:
      logging.info("File storage directory: %s", file_storage_dir)
    if shared_file_storage_dir:
      logging.info("Shared file storage directory: %s",
                   shared_file_storage_dir)

    buf = StringIO()
    buf.write("# List automatically generated from configuration by\n")
    buf.write("# cfgupgrade at %s\n" % time.asctime())
    if file_storage_dir:
      buf.write("%s\n" % file_storage_dir)
    if shared_file_storage_dir:
      buf.write("%s\n" % shared_file_storage_dir)
    utils.WriteFile(file_name=options.FILE_STORAGE_PATHS_FILE,
                    data=buf.getvalue(),
                    mode=0600,
                    dry_run=options.dry_run,
                    backup=True)


def GetNewNodeIndex(nodes_by_old_key, old_key, new_key_field):
  if old_key not in nodes_by_old_key:
    logging.warning("Can't find node '%s' in configuration, assuming that it's"
                    " already up-to-date", old_key)
    return old_key
  return nodes_by_old_key[old_key][new_key_field]


def ChangeNodeIndices(config_data, old_key_field, new_key_field):
  def ChangeDiskNodeIndices(disk):
    # Note: 'drbd8' is a legacy device type from pre 2.9 and needs to be
    # considered when up/downgrading from/to any versions touching 2.9 on the
    # way.
    drbd_disk_types = set(["drbd8"]) | constants.DTS_DRBD
    if disk["dev_type"] in drbd_disk_types:
      for i in range(0, 2):
        disk["logical_id"][i] = GetNewNodeIndex(nodes_by_old_key,
                                                disk["logical_id"][i],
                                                new_key_field)
    if "children" in disk:
      for child in disk["children"]:
        ChangeDiskNodeIndices(child)

  nodes_by_old_key = {}
  nodes_by_new_key = {}
  for (_, node) in config_data["nodes"].items():
    nodes_by_old_key[node[old_key_field]] = node
    nodes_by_new_key[node[new_key_field]] = node

  config_data["nodes"] = nodes_by_new_key

  cluster = config_data["cluster"]
  cluster["master_node"] = GetNewNodeIndex(nodes_by_old_key,
                                           cluster["master_node"],
                                           new_key_field)

  for inst in config_data["instances"].values():
    inst["primary_node"] = GetNewNodeIndex(nodes_by_old_key,
                                           inst["primary_node"],
                                           new_key_field)
    for disk in inst["disks"]:
      ChangeDiskNodeIndices(disk)


def ChangeInstanceIndices(config_data, old_key_field, new_key_field):
  insts_by_old_key = {}
  insts_by_new_key = {}
  for (_, inst) in config_data["instances"].items():
    insts_by_old_key[inst[old_key_field]] = inst
    insts_by_new_key[inst[new_key_field]] = inst

  config_data["instances"] = insts_by_new_key


def UpgradeNodeIndices(config_data):
  ChangeNodeIndices(config_data, "name", "uuid")


def UpgradeInstanceIndices(config_data):
  ChangeInstanceIndices(config_data, "name", "uuid")


def UpgradeAll(config_data):
  config_data["version"] = constants.BuildVersion(TARGET_MAJOR,
                                                  TARGET_MINOR, 0)
  UpgradeRapiUsers()
  UpgradeWatcher()
  UpgradeFileStoragePaths(config_data)
  UpgradeNetworks(config_data)
  UpgradeCluster(config_data)
  UpgradeGroups(config_data)
  UpgradeInstances(config_data)
  UpgradeNodeIndices(config_data)
  UpgradeInstanceIndices(config_data)


def DowngradeDiskDevType(disk):
  """Downgrades the disks' device type."""
  ChangeDiskDevType(disk, DEV_TYPE_NEW_OLD)


def DowngradeDisks(disks, owner):
  for disk in disks:
    # Remove spindles to downgrade to 2.8
    if "spindles" in disk:
      logging.warning("Removing spindles (value=%s) from disk %s (%s) of"
                      " instance %s",
                      disk["spindles"], disk["iv_name"], disk["uuid"], owner)
      del disk["spindles"]
    if "dev_type" in disk:
      DowngradeDiskDevType(disk)


def DowngradeInstances(config_data):
  if "instances" not in config_data:
    raise Error("Cannot find the 'instances' key in the configuration!")
  for (iname, iobj) in config_data["instances"].items():
    if "disks" not in iobj:
      raise Error("Cannot find 'disks' key for instance %s" % iname)
    DowngradeDisks(iobj["disks"], iname)


def DowngradeNodeIndices(config_data):
  ChangeNodeIndices(config_data, "uuid", "name")


def DowngradeInstanceIndices(config_data):
  ChangeInstanceIndices(config_data, "uuid", "name")


def DowngradeHvparams(config_data):
  """Downgrade the cluster's hypervisor parameters."""
  cluster = config_data["cluster"]
  if "hvparams" in cluster:
    hvparams = cluster["hvparams"]
    xen_params = None
    for xen_variant in [constants.HT_XEN_PVM, constants.HT_XEN_HVM]:
      if xen_variant in hvparams:
        xen_params = hvparams[xen_variant]
        # 'xen_cmd' was introduced in 2.9
        if constants.HV_XEN_CMD in xen_params:
          del xen_params[constants.HV_XEN_CMD]
        # 'vif_script' was introducted in 2.9
        if constants.HV_VIF_SCRIPT in xen_params:
          del xen_params[constants.HV_VIF_SCRIPT]


def DowngradeAll(config_data):
  # Any code specific to a particular version should be labeled that way, so
  # it can be removed when updating to the next version.
  config_data["version"] = constants.BuildVersion(DOWNGRADE_MAJOR,
                                                  DOWNGRADE_MINOR, 0)
  DowngradeInstances(config_data)
  DowngradeNodeIndices(config_data)
  DowngradeInstanceIndices(config_data)
  DowngradeHvparams(config_data)


def main():
  """Main program.

  """
  global options, args # pylint: disable=W0603

  # Option parsing
  parser = optparse.OptionParser(usage="%prog [--debug|--verbose] [--force]")
  parser.add_option("--dry-run", dest="dry_run",
                    action="store_true",
                    help="Try to do the conversion, but don't write"
                         " output file")
  parser.add_option(cli.FORCE_OPT)
  parser.add_option(cli.DEBUG_OPT)
  parser.add_option(cli.VERBOSE_OPT)
  parser.add_option("--ignore-hostname", dest="ignore_hostname",
                    action="store_true", default=False,
                    help="Don't abort if hostname doesn't match")
  parser.add_option("--path", help="Convert configuration in this"
                    " directory instead of '%s'" % pathutils.DATA_DIR,
                    default=pathutils.DATA_DIR, dest="data_dir")
  parser.add_option("--confdir",
                    help=("Use this directory instead of '%s'" %
                          pathutils.CONF_DIR),
                    default=pathutils.CONF_DIR, dest="conf_dir")
  parser.add_option("--no-verify",
                    help="Do not verify configuration after upgrade",
                    action="store_true", dest="no_verify", default=False)
  parser.add_option("--downgrade",
                    help="Downgrade to the previous stable version",
                    action="store_true", dest="downgrade", default=False)
  (options, args) = parser.parse_args()

  # We need to keep filenames locally because they might be renamed between
  # versions.
  options.data_dir = os.path.abspath(options.data_dir)
  options.CONFIG_DATA_PATH = options.data_dir + "/config.data"
  options.SERVER_PEM_PATH = options.data_dir + "/server.pem"
  options.KNOWN_HOSTS_PATH = options.data_dir + "/known_hosts"
  options.RAPI_CERT_FILE = options.data_dir + "/rapi.pem"
  options.SPICE_CERT_FILE = options.data_dir + "/spice.pem"
  options.SPICE_CACERT_FILE = options.data_dir + "/spice-ca.pem"
  options.RAPI_USERS_FILE = options.data_dir + "/rapi/users"
  options.RAPI_USERS_FILE_PRE24 = options.data_dir + "/rapi_users"
  options.CONFD_HMAC_KEY = options.data_dir + "/hmac.key"
  options.CDS_FILE = options.data_dir + "/cluster-domain-secret"
  options.SSCONF_MASTER_NODE = options.data_dir + "/ssconf_master_node"
  options.WATCHER_STATEFILE = options.data_dir + "/watcher.data"
  options.FILE_STORAGE_PATHS_FILE = options.conf_dir + "/file-storage-paths"

  SetupLogging()

  # Option checking
  if args:
    raise Error("No arguments expected")
  if options.downgrade and not options.no_verify:
    options.no_verify = True

  # Check master name
  if not (CheckHostname(options.SSCONF_MASTER_NODE) or options.ignore_hostname):
    logging.error("Aborting due to hostname mismatch")
    sys.exit(constants.EXIT_FAILURE)

  if not options.force:
    if options.downgrade:
      usertext = ("The configuration is going to be DOWNGRADED to version %s.%s"
                  " Some configuration data might be removed if they don't fit"
                  " in the old format. Please make sure you have read the"
                  " upgrade notes (available in the UPGRADE file and included"
                  " in other documentation formats) to understand what they"
                  " are. Continue with *DOWNGRADING* the configuration?" %
                  (DOWNGRADE_MAJOR, DOWNGRADE_MINOR))
    else:
      usertext = ("Please make sure you have read the upgrade notes for"
                  " Ganeti %s (available in the UPGRADE file and included"
                  " in other documentation formats). Continue with upgrading"
                  " configuration?" % constants.RELEASE_VERSION)
    if not cli.AskUser(usertext):
      sys.exit(constants.EXIT_FAILURE)

  # Check whether it's a Ganeti configuration directory
  if not (os.path.isfile(options.CONFIG_DATA_PATH) and
          os.path.isfile(options.SERVER_PEM_PATH) and
          os.path.isfile(options.KNOWN_HOSTS_PATH)):
    raise Error(("%s does not seem to be a Ganeti configuration"
                 " directory") % options.data_dir)

  if not os.path.isdir(options.conf_dir):
    raise Error("Not a directory: %s" % options.conf_dir)

  config_data = serializer.LoadJson(utils.ReadFile(options.CONFIG_DATA_PATH))

  try:
    config_version = config_data["version"]
  except KeyError:
    raise Error("Unable to determine configuration version")

  (config_major, config_minor, config_revision) = \
    constants.SplitVersion(config_version)

  logging.info("Found configuration version %s (%d.%d.%d)",
               config_version, config_major, config_minor, config_revision)

  if "config_version" in config_data["cluster"]:
    raise Error("Inconsistent configuration: found config_version in"
                " configuration file")

  # Downgrade to the previous stable version
  if options.downgrade:
    if not ((config_major == TARGET_MAJOR and config_minor == TARGET_MINOR) or
            (config_major == DOWNGRADE_MAJOR and
             config_minor == DOWNGRADE_MINOR)):
      raise Error("Downgrade supported only from the latest version (%s.%s),"
                  " found %s (%s.%s.%s) instead" %
                  (TARGET_MAJOR, TARGET_MINOR, config_version, config_major,
                   config_minor, config_revision))
    DowngradeAll(config_data)

  # Upgrade from 2.{0..7} to 2.9
  elif config_major == 2 and config_minor in range(0, 10):
    if config_revision != 0:
      logging.warning("Config revision is %s, not 0", config_revision)
    UpgradeAll(config_data)

  elif config_major == TARGET_MAJOR and config_minor == TARGET_MINOR:
    logging.info("No changes necessary")

  else:
    raise Error("Configuration version %d.%d.%d not supported by this tool" %
                (config_major, config_minor, config_revision))

  try:
    logging.info("Writing configuration file to %s", options.CONFIG_DATA_PATH)
    utils.WriteFile(file_name=options.CONFIG_DATA_PATH,
                    data=serializer.DumpJson(config_data),
                    mode=0600,
                    dry_run=options.dry_run,
                    backup=True)

    if not options.dry_run:
      bootstrap.GenerateClusterCrypto(
        False, False, False, False, False,
        nodecert_file=options.SERVER_PEM_PATH,
        rapicert_file=options.RAPI_CERT_FILE,
        spicecert_file=options.SPICE_CERT_FILE,
        spicecacert_file=options.SPICE_CACERT_FILE,
        hmackey_file=options.CONFD_HMAC_KEY,
        cds_file=options.CDS_FILE)

  except Exception:
    logging.critical("Writing configuration failed. It is probably in an"
                     " inconsistent state and needs manual intervention.")
    raise

  # test loading the config file
  all_ok = True
  if not (options.dry_run or options.no_verify):
    logging.info("Testing the new config file...")
    cfg = config.ConfigWriter(cfg_file=options.CONFIG_DATA_PATH,
                              accept_foreign=options.ignore_hostname,
                              offline=True)
    # if we reached this, it's all fine
    vrfy = cfg.VerifyConfig()
    if vrfy:
      logging.error("Errors after conversion:")
      for item in vrfy:
        logging.error(" - %s", item)
      all_ok = False
    else:
      logging.info("File loaded successfully after upgrading")
    del cfg

  if options.downgrade:
    action = "downgraded"
    out_ver = "%s.%s" % (DOWNGRADE_MAJOR, DOWNGRADE_MINOR)
  else:
    action = "upgraded"
    out_ver = constants.RELEASE_VERSION
  if all_ok:
    cli.ToStderr("Configuration successfully %s to version %s.",
                 action, out_ver)
  else:
    cli.ToStderr("Configuration %s to version %s, but there are errors."
                 "\nPlease review the file.", action, out_ver)


if __name__ == "__main__":
  main()