#!/usr/bin/python
#

# Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012 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

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


options = None
args = None


#: Target major version we will upgrade to
TARGET_MAJOR = 2
#: Target minor version we will upgrade to
TARGET_MINOR = 6


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 UpgradeInstances(config_data):
  for instance in config_data["instances"].values():
    hotplug_info = instance.get("hotplug_info", None)
    if hotplug_info:
      try:
        del hotplug_info["pci_pool"]
      except:
        pass


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'" % constants.DATA_DIR,
                    default=constants.DATA_DIR, dest="data_dir")
  parser.add_option("--no-verify",
                    help="Do not verify configuration after upgrade",
                    action="store_true", dest="no_verify", 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"

  SetupLogging()

  # Option checking
  if args:
    raise Error("No arguments expected")

  # 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:
    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)

  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")

  # Upgrade from 2.0/2.1/2.2/2.3 to 2.4
  if config_major == 2 and config_minor in (0, 1, 2, 3, 4, 5):
    if config_revision != 0:
      logging.warning("Config revision is %s, not 0", config_revision)

    config_data["version"] = constants.BuildVersion(TARGET_MAJOR,
                                                    TARGET_MINOR, 0)

    if "instances" not in config_data:
      raise Error("Can't find the 'instances' key in the configuration!")
    for instance, iobj in config_data["instances"].items():
      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

  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))

  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)

  # 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)

  UpgradeInstances(config_data)

  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
  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)
    del cfg
    logging.info("File loaded successfully")

  cli.ToStderr("Configuration successfully upgraded for version %s.",
               constants.RELEASE_VERSION)


if __name__ == "__main__":
  main()