#!/usr/bin/python
#

# Copyright (C) 2007, 2008, 2009 Google Inc.
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# modification, are permitted provided that the following conditions are
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# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
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# 2. Redistributions in binary form must reproduce the above copyright
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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# pylint: disable=C0103,E1103

# C0103: invalid name NoDefault
# E1103: Instance of 'foor' has no 'bar' member (but some types could
# not be inferred)


"""Tool to upgrade the configuration file.

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

@note: this has lots of duplicate content with C{cfgupgrade}. Ideally, it
should be merged.

"""


import os
import os.path
import sys
import optparse
import logging
import errno

from ganeti import constants
from ganeti import serializer
from ganeti import utils
from ganeti import cli
from ganeti import pathutils

from ganeti.utils import version


options = None
args = None

# Unique object to identify calls without default value
NoDefault = object()

# Dictionary with instance old keys, and new hypervisor keys
INST_HV_CHG = {
  "hvm_pae": constants.HV_PAE,
  "vnc_bind_address": constants.HV_VNC_BIND_ADDRESS,
  "initrd_path": constants.HV_INITRD_PATH,
  "hvm_nic_type": constants.HV_NIC_TYPE,
  "kernel_path": constants.HV_KERNEL_PATH,
  "hvm_acpi": constants.HV_ACPI,
  "hvm_cdrom_image_path": constants.HV_CDROM_IMAGE_PATH,
  "hvm_boot_order": constants.HV_BOOT_ORDER,
  "hvm_disk_type": constants.HV_DISK_TYPE,
  }

# Instance beparams changes
INST_BE_CHG = {
  "vcpus": constants.BE_VCPUS,
  "memory": constants.BE_MEMORY,
  "auto_balance": constants.BE_AUTO_BALANCE,
  }

# Field names
F_SERIAL = "serial_no"


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


def SsconfName(key):
  """Returns the file name of an (old) ssconf key.

  """
  return "%s/ssconf_%s" % (options.data_dir, key)


def ReadFile(file_name, default=NoDefault):
  """Reads a file.

  """
  logging.debug("Reading %s", file_name)
  try:
    fh = open(file_name, "r")
  except IOError, err:
    if default is not NoDefault and err.errno == errno.ENOENT:
      return default
    raise

  try:
    return fh.read()
  finally:
    fh.close()


def WriteFile(file_name, data):
  """Writes a configuration file.

  """
  logging.debug("Writing %s", file_name)
  utils.WriteFile(file_name=file_name, data=data, mode=0600,
                  dry_run=options.dry_run, backup=True)


def GenerateSecret(all_secrets):
  """Generate an unique DRBD secret.

  This is a copy from ConfigWriter.

  """
  retries = 64
  while retries > 0:
    secret = utils.GenerateSecret()
    if secret not in all_secrets:
      break
    retries -= 1
  else:
    raise Error("Can't generate unique DRBD secret")
  return secret


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.CRITICAL)

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


def Cluster12To20(cluster):
  """Upgrades the cluster object from 1.2 to 2.0.

  """
  logging.info("Upgrading the cluster object")
  # Upgrade the configuration version
  if "config_version" in cluster:
    del cluster["config_version"]

  # Add old ssconf keys back to config
  logging.info(" - importing ssconf keys")
  for key in ("master_node", "master_ip", "master_netdev", "cluster_name"):
    if key not in cluster:
      cluster[key] = ReadFile(SsconfName(key)).strip()

  if "default_hypervisor" not in cluster:
    old_hyp = ReadFile(SsconfName("hypervisor")).strip()
    if old_hyp == "xen-3.0":
      hyp = "xen-pvm"
    elif old_hyp == "xen-hvm-3.1":
      hyp = "xen-hvm"
    elif old_hyp == "fake":
      hyp = "fake"
    else:
      raise Error("Unknown old hypervisor name '%s'" % old_hyp)

    logging.info("Setting the default and enabled hypervisor")
    cluster["default_hypervisor"] = hyp
    cluster["enabled_hypervisors"] = [hyp]

  # hv/be params
  if "hvparams" not in cluster:
    logging.info(" - adding hvparams")
    cluster["hvparams"] = constants.HVC_DEFAULTS
  if "beparams" not in cluster:
    logging.info(" - adding beparams")
    cluster["beparams"] = {constants.PP_DEFAULT: constants.BEC_DEFAULTS}

  # file storage
  if "file_storage_dir" not in cluster:
    cluster["file_storage_dir"] = pathutils.DEFAULT_FILE_STORAGE_DIR

  # candidate pool size
  if "candidate_pool_size" not in cluster:
    cluster["candidate_pool_size"] = constants.MASTER_POOL_SIZE_DEFAULT


def Node12To20(node):
  """Upgrades a node from 1.2 to 2.0.

  """
  logging.info("Upgrading node %s", node['name'])
  if F_SERIAL not in node:
    node[F_SERIAL] = 1
  if "master_candidate" not in node:
    node["master_candidate"] = True
  for key in "offline", "drained":
    if key not in node:
      node[key] = False


def Instance12To20(drbd_minors, secrets, hypervisor, instance):
  """Upgrades an instance from 1.2 to 2.0.

  """
  if F_SERIAL not in instance:
    instance[F_SERIAL] = 1

  if "hypervisor" not in instance:
    instance["hypervisor"] = hypervisor

  # hvparams changes
  if "hvparams" not in instance:
    instance["hvparams"] = hvp = {}
  for old, new in INST_HV_CHG.items():
    if old in instance:
      if (instance[old] is not None and
          instance[old] != constants.VALUE_DEFAULT and # no longer valid in 2.0
          new in constants.HVC_DEFAULTS[hypervisor]):
        hvp[new] = instance[old]
      del instance[old]

  # beparams changes
  if "beparams" not in instance:
    instance["beparams"] = bep = {}
  for old, new in INST_BE_CHG.items():
    if old in instance:
      if instance[old] is not None:
        bep[new] = instance[old]
      del instance[old]

  # disk changes
  for disk in instance["disks"]:
    Disk12To20(drbd_minors, secrets, disk)

  # other instance changes
  if "status" in instance:
    instance["admin_up"] = instance["status"] == "up"
    del instance["status"]


def Disk12To20(drbd_minors, secrets, disk):
  """Upgrades a disk from 1.2 to 2.0.

  """
  if "mode" not in disk:
    disk["mode"] = constants.DISK_RDWR
  if disk["dev_type"] == constants.DT_DRBD8:
    old_lid = disk["logical_id"]
    for node in old_lid[:2]:
      if node not in drbd_minors:
        raise Error("Can't find node '%s' while upgrading disk" % node)
      drbd_minors[node] += 1
      minor = drbd_minors[node]
      old_lid.append(minor)
    old_lid.append(GenerateSecret(secrets))
    del disk["physical_id"]
  if disk["children"]:
    for child in disk["children"]:
      Disk12To20(drbd_minors, secrets, child)


def _ParseOptions():
  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("--path", help="Convert configuration in this"
                    " directory instead of '%s'" % pathutils.DATA_DIR,
                    default=pathutils.DATA_DIR, dest="data_dir")
  return parser.parse_args()


def _ComposePaths(oobj):
  # We need to keep filenames locally because they might be renamed between
  # versions.
  oobj.data_dir = os.path.abspath(oobj.data_dir)
  oobj.CONFIG_DATA_PATH = oobj.data_dir + "/config.data"
  oobj.SERVER_PEM_PATH = oobj.data_dir + "/server.pem"
  oobj.KNOWN_HOSTS_PATH = oobj.data_dir + "/known_hosts"
  oobj.RAPI_CERT_FILE = oobj.data_dir + "/rapi.pem"


def _WriteConfiguration(config_data, known_hosts):
  try:
    logging.info("Writing configuration file")
    WriteFile(options.CONFIG_DATA_PATH, serializer.DumpJson(config_data))

    if known_hosts is not None:
      logging.info("Writing SSH known_hosts file (%s)", known_hosts.strip())
      WriteFile(options.KNOWN_HOSTS_PATH, known_hosts)

    if not options.dry_run:
      if not os.path.exists(options.RAPI_CERT_FILE):
        logging.debug("Writing RAPI certificate to %s", options.RAPI_CERT_FILE)
        utils.GenerateSelfSignedSslCert(options.RAPI_CERT_FILE, 1)

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

  logging.info("Configuration file updated.")


def main():
  """Main program.

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

  program = os.path.basename(sys.argv[0])

  (options, args) = _ParseOptions()
  _ComposePaths(options)

  SetupLogging()

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

  if not options.force:
    usertext = ("%s MUST be run on the master node. Is this the master"
                " node and are ALL instances down?" % program)
    if not cli.AskUser(usertext):
      sys.exit(1)

  # 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) or
          os.path.isfile(options.KNOWN_HOSTS_PATH)):
    raise Error(("%s does not seem to be a known Ganeti configuration"
                 " directory") % options.data_dir)

  config_version = ReadFile(SsconfName("config_version"), "1.2").strip()
  logging.info("Found configuration version %s", config_version)

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

  # Ganeti 1.2?
  if config_version == "1.2":
    logging.info("Found a Ganeti 1.2 configuration")

    cluster = config_data["cluster"]

    old_config_version = cluster.get("config_version", None)
    logging.info("Found old configuration version %s", old_config_version)
    if old_config_version not in (3, ):
      raise Error("Unsupported configuration version: %s" %
                  old_config_version)
    if "version" not in config_data:
      config_data["version"] = version.BuildVersion(2, 0, 0)
    if F_SERIAL not in config_data:
      config_data[F_SERIAL] = 1

    # Make sure no instance uses remote_raid1 anymore
    remote_raid1_instances = []
    for instance in config_data["instances"].values():
      if instance["disk_template"] == "remote_raid1":
        remote_raid1_instances.append(instance["name"])
    if remote_raid1_instances:
      for name in remote_raid1_instances:
        logging.error("Instance %s still using remote_raid1 disk template",
                      name)
      raise Error("Unable to convert configuration as long as there are"
                  " instances using remote_raid1 disk template")

    # Build content of new known_hosts file
    cluster_name = ReadFile(SsconfName("cluster_name")).rstrip()
    cluster_key = cluster["rsahostkeypub"]
    known_hosts = "%s ssh-rsa %s\n" % (cluster_name, cluster_key)

    Cluster12To20(cluster)

    # Add node attributes
    logging.info("Upgrading nodes")
    # stable-sort the names to have repeatable runs
    for node_name in utils.NiceSort(config_data["nodes"].keys()):
      Node12To20(config_data["nodes"][node_name])

    # Instance changes
    logging.info("Upgrading instances")
    drbd_minors = dict.fromkeys(config_data["nodes"], 0)
    secrets = set()
    # stable-sort the names to have repeatable runs
    for instance_name in utils.NiceSort(config_data["instances"].keys()):
      Instance12To20(drbd_minors, secrets, cluster["default_hypervisor"],
                     config_data["instances"][instance_name])

  else:
    logging.info("Found a Ganeti 2.0 configuration")

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

    known_hosts = None

  _WriteConfiguration(config_data, known_hosts)


if __name__ == "__main__":
  main()