Synnefo » snf-ganeti

#

#

# Copyright (C) 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.

"""Script to prepare a node for joining a cluster.

"""

import os

import os.path

import optparse

import sys

import logging

import errno

import OpenSSL

from ganeti import cli

from ganeti import constants

from ganeti import errors

from ganeti import pathutils

from ganeti import utils

from ganeti import serializer

from ganeti import ht

from ganeti import ssh

from ganeti import ssconf

_SSH_KEY_LIST_ITEM = \

  ht.TAnd(ht.TIsLength(3),

          ht.TItems([

            ht.TElemOf(constants.SSHK_ALL),

            ht.Comment("public")(ht.TNonEmptyString),

            ht.Comment("private")(ht.TNonEmptyString),

          ]))

_SSH_KEY_LIST = ht.TListOf(_SSH_KEY_LIST_ITEM)

_DATA_CHECK = ht.TStrictDict(False, True, {

  constants.SSHS_CLUSTER_NAME: ht.TNonEmptyString,

  constants.SSHS_NODE_DAEMON_CERTIFICATE: ht.TNonEmptyString,

  constants.SSHS_SSH_HOST_KEY: _SSH_KEY_LIST,

  constants.SSHS_SSH_ROOT_KEY: _SSH_KEY_LIST,

  })

_SSH_DAEMON_KEYFILES = {

  constants.SSHK_RSA:

    (pathutils.SSH_HOST_RSA_PUB, pathutils.SSH_HOST_RSA_PRIV),

  constants.SSHK_DSA:

    (pathutils.SSH_HOST_DSA_PUB, pathutils.SSH_HOST_DSA_PRIV),

  }

class JoinError(errors.GenericError):

  """Local class for reporting errors.

  """

def ParseOptions():

  """Parses the options passed to the program.

  @return: Options and arguments

  """

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

  parser = optparse.OptionParser(usage="%prog [--dry-run]",

                                 prog=program)

  parser.add_option(cli.DEBUG_OPT)

  parser.add_option(cli.VERBOSE_OPT)

  parser.add_option(cli.DRY_RUN_OPT)

  (opts, args) = parser.parse_args()

  return VerifyOptions(parser, opts, args)

def VerifyOptions(parser, opts, args):

  """Verifies options and arguments for correctness.

  """

  if args:

    parser.error("No arguments are expected")

  return opts

def SetupLogging(opts):

  """Configures the logging module.

  """

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

  stderr_handler = logging.StreamHandler()

  stderr_handler.setFormatter(formatter)

  if opts.debug:

    stderr_handler.setLevel(logging.NOTSET)

  elif opts.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 _VerifyCertificate(cert, _noded_cert_file=pathutils.NODED_CERT_FILE):

  """Verifies a certificate against the local node daemon certificate.

  @type cert: string

  @param cert: Certificate in PEM format (no key)

  """

  try:

    OpenSSL.crypto.load_privatekey(OpenSSL.crypto.FILETYPE_PEM, cert)

  except OpenSSL.crypto.Error, err:

    pass

  else:

    raise JoinError("No private key may be given")

  try:

    cert = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM, cert)

  except Exception, err:

    raise errors.X509CertError("(stdin)",

                               "Unable to load certificate: %s" % err)

  try:

    noded_pem = utils.ReadFile(_noded_cert_file)

  except EnvironmentError, err:

    if err.errno != errno.ENOENT:

      raise

    logging.debug("Local node certificate was not found (file %s)",

                  _noded_cert_file)

    return

  try:

    key = OpenSSL.crypto.load_privatekey(OpenSSL.crypto.FILETYPE_PEM, noded_pem)

  except Exception, err:

    raise errors.X509CertError(_noded_cert_file,

                               "Unable to load private key: %s" % err)

  ctx = OpenSSL.SSL.Context(OpenSSL.SSL.TLSv1_METHOD)

  ctx.use_privatekey(key)

  ctx.use_certificate(cert)

  try:

    ctx.check_privatekey()

  except OpenSSL.SSL.Error:

    raise JoinError("Given cluster certificate does not match local key")

def VerifyCertificate(data, _verify_fn=_VerifyCertificate):

  """Verifies cluster certificate.

  @type data: dict

  """

  cert = data.get(constants.SSHS_NODE_DAEMON_CERTIFICATE)

  if cert:

    _verify_fn(cert)

def _VerifyClusterName(name, _ss_cluster_name_file=None):

  """Verifies cluster name against a local cluster name.

  @type name: string

  @param name: Cluster name

  """

  if _ss_cluster_name_file is None:

    _ss_cluster_name_file = \

      ssconf.SimpleStore().KeyToFilename(constants.SS_CLUSTER_NAME)

  try:

    local_name = utils.ReadOneLineFile(_ss_cluster_name_file)

  except EnvironmentError, err:

    if err.errno != errno.ENOENT:

      raise

    logging.debug("Local cluster name was not found (file %s)",

                  _ss_cluster_name_file)

  else:

    if name != local_name:

      raise JoinError("Current cluster name is '%s'" % local_name)

def VerifyClusterName(data, _verify_fn=_VerifyClusterName):

  """Verifies cluster name.

  @type data: dict

  """

  name = data.get(constants.SSHS_CLUSTER_NAME)

  if name:

    _verify_fn(name)

  else:

    raise JoinError("Cluster name must be specified")

def _UpdateKeyFiles(keys, dry_run, keyfiles):

  """Updates SSH key files.

  @type keys: sequence of tuple; (string, string, string)

  @param keys: Keys to write, tuples consist of key type

    (L{constants.SSHK_ALL}), public and private key

  @type dry_run: boolean

  @param dry_run: Whether to perform a dry run

  @type keyfiles: dict; (string as key, tuple with (string, string) as values)

  @param keyfiles: Mapping from key types (L{constants.SSHK_ALL}) to file

    names; value tuples consist of public key filename and private key filename

  """

  assert set(keyfiles) == constants.SSHK_ALL

  for (kind, public_key, private_key) in keys:

    (public_file, private_file) = keyfiles[kind]

    logging.debug("Writing %s ...", public_file)

    utils.WriteFile(public_file, data=public_key, mode=0644,

                    backup=True, dry_run=dry_run)

    logging.debug("Writing %s ...", private_file)

    utils.WriteFile(private_file, data=private_key, mode=0600,

                    backup=True, dry_run=dry_run)

def UpdateSshDaemon(data, dry_run, _runcmd_fn=utils.RunCmd,

                    _keyfiles=None):

  """Updates SSH daemon's keys.

  Unless C{dry_run} is set, the daemon is restarted at the end.

  @type data: dict

  @param data: Input data

  @type dry_run: boolean

  @param dry_run: Whether to perform a dry run

  """

  keys = data.get(constants.SSHS_SSH_HOST_KEY)

  if not keys:

    return

  if _keyfiles is None:

    _keyfiles = _SSH_DAEMON_KEYFILES

  logging.info("Updating SSH daemon key files")

  _UpdateKeyFiles(keys, dry_run, _keyfiles)

  if dry_run:

    logging.info("This is a dry run, not restarting SSH daemon")

  else:

    result = _runcmd_fn([pathutils.DAEMON_UTIL, "reload-ssh-keys"],

                        interactive=True)

    if result.failed:

      raise JoinError("Could not reload SSH keys, command '%s'"

                      " had exitcode %s and error %s" %

                       (result.cmd, result.exit_code, result.output))

def UpdateSshRoot(data, dry_run, _homedir_fn=None):

  """Updates root's SSH keys.

  Root's C{authorized_keys} file is also updated with new public keys.

  @type data: dict

  @param data: Input data

  @type dry_run: boolean

  @param dry_run: Whether to perform a dry run

  """

  keys = data.get(constants.SSHS_SSH_ROOT_KEY)

  if not keys:

    return

  (dsa_private_file, dsa_public_file, auth_keys_file) = \

    ssh.GetUserFiles(constants.SSH_LOGIN_USER, mkdir=True,

                     kind=constants.SSHK_DSA, _homedir_fn=_homedir_fn)

  (rsa_private_file, rsa_public_file, _) = \

    ssh.GetUserFiles(constants.SSH_LOGIN_USER, mkdir=True,

                     kind=constants.SSHK_RSA, _homedir_fn=_homedir_fn)

  _UpdateKeyFiles(keys, dry_run, {

    constants.SSHK_RSA: (rsa_public_file, rsa_private_file),

    constants.SSHK_DSA: (dsa_public_file, dsa_private_file),

    })

  if dry_run:

    logging.info("This is a dry run, not modifying %s", auth_keys_file)

  else:

    for (_, _, public_key) in keys:

      utils.AddAuthorizedKey(auth_keys_file, public_key)

def LoadData(raw):

  """Parses and verifies input data.

  @rtype: dict

  """

  try:

    data = serializer.LoadJson(raw)

  except Exception, err:

    raise errors.ParseError("Can't parse input data: %s" % err)

  if not _DATA_CHECK(data):

    raise errors.ParseError("Input data does not match expected format: %s" %

                            _DATA_CHECK)

  return data

def Main():

  """Main routine.

  """

  opts = ParseOptions()

  SetupLogging(opts)

  try:

    data = LoadData(sys.stdin.read())

    # Check if input data is correct

    VerifyClusterName(data)

    VerifyCertificate(data)

    # Update SSH files

    UpdateSshDaemon(data, opts.dry_run)

    UpdateSshRoot(data, opts.dry_run)

    logging.info("Setup finished successfully")

  except Exception, err: # pylint: disable=W0703

    logging.debug("Caught unhandled exception", exc_info=True)

    (retcode, message) = cli.FormatError(err)

    logging.error(message)

    return retcode

  else:

    return constants.EXIT_SUCCESS