Synnefo » snf-ganeti

#

#

# Copyright (C) 2010 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.

"""Ganeti RAPI client."""

# No Ganeti-specific modules should be imported. The RAPI client is supposed to

# be standalone.

import sys

import httplib

import urllib2

import logging

import simplejson

import socket

import urllib

import OpenSSL

import distutils.version

GANETI_RAPI_PORT = 5080

GANETI_RAPI_VERSION = 2

HTTP_DELETE = "DELETE"

HTTP_GET = "GET"

HTTP_PUT = "PUT"

HTTP_POST = "POST"

HTTP_OK = 200

HTTP_NOT_FOUND = 404

HTTP_APP_JSON = "application/json"

REPLACE_DISK_PRI = "replace_on_primary"

REPLACE_DISK_SECONDARY = "replace_on_secondary"

REPLACE_DISK_CHG = "replace_new_secondary"

REPLACE_DISK_AUTO = "replace_auto"

NODE_ROLE_DRAINED = "drained"

NODE_ROLE_MASTER_CANDIATE = "master-candidate"

NODE_ROLE_MASTER = "master"

NODE_ROLE_OFFLINE = "offline"

NODE_ROLE_REGULAR = "regular"

# Internal constants

_REQ_DATA_VERSION_FIELD = "__version__"

_INST_CREATE_REQV1 = "instance-create-reqv1"

_INST_NIC_PARAMS = frozenset(["mac", "ip", "mode", "link", "bridge"])

_INST_CREATE_V0_DISK_PARAMS = frozenset(["size"])

_INST_CREATE_V0_PARAMS = frozenset([

  "os", "pnode", "snode", "iallocator", "start", "ip_check", "name_check",

  "hypervisor", "file_storage_dir", "file_driver", "dry_run",

  ])

_INST_CREATE_V0_DPARAMS = frozenset(["beparams", "hvparams"])

class Error(Exception):

  """Base error class for this module.

  """

  pass

class CertificateError(Error):

  """Raised when a problem is found with the SSL certificate.

  """

  pass

class GanetiApiError(Error):

  """Generic error raised from Ganeti API.

  """

  def __init__(self, msg, code=None):

    Error.__init__(self, msg)

    self.code = code

def FormatX509Name(x509_name):

  """Formats an X509 name.

  @type x509_name: OpenSSL.crypto.X509Name

  """

  try:

    # Only supported in pyOpenSSL 0.7 and above

    get_components_fn = x509_name.get_components

  except AttributeError:

    return repr(x509_name)

  else:

    return "".join("/%s=%s" % (name, value)

                   for name, value in get_components_fn())

class CertAuthorityVerify:

  """Certificate verificator for SSL context.

  Configures SSL context to verify server's certificate.

  """

  _CAPATH_MINVERSION = "0.9"

  _DEFVFYPATHS_MINVERSION = "0.9"

  _PYOPENSSL_VERSION = OpenSSL.__version__

  _PARSED_PYOPENSSL_VERSION = distutils.version.LooseVersion(_PYOPENSSL_VERSION)

  _SUPPORT_CAPATH = (_PARSED_PYOPENSSL_VERSION >= _CAPATH_MINVERSION)

  _SUPPORT_DEFVFYPATHS = (_PARSED_PYOPENSSL_VERSION >= _DEFVFYPATHS_MINVERSION)

  def __init__(self, cafile=None, capath=None, use_default_verify_paths=False):

    """Initializes this class.

    @type cafile: string

    @param cafile: In which file we can find the certificates

    @type capath: string

    @param capath: In which directory we can find the certificates

    @type use_default_verify_paths: bool

    @param use_default_verify_paths: Whether the platform provided CA

                                     certificates are to be used for

                                     verification purposes

    """

    self._cafile = cafile

    self._capath = capath

    self._use_default_verify_paths = use_default_verify_paths

    if self._capath is not None and not self._SUPPORT_CAPATH:

      raise Error(("PyOpenSSL %s has no support for a CA directory,"

                   " version %s or above is required") %

                  (self._PYOPENSSL_VERSION, self._CAPATH_MINVERSION))

    if self._use_default_verify_paths and not self._SUPPORT_DEFVFYPATHS:

      raise Error(("PyOpenSSL %s has no support for using default verification"

                   " paths, version %s or above is required") %

                  (self._PYOPENSSL_VERSION, self._DEFVFYPATHS_MINVERSION))

  @staticmethod

  def _VerifySslCertCb(logger, _, cert, errnum, errdepth, ok):

    """Callback for SSL certificate verification.

    @param logger: Logging object

    """

    if ok:

      log_fn = logger.debug

    else:

      log_fn = logger.error

    log_fn("Verifying SSL certificate at depth %s, subject '%s', issuer '%s'",

           errdepth, FormatX509Name(cert.get_subject()),

           FormatX509Name(cert.get_issuer()))

    if not ok:

      try:

        # Only supported in pyOpenSSL 0.7 and above

        # pylint: disable-msg=E1101

        fn = OpenSSL.crypto.X509_verify_cert_error_string

      except AttributeError:

        errmsg = ""

      else:

        errmsg = ":%s" % fn(errnum)

      logger.error("verify error:num=%s%s", errnum, errmsg)

    return ok

  def __call__(self, ctx, logger):

    """Configures an SSL context to verify certificates.

    @type ctx: OpenSSL.SSL.Context

    @param ctx: SSL context

    """

    if self._use_default_verify_paths:

      ctx.set_default_verify_paths()

    if self._cafile or self._capath:

      if self._SUPPORT_CAPATH:

        ctx.load_verify_locations(self._cafile, self._capath)

      else:

        ctx.load_verify_locations(self._cafile)

    ctx.set_verify(OpenSSL.SSL.VERIFY_PEER,

                   lambda conn, cert, errnum, errdepth, ok: \

                     self._VerifySslCertCb(logger, conn, cert,

                                           errnum, errdepth, ok))

class _HTTPSConnectionOpenSSL(httplib.HTTPSConnection):

  """HTTPS Connection handler that verifies the SSL certificate.

  """

  # Python before version 2.6 had its own httplib.FakeSocket wrapper for

  # sockets

  _SUPPORT_FAKESOCKET = (sys.hexversion < 0x2060000)

  def __init__(self, *args, **kwargs):

    """Initializes this class.

    """

    httplib.HTTPSConnection.__init__(self, *args, **kwargs)

    self._logger = None

    self._config_ssl_verification = None

  def Setup(self, logger, config_ssl_verification):

    """Sets the SSL verification config function.

    @param logger: Logging object

    @type config_ssl_verification: callable

    """

    assert self._logger is None

    assert self._config_ssl_verification is None

    self._logger = logger

    self._config_ssl_verification = config_ssl_verification

  def connect(self):

    """Connect to the server specified when the object was created.

    This ensures that SSL certificates are verified.

    """

    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

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

    ctx.set_options(OpenSSL.SSL.OP_NO_SSLv2)

    if self._config_ssl_verification:

      self._config_ssl_verification(ctx, self._logger)

    ssl = OpenSSL.SSL.Connection(ctx, sock)

    ssl.connect((self.host, self.port))

    if self._SUPPORT_FAKESOCKET:

      self.sock = httplib.FakeSocket(sock, ssl)

    else:

      self.sock = _SslSocketWrapper(ssl)

class _SslSocketWrapper(object):

  def __init__(self, sock):

    """Initializes this class.

    """

    self._sock = sock

  def __getattr__(self, name):

    """Forward everything to underlying socket.

    """

    return getattr(self._sock, name)

  def makefile(self, mode, bufsize):

    """Fake makefile method.

    makefile() on normal file descriptors uses dup2(2), which doesn't work with

    SSL sockets and therefore is not implemented by pyOpenSSL. This fake method

    works with the httplib module, but might not work for other modules.

    """

    # pylint: disable-msg=W0212

    return socket._fileobject(self._sock, mode, bufsize)

class _HTTPSHandler(urllib2.HTTPSHandler):

  def __init__(self, logger, config_ssl_verification):

    """Initializes this class.

    @param logger: Logging object

    @type config_ssl_verification: callable

    @param config_ssl_verification: Function to configure SSL context for

                                    certificate verification

    """

    urllib2.HTTPSHandler.__init__(self)

    self._logger = logger

    self._config_ssl_verification = config_ssl_verification

  def _CreateHttpsConnection(self, *args, **kwargs):

    """Wrapper around L{_HTTPSConnectionOpenSSL} to add SSL verification.

    This wrapper is necessary provide a compatible API to urllib2.

    """

    conn = _HTTPSConnectionOpenSSL(*args, **kwargs)

    conn.Setup(self._logger, self._config_ssl_verification)

    return conn

  def https_open(self, req):

    """Creates HTTPS connection.

    Called by urllib2.

    """

    return self.do_open(self._CreateHttpsConnection, req)

class _RapiRequest(urllib2.Request):

  def __init__(self, method, url, headers, data):

    """Initializes this class.

    """

    urllib2.Request.__init__(self, url, data=data, headers=headers)

    self._method = method

  def get_method(self):

    """Returns the HTTP request method.

    """

    return self._method

class GanetiRapiClient(object):

  """Ganeti RAPI client.

  """

  USER_AGENT = "Ganeti RAPI Client"

  _json_encoder = simplejson.JSONEncoder(sort_keys=True)

  def __init__(self, host, port=GANETI_RAPI_PORT,

               username=None, password=None,

               config_ssl_verification=None, ignore_proxy=False,

               logger=logging):

    """Constructor.

    @type host: string

    @param host: the ganeti cluster master to interact with

    @type port: int

    @param port: the port on which the RAPI is running (default is 5080)

    @type username: string

    @param username: the username to connect with

    @type password: string

    @param password: the password to connect with

    @type config_ssl_verification: callable

    @param config_ssl_verification: Function to configure SSL context for

                                    certificate verification

    @type ignore_proxy: bool

    @param ignore_proxy: Whether to ignore proxy settings

    @param logger: Logging object

    """

    self._host = host

    self._port = port

    self._logger = logger

    self._base_url = "https://%s:%s" % (host, port)

    handlers = [_HTTPSHandler(self._logger, config_ssl_verification)]

    self._httpauthhandler = None

    if username is not None:

      pwmgr = urllib2.HTTPPasswordMgrWithDefaultRealm()

      pwmgr.add_password(None, self._base_url, username, password)

      self._httpauthhandler = urllib2.HTTPBasicAuthHandler(pwmgr)

      handlers.append(self._httpauthhandler)

    elif password:

      raise Error("Specified password without username")

    if ignore_proxy:

      handlers.append(urllib2.ProxyHandler({}))

    self._http = urllib2.build_opener(*handlers) # pylint: disable-msg=W0142

    self._headers = {

      "Accept": HTTP_APP_JSON,

      "Content-type": HTTP_APP_JSON,

      "User-Agent": self.USER_AGENT,

      }

  @staticmethod

  def _EncodeQuery(query):

    """Encode query values for RAPI URL.

    @type query: list of two-tuples

    @param query: Query arguments

    @rtype: list

    @return: Query list with encoded values

    """

    result = []

    for name, value in query:

      if value is None:

        result.append((name, ""))

      elif isinstance(value, bool):

        # Boolean values must be encoded as 0 or 1

        result.append((name, int(value)))

      elif isinstance(value, (list, tuple, dict)):

        raise ValueError("Invalid query data type %r" % type(value).__name__)

      else:

        result.append((name, value))

    return result

  def _SendRequest(self, method, path, query, content):

    """Sends an HTTP request.

    This constructs a full URL, encodes and decodes HTTP bodies, and

    handles invalid responses in a pythonic way.

    @type method: string

    @param method: HTTP method to use

    @type path: string

    @param path: HTTP URL path

    @type query: list of two-tuples

    @param query: query arguments to pass to urllib.urlencode

    @type content: str or None

    @param content: HTTP body content

    @rtype: str

    @return: JSON-Decoded response

    @raises CertificateError: If an invalid SSL certificate is found

    @raises GanetiApiError: If an invalid response is returned

    """

    assert path.startswith("/")

    if content:

      encoded_content = self._json_encoder.encode(content)

    else:

      encoded_content = None

    # Build URL

    urlparts = [self._base_url, path]

    if query:

      urlparts.append("?")

      urlparts.append(urllib.urlencode(self._EncodeQuery(query)))

    url = "".join(urlparts)

    self._logger.debug("Sending request %s %s to %s:%s"

                       " (headers=%r, content=%r)",

                       method, url, self._host, self._port, self._headers,

                       encoded_content)

    req = _RapiRequest(method, url, self._headers, encoded_content)

    try:

      resp = self._http.open(req)

      encoded_response_content = resp.read()

      # Workaround for python 2.6: reset the retried count of the http handler,

      # or it'll fail after ~5 requests made with the same client. Under python

      # 2.4 and 2.5 this variable is not used.

      if self._httpauthhandler is not None:

        self._httpauthhandler.retried = 0

    except (OpenSSL.SSL.Error, OpenSSL.crypto.Error), err:

      raise CertificateError("SSL issue: %s (%r)" % (err, err))

    except urllib2.HTTPError, err:

      raise GanetiApiError(str(err), code=err.code)

    except urllib2.URLError, err:

      raise GanetiApiError(str(err))

    if encoded_response_content:

      response_content = simplejson.loads(encoded_response_content)

    else:

      response_content = None

    # TODO: Are there other status codes that are valid? (redirect?)

    if resp.code != HTTP_OK:

      if isinstance(response_content, dict):

        msg = ("%s %s: %s" %

               (response_content["code"],

                response_content["message"],

                response_content["explain"]))

      else:

        msg = str(response_content)

      raise GanetiApiError(msg, code=resp.code)

    return response_content

  def GetVersion(self):

    """Gets the Remote API version running on the cluster.

    @rtype: int

    @return: Ganeti Remote API version

    """

    return self._SendRequest(HTTP_GET, "/version", None, None)

  def GetFeatures(self):

    """Gets the list of optional features supported by RAPI server.

    @rtype: list

    @return: List of optional features

    """

    try:

      return self._SendRequest(HTTP_GET, "/%s/features" % GANETI_RAPI_VERSION,

                               None, None)

    except GanetiApiError, err:

      # Older RAPI servers don't support this resource

      if err.code == HTTP_NOT_FOUND:

        return []

      raise

  def GetOperatingSystems(self):

    """Gets the Operating Systems running in the Ganeti cluster.

    @rtype: list of str

    @return: operating systems

    """

    return self._SendRequest(HTTP_GET, "/%s/os" % GANETI_RAPI_VERSION,

                             None, None)

  def GetInfo(self):

    """Gets info about the cluster.

    @rtype: dict

    @return: information about the cluster

    """

    return self._SendRequest(HTTP_GET, "/%s/info" % GANETI_RAPI_VERSION,

                             None, None)

  def GetClusterTags(self):

    """Gets the cluster tags.

    @rtype: list of str

    @return: cluster tags

    """

    return self._SendRequest(HTTP_GET, "/%s/tags" % GANETI_RAPI_VERSION,

                             None, None)

  def AddClusterTags(self, tags, dry_run=False):

    """Adds tags to the cluster.

    @type tags: list of str

    @param tags: tags to add to the cluster

    @type dry_run: bool

    @param dry_run: whether to perform a dry run

    @rtype: int

    @return: job id

    """

    query = [("tag", t) for t in tags]

    if dry_run:

      query.append(("dry-run", 1))

    return self._SendRequest(HTTP_PUT, "/%s/tags" % GANETI_RAPI_VERSION,

                             query, None)

  def DeleteClusterTags(self, tags, dry_run=False):

    """Deletes tags from the cluster.

    @type tags: list of str

    @param tags: tags to delete

    @type dry_run: bool

    @param dry_run: whether to perform a dry run

    """

    query = [("tag", t) for t in tags]

    if dry_run:

      query.append(("dry-run", 1))

    return self._SendRequest(HTTP_DELETE, "/%s/tags" % GANETI_RAPI_VERSION,

                             query, None)

  def GetInstances(self, bulk=False):

    """Gets information about instances on the cluster.

    @type bulk: bool

    @param bulk: whether to return all information about all instances

    @rtype: list of dict or list of str

    @return: if bulk is True, info about the instances, else a list of instances

    """

    query = []

    if bulk:

      query.append(("bulk", 1))

    instances = self._SendRequest(HTTP_GET,

                                  "/%s/instances" % GANETI_RAPI_VERSION,

                                  query, None)

    if bulk:

      return instances

    else:

      return [i["id"] for i in instances]

  def GetInstance(self, instance):

    """Gets information about an instance.

    @type instance: str

    @param instance: instance whose info to return

    @rtype: dict

    @return: info about the instance

    """

    return self._SendRequest(HTTP_GET,

                             ("/%s/instances/%s" %

                              (GANETI_RAPI_VERSION, instance)), None, None)

  def GetInstanceInfo(self, instance, static=None):

    """Gets information about an instance.

    @type instance: string

    @param instance: Instance name

    @rtype: string

    @return: Job ID

    """

    if static is not None:

      query = [("static", static)]

    else:

      query = None

    return self._SendRequest(HTTP_GET,

                             ("/%s/instances/%s/info" %

                              (GANETI_RAPI_VERSION, instance)), query, None)

  def CreateInstance(self, mode, name, disk_template, disks, nics,

                     **kwargs):

    """Creates a new instance.

    More details for parameters can be found in the RAPI documentation.

    @type mode: string

    @param mode: Instance creation mode

    @type name: string

    @param name: Hostname of the instance to create

    @type disk_template: string

    @param disk_template: Disk template for instance (e.g. plain, diskless,

                          file, or drbd)

    @type disks: list of dicts

    @param disks: List of disk definitions

    @type nics: list of dicts

    @param nics: List of NIC definitions

    @type dry_run: bool

    @keyword dry_run: whether to perform a dry run

    @rtype: int

    @return: job id

    """

    query = []

    if kwargs.get("dry_run"):

      query.append(("dry-run", 1))

    if _INST_CREATE_REQV1 in self.GetFeatures():

      # All required fields for request data version 1

      body = {

        _REQ_DATA_VERSION_FIELD: 1,

        "mode": mode,

        "name": name,

        "disk_template": disk_template,

        "disks": disks,

        "nics": nics,

        }

      conflicts = set(kwargs.iterkeys()) & set(body.iterkeys())

      if conflicts:

        raise GanetiApiError("Required fields can not be specified as"

                             " keywords: %s" % ", ".join(conflicts))

      body.update((key, value) for key, value in kwargs.iteritems()

                  if key != "dry_run")

    else:

      # Old request format (version 0)

      # The following code must make sure that an exception is raised when an

      # unsupported setting is requested by the caller. Otherwise this can lead

      # to bugs difficult to find. The interface of this function must stay

      # exactly the same for version 0 and 1 (e.g. they aren't allowed to

      # require different data types).

      # Validate disks

      for idx, disk in enumerate(disks):

        unsupported = set(disk.keys()) - _INST_CREATE_V0_DISK_PARAMS

        if unsupported:

          raise GanetiApiError("Server supports request version 0 only, but"

                               " disk %s specifies the unsupported parameters"

                               " %s, allowed are %s" %

                               (idx, unsupported,

                                list(_INST_CREATE_V0_DISK_PARAMS)))

      assert (len(_INST_CREATE_V0_DISK_PARAMS) == 1 and

              "size" in _INST_CREATE_V0_DISK_PARAMS)

      disk_sizes = [disk["size"] for disk in disks]

      # Validate NICs

      if not nics:

        raise GanetiApiError("Server supports request version 0 only, but"

                             " no NIC specified")

      elif len(nics) > 1:

        raise GanetiApiError("Server supports request version 0 only, but"

                             " more than one NIC specified")

      assert len(nics) == 1

      unsupported = set(nics[0].keys()) - _INST_NIC_PARAMS

      if unsupported:

        raise GanetiApiError("Server supports request version 0 only, but"

                             " NIC 0 specifies the unsupported parameters %s,"

                             " allowed are %s" %

                             (unsupported, list(_INST_NIC_PARAMS)))

      # Validate other parameters

      unsupported = (set(kwargs.keys()) - _INST_CREATE_V0_PARAMS -

                     _INST_CREATE_V0_DPARAMS)

      if unsupported:

        allowed = _INST_CREATE_V0_PARAMS.union(_INST_CREATE_V0_DPARAMS)

        raise GanetiApiError("Server supports request version 0 only, but"

                             " the following unsupported parameters are"

                             " specified: %s, allowed are %s" %

                             (unsupported, list(allowed)))

      # All required fields for request data version 0

      body = {

        _REQ_DATA_VERSION_FIELD: 0,

        "name": name,

        "disk_template": disk_template,

        "disks": disk_sizes,

        }

      # NIC fields

      assert len(nics) == 1

      assert not (set(body.keys()) & set(nics[0].keys()))

      body.update(nics[0])

      # Copy supported fields

      assert not (set(body.keys()) & set(kwargs.keys()))

      body.update(dict((key, value) for key, value in kwargs.items()

                       if key in _INST_CREATE_V0_PARAMS))

      # Merge dictionaries

      for i in (value for key, value in kwargs.items()

                if key in _INST_CREATE_V0_DPARAMS):

        assert not (set(body.keys()) & set(i.keys()))

        body.update(i)

      assert not (set(kwargs.keys()) -

                  (_INST_CREATE_V0_PARAMS | _INST_CREATE_V0_DPARAMS))

      assert not (set(body.keys()) & _INST_CREATE_V0_DPARAMS)

    return self._SendRequest(HTTP_POST, "/%s/instances" % GANETI_RAPI_VERSION,

                             query, body)

  def DeleteInstance(self, instance, dry_run=False):

    """Deletes an instance.

    @type instance: str

    @param instance: the instance to delete

    @rtype: int

    @return: job id

    """

    query = []

    if dry_run:

      query.append(("dry-run", 1))

    return self._SendRequest(HTTP_DELETE,

                             ("/%s/instances/%s" %

                              (GANETI_RAPI_VERSION, instance)), query, None)

  def GetInstanceTags(self, instance):

    """Gets tags for an instance.

    @type instance: str

    @param instance: instance whose tags to return

    @rtype: list of str

    @return: tags for the instance

    """

    return self._SendRequest(HTTP_GET,

                             ("/%s/instances/%s/tags" %

                              (GANETI_RAPI_VERSION, instance)), None, None)

  def AddInstanceTags(self, instance, tags, dry_run=False):

    """Adds tags to an instance.

    @type instance: str

    @param instance: instance to add tags to

    @type tags: list of str

    @param tags: tags to add to the instance

    @type dry_run: bool

    @param dry_run: whether to perform a dry run

    @rtype: int

    @return: job id

    """

    query = [("tag", t) for t in tags]

    if dry_run:

      query.append(("dry-run", 1))

    return self._SendRequest(HTTP_PUT,

                             ("/%s/instances/%s/tags" %

                              (GANETI_RAPI_VERSION, instance)), query, None)

  def DeleteInstanceTags(self, instance, tags, dry_run=False):

    """Deletes tags from an instance.

    @type instance: str

    @param instance: instance to delete tags from

    @type tags: list of str

    @param tags: tags to delete

    @type dry_run: bool

    @param dry_run: whether to perform a dry run

    """

    query = [("tag", t) for t in tags]

    if dry_run:

      query.append(("dry-run", 1))

    return self._SendRequest(HTTP_DELETE,

                             ("/%s/instances/%s/tags" %

                              (GANETI_RAPI_VERSION, instance)), query, None)

  def RebootInstance(self, instance, reboot_type=None, ignore_secondaries=None,

                     dry_run=False):

    """Reboots an instance.

    @type instance: str

    @param instance: instance to rebot

    @type reboot_type: str

    @param reboot_type: one of: hard, soft, full

    @type ignore_secondaries: bool

    @param ignore_secondaries: if True, ignores errors for the secondary node

        while re-assembling disks (in hard-reboot mode only)

    @type dry_run: bool

    @param dry_run: whether to perform a dry run

    """

    query = []

    if reboot_type:

      query.append(("type", reboot_type))

    if ignore_secondaries is not None:

      query.append(("ignore_secondaries", ignore_secondaries))

    if dry_run:

      query.append(("dry-run", 1))

    return self._SendRequest(HTTP_POST,

                             ("/%s/instances/%s/reboot" %

                              (GANETI_RAPI_VERSION, instance)), query, None)

  def ShutdownInstance(self, instance, dry_run=False):

    """Shuts down an instance.

    @type instance: str

    @param instance: the instance to shut down

    @type dry_run: bool

    @param dry_run: whether to perform a dry run

    """

    query = []

    if dry_run:

      query.append(("dry-run", 1))

    return self._SendRequest(HTTP_PUT,

                             ("/%s/instances/%s/shutdown" %

                              (GANETI_RAPI_VERSION, instance)), query, None)

  def StartupInstance(self, instance, dry_run=False):

    """Starts up an instance.

    @type instance: str

    @param instance: the instance to start up

    @type dry_run: bool

    @param dry_run: whether to perform a dry run

    """

    query = []

    if dry_run:

      query.append(("dry-run", 1))

    return self._SendRequest(HTTP_PUT,

                             ("/%s/instances/%s/startup" %

                              (GANETI_RAPI_VERSION, instance)), query, None)

  def ReinstallInstance(self, instance, os, no_startup=False):

    """Reinstalls an instance.

    @type instance: str

    @param instance: the instance to reinstall

    @type os: str

    @param os: the os to reinstall

    @type no_startup: bool

    @param no_startup: whether to start the instance automatically

    """

    query = [("os", os)]

    if no_startup:

      query.append(("nostartup", 1))

    return self._SendRequest(HTTP_POST,

                             ("/%s/instances/%s/reinstall" %

                              (GANETI_RAPI_VERSION, instance)), query, None)

  def ReplaceInstanceDisks(self, instance, disks=None, mode=REPLACE_DISK_AUTO,

                           remote_node=None, iallocator=None, dry_run=False):

    """Replaces disks on an instance.

    @type instance: str

    @param instance: instance whose disks to replace

    @type disks: list of ints

    @param disks: Indexes of disks to replace

    @type mode: str

    @param mode: replacement mode to use (defaults to replace_auto)

    @type remote_node: str or None

    @param remote_node: new secondary node to use (for use with

        replace_new_secondary mode)

    @type iallocator: str or None

    @param iallocator: instance allocator plugin to use (for use with

                       replace_auto mode)

    @type dry_run: bool

    @param dry_run: whether to perform a dry run

    @rtype: int

    @return: job id

    """

    query = [

      ("mode", mode),

      ]

    if disks:

      query.append(("disks", ",".join(str(idx) for idx in disks)))

    if remote_node:

      query.append(("remote_node", remote_node))

    if iallocator:

      query.append(("iallocator", iallocator))

    if dry_run:

      query.append(("dry-run", 1))

    return self._SendRequest(HTTP_POST,

                             ("/%s/instances/%s/replace-disks" %

                              (GANETI_RAPI_VERSION, instance)), query, None)

  def GetJobs(self):

    """Gets all jobs for the cluster.

    @rtype: list of int

    @return: job ids for the cluster

    """

    return [int(j["id"])

            for j in self._SendRequest(HTTP_GET,

                                       "/%s/jobs" % GANETI_RAPI_VERSION,

                                       None, None)]

  def GetJobStatus(self, job_id):

    """Gets the status of a job.

    @type job_id: int

    @param job_id: job id whose status to query

    @rtype: dict

    @return: job status

    """

    return self._SendRequest(HTTP_GET,

                             "/%s/jobs/%s" % (GANETI_RAPI_VERSION, job_id),

                             None, None)

  def WaitForJobChange(self, job_id, fields, prev_job_info, prev_log_serial):

    """Waits for job changes.

    @type job_id: int

    @param job_id: Job ID for which to wait

    """

    body = {

      "fields": fields,

      "previous_job_info": prev_job_info,

      "previous_log_serial": prev_log_serial,

      }

    return self._SendRequest(HTTP_GET,

                             "/%s/jobs/%s/wait" % (GANETI_RAPI_VERSION, job_id),

                             None, body)

  def CancelJob(self, job_id, dry_run=False):

    """Cancels a job.

    @type job_id: int

    @param job_id: id of the job to delete

    @type dry_run: bool

    @param dry_run: whether to perform a dry run

    """

    query = []

    if dry_run:

      query.append(("dry-run", 1))