Synnefo » snf-ganeti

#

#

# Copyright (C) 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.

"""Ganeti RAPI client.

@attention: To use the RAPI client, the application B{must} call

            C{pycurl.global_init} during initialization and

            C{pycurl.global_cleanup} before exiting the process. This is very

            important in multi-threaded programs. See curl_global_init(3) and

            curl_global_cleanup(3) for details. The decorator L{UsesRapiClient}

            can be used.

"""

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

# be standalone.

import logging

import simplejson

import socket

import urllib

import threading

import pycurl

import time

try:

  from cStringIO import StringIO

except ImportError:

  from StringIO import StringIO

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_EVAC_PRI = "primary-only"

NODE_EVAC_SEC = "secondary-only"

NODE_EVAC_ALL = "all"

NODE_ROLE_DRAINED = "drained"

NODE_ROLE_MASTER_CANDIATE = "master-candidate"

NODE_ROLE_MASTER = "master"

NODE_ROLE_OFFLINE = "offline"

NODE_ROLE_REGULAR = "regular"

JOB_STATUS_QUEUED = "queued"

JOB_STATUS_WAITING = "waiting"

JOB_STATUS_CANCELING = "canceling"

JOB_STATUS_RUNNING = "running"

JOB_STATUS_CANCELED = "canceled"

JOB_STATUS_SUCCESS = "success"

JOB_STATUS_ERROR = "error"

JOB_STATUS_PENDING = frozenset([

  JOB_STATUS_QUEUED,

  JOB_STATUS_WAITING,

  JOB_STATUS_CANCELING,

  ])

JOB_STATUS_FINALIZED = frozenset([

  JOB_STATUS_CANCELED,

  JOB_STATUS_SUCCESS,

  JOB_STATUS_ERROR,

  ])

JOB_STATUS_ALL = frozenset([

  JOB_STATUS_RUNNING,

  ]) | JOB_STATUS_PENDING | JOB_STATUS_FINALIZED

# Legacy name

JOB_STATUS_WAITLOCK = JOB_STATUS_WAITING

# Internal constants

_REQ_DATA_VERSION_FIELD = "__version__"

_QPARAM_DRY_RUN = "dry-run"

_QPARAM_FORCE = "force"

# Feature strings

INST_CREATE_REQV1 = "instance-create-reqv1"

INST_REINSTALL_REQV1 = "instance-reinstall-reqv1"

NODE_MIGRATE_REQV1 = "node-migrate-reqv1"

NODE_EVAC_RES1 = "node-evac-res1"

# Old feature constant names in case they're references by users of this module

_INST_CREATE_REQV1 = INST_CREATE_REQV1

_INST_REINSTALL_REQV1 = INST_REINSTALL_REQV1

_NODE_MIGRATE_REQV1 = NODE_MIGRATE_REQV1

_NODE_EVAC_RES1 = NODE_EVAC_RES1

#: Resolver errors

ECODE_RESOLVER = "resolver_error"

#: Not enough resources (iallocator failure, disk space, memory, etc.)

ECODE_NORES = "insufficient_resources"

#: Temporarily out of resources; operation can be tried again

ECODE_TEMP_NORES = "temp_insufficient_resources"

#: Wrong arguments (at syntax level)

ECODE_INVAL = "wrong_input"

#: Wrong entity state

ECODE_STATE = "wrong_state"

#: Entity not found

ECODE_NOENT = "unknown_entity"

#: Entity already exists

ECODE_EXISTS = "already_exists"

#: Resource not unique (e.g. MAC or IP duplication)

ECODE_NOTUNIQUE = "resource_not_unique"

#: Internal cluster error

ECODE_FAULT = "internal_error"

#: Environment error (e.g. node disk error)

ECODE_ENVIRON = "environment_error"

#: List of all failure types

ECODE_ALL = frozenset([

  ECODE_RESOLVER,

  ECODE_NORES,

  ECODE_TEMP_NORES,

  ECODE_INVAL,

  ECODE_STATE,

  ECODE_NOENT,

  ECODE_EXISTS,

  ECODE_NOTUNIQUE,

  ECODE_FAULT,

  ECODE_ENVIRON,

  ])

# Older pycURL versions don't have all error constants

try:

  _CURLE_SSL_CACERT = pycurl.E_SSL_CACERT

  _CURLE_SSL_CACERT_BADFILE = pycurl.E_SSL_CACERT_BADFILE

except AttributeError:

  _CURLE_SSL_CACERT = 60

  _CURLE_SSL_CACERT_BADFILE = 77

_CURL_SSL_CERT_ERRORS = frozenset([

  _CURLE_SSL_CACERT,

  _CURLE_SSL_CACERT_BADFILE,

  ])

class Error(Exception):

  """Base error class for this module.

  """

  pass

class GanetiApiError(Error):

  """Generic error raised from Ganeti API.

  """

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

    Error.__init__(self, msg)

    self.code = code

class CertificateError(GanetiApiError):

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

  """

  pass

def _AppendIf(container, condition, value):

  """Appends to a list if a condition evaluates to truth.

  """

  if condition:

    container.append(value)

  return condition

def _AppendDryRunIf(container, condition):

  """Appends a "dry-run" parameter if a condition evaluates to truth.

  """

  return _AppendIf(container, condition, (_QPARAM_DRY_RUN, 1))

def _AppendForceIf(container, condition):

  """Appends a "force" parameter if a condition evaluates to truth.

  """

  return _AppendIf(container, condition, (_QPARAM_FORCE, 1))

def _SetItemIf(container, condition, item, value):

  """Sets an item if a condition evaluates to truth.

  """

  if condition:

    container[item] = value

  return condition

def UsesRapiClient(fn):

  """Decorator for code using RAPI client to initialize pycURL.

  """

  def wrapper(*args, **kwargs):

    # curl_global_init(3) and curl_global_cleanup(3) must be called with only

    # one thread running. This check is just a safety measure -- it doesn't

    # cover all cases.

    assert threading.activeCount() == 1, \

           "Found active threads when initializing pycURL"

    pycurl.global_init(pycurl.GLOBAL_ALL)

    try:

      return fn(*args, **kwargs)

    finally:

      pycurl.global_cleanup()

  return wrapper

def GenericCurlConfig(verbose=False, use_signal=False,

                      use_curl_cabundle=False, cafile=None, capath=None,

                      proxy=None, verify_hostname=False,

                      connect_timeout=None, timeout=None,

                      _pycurl_version_fn=pycurl.version_info):

  """Curl configuration function generator.

  @type verbose: bool

  @param verbose: Whether to set cURL to verbose mode

  @type use_signal: bool

  @param use_signal: Whether to allow cURL to use signals

  @type use_curl_cabundle: bool

  @param use_curl_cabundle: Whether to use cURL's default CA bundle

  @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 proxy: string

  @param proxy: Proxy to use, None for default behaviour and empty string for

                disabling proxies (see curl_easy_setopt(3))

  @type verify_hostname: bool

  @param verify_hostname: Whether to verify the remote peer certificate's

                          commonName

  @type connect_timeout: number

  @param connect_timeout: Timeout for establishing connection in seconds

  @type timeout: number

  @param timeout: Timeout for complete transfer in seconds (see

                  curl_easy_setopt(3)).

  """

  if use_curl_cabundle and (cafile or capath):

    raise Error("Can not use default CA bundle when CA file or path is set")

  def _ConfigCurl(curl, logger):

    """Configures a cURL object

    @type curl: pycurl.Curl

    @param curl: cURL object

    """

    logger.debug("Using cURL version %s", pycurl.version)

    # pycurl.version_info returns a tuple with information about the used

    # version of libcurl. Item 5 is the SSL library linked to it.

    # e.g.: (3, '7.18.0', 463360, 'x86_64-pc-linux-gnu', 1581, 'GnuTLS/2.0.4',

    # 0, '1.2.3.3', ...)

    sslver = _pycurl_version_fn()[5]

    if not sslver:

      raise Error("No SSL support in cURL")

    lcsslver = sslver.lower()

    if lcsslver.startswith("openssl/"):

      pass

    elif lcsslver.startswith("nss/"):

      # TODO: investigate compatibility beyond a simple test

      pass

    elif lcsslver.startswith("gnutls/"):

      if capath:

        raise Error("cURL linked against GnuTLS has no support for a"

                    " CA path (%s)" % (pycurl.version, ))

    else:

      raise NotImplementedError("cURL uses unsupported SSL version '%s'" %

                                sslver)

    curl.setopt(pycurl.VERBOSE, verbose)

    curl.setopt(pycurl.NOSIGNAL, not use_signal)

    # Whether to verify remote peer's CN

    if verify_hostname:

      # curl_easy_setopt(3): "When CURLOPT_SSL_VERIFYHOST is 2, that

      # certificate must indicate that the server is the server to which you

      # meant to connect, or the connection fails. [...] When the value is 1,

      # the certificate must contain a Common Name field, but it doesn't matter

      # what name it says. [...]"

      curl.setopt(pycurl.SSL_VERIFYHOST, 2)

    else:

      curl.setopt(pycurl.SSL_VERIFYHOST, 0)

    if cafile or capath or use_curl_cabundle:

      # Require certificates to be checked

      curl.setopt(pycurl.SSL_VERIFYPEER, True)

      if cafile:

        curl.setopt(pycurl.CAINFO, str(cafile))

      if capath:

        curl.setopt(pycurl.CAPATH, str(capath))

      # Not changing anything for using default CA bundle

    else:

      # Disable SSL certificate verification

      curl.setopt(pycurl.SSL_VERIFYPEER, False)

    if proxy is not None:

      curl.setopt(pycurl.PROXY, str(proxy))

    # Timeouts

    if connect_timeout is not None:

      curl.setopt(pycurl.CONNECTTIMEOUT, connect_timeout)

    if timeout is not None:

      curl.setopt(pycurl.TIMEOUT, timeout)

  return _ConfigCurl

class GanetiRapiClient(object): # pylint: disable=R0904

  """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, logger=logging,

               curl_config_fn=None, curl_factory=None):

    """Initializes this class.

    @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 curl_config_fn: callable

    @param curl_config_fn: Function to configure C{pycurl.Curl} object

    @param logger: Logging object

    """

    self._username = username

    self._password = password

    self._logger = logger

    self._curl_config_fn = curl_config_fn

    self._curl_factory = curl_factory

    try:

      socket.inet_pton(socket.AF_INET6, host)

      address = "[%s]:%s" % (host, port)

    except socket.error:

      address = "%s:%s" % (host, port)

    self._base_url = "https://%s" % address

    if username is not None:

      if password is None:

        raise Error("Password not specified")

    elif password:

      raise Error("Specified password without username")

  def _CreateCurl(self):

    """Creates a cURL object.

    """

    # Create pycURL object if no factory is provided

    if self._curl_factory:

      curl = self._curl_factory()

    else:

      curl = pycurl.Curl()

    # Default cURL settings

    curl.setopt(pycurl.VERBOSE, False)

    curl.setopt(pycurl.FOLLOWLOCATION, False)

    curl.setopt(pycurl.MAXREDIRS, 5)

    curl.setopt(pycurl.NOSIGNAL, True)

    curl.setopt(pycurl.USERAGENT, self.USER_AGENT)

    curl.setopt(pycurl.SSL_VERIFYHOST, 0)

    curl.setopt(pycurl.SSL_VERIFYPEER, False)

    curl.setopt(pycurl.HTTPHEADER, [

      "Accept: %s" % HTTP_APP_JSON,

      "Content-type: %s" % HTTP_APP_JSON,

      ])

    assert ((self._username is None and self._password is None) ^

            (self._username is not None and self._password is not None))

    if self._username:

      # Setup authentication

      curl.setopt(pycurl.HTTPAUTH, pycurl.HTTPAUTH_BASIC)

      curl.setopt(pycurl.USERPWD,

                  str("%s:%s" % (self._username, self._password)))

    # Call external configuration function

    if self._curl_config_fn:

      self._curl_config_fn(curl, self._logger)

    return curl

  @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("/")

    curl = self._CreateCurl()

    if content is not None:

      encoded_content = self._json_encoder.encode(content)

    else:

      encoded_content = ""

    # 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 (content=%r)",

                       method, url, encoded_content)

    # Buffer for response

    encoded_resp_body = StringIO()

    # Configure cURL

    curl.setopt(pycurl.CUSTOMREQUEST, str(method))

    curl.setopt(pycurl.URL, str(url))

    curl.setopt(pycurl.POSTFIELDS, str(encoded_content))

    curl.setopt(pycurl.WRITEFUNCTION, encoded_resp_body.write)

    try:

      # Send request and wait for response

      try:

        curl.perform()

      except pycurl.error, err:

        if err.args[0] in _CURL_SSL_CERT_ERRORS:

          raise CertificateError("SSL certificate error %s" % err,

                                 code=err.args[0])

        raise GanetiApiError(str(err), code=err.args[0])

    finally:

      # Reset settings to not keep references to large objects in memory

      # between requests

      curl.setopt(pycurl.POSTFIELDS, "")

      curl.setopt(pycurl.WRITEFUNCTION, lambda _: None)

    # Get HTTP response code

    http_code = curl.getinfo(pycurl.RESPONSE_CODE)

    # Was anything written to the response buffer?

    if encoded_resp_body.tell():

      response_content = simplejson.loads(encoded_resp_body.getvalue())

    else:

      response_content = None

    if http_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=http_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 RedistributeConfig(self):

    """Tells the cluster to redistribute its configuration files.

    @rtype: string

    @return: job id

    """

    return self._SendRequest(HTTP_PUT,

                             "/%s/redistribute-config" % GANETI_RAPI_VERSION,

                             None, None)

  def ModifyCluster(self, **kwargs):

    """Modifies cluster parameters.

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

    @rtype: string

    @return: job id

    """

    body = kwargs

    return self._SendRequest(HTTP_PUT,

                             "/%s/modify" % GANETI_RAPI_VERSION, None, body)

  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: string

    @return: job id

    """

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

    _AppendDryRunIf(query, dry_run)

    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

    @rtype: string

    @return: job id

    """

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

    _AppendDryRunIf(query, dry_run)

    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 = []

    _AppendIf(query, bulk, ("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)

  @staticmethod

  def _UpdateWithKwargs(base, **kwargs):

    """Updates the base with params from kwargs.

    @param base: The base dict, filled with required fields

    @note: This is an inplace update of base

    """

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

    if conflicts:

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

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

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

                if key != "dry_run")

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

                         **kwargs):

    """Generates an instance allocation as used by multiallocate.

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

    It is the same as used by CreateInstance.

    @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