vmware-nsx/neutron/plugins/nicira/NvpApiClient.py
armando-migliaccio 243d0cebb4 Deal with 501 errors from NVP correctly
This is done by adding the error code to the exception
handlers dictionary as done for other error codes.

Fixes bug #1215583

Change-Id: Ic876c6bccaf94cae626dfc908c4a34dfbcead406
2013-08-22 13:12:15 -07:00

260 lines
9.2 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2012 Nicira, Inc.
# All Rights Reserved
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
#
# @author: Somik Behera, Nicira Networks, Inc.
import httplib # basic HTTP library for HTTPS connections
import logging
from neutron.plugins.nicira.api_client import (
client_eventlet, request_eventlet)
LOG = logging.getLogger("NVPApiHelper")
LOG.setLevel(logging.INFO)
def _find_nvp_version_in_headers(headers):
# be safe if headers is None - do not cause a failure
for (header_name, header_value) in (headers or ()):
try:
if header_name == 'server':
return NVPVersion(header_value.split('/')[1])
except IndexError:
LOG.warning(_("Unable to fetch NVP version from response "
"headers:%s"), headers)
class NVPVersion(object):
"""Abstracts NVP version by exposing major and minor."""
def __init__(self, nvp_version):
self.full_version = nvp_version.split('.')
self.major = int(self.full_version[0])
self.minor = int(self.full_version[1])
def __str__(self):
return '.'.join(self.full_version)
class NVPApiHelper(client_eventlet.NvpApiClientEventlet):
'''API helper class.
Helper class to do basic login, cookie management, and provide base
method to send HTTP requests.
Implements new eventlet-based framework derived from the management
console nvp_gevent_client module.
'''
def __init__(self, api_providers, user, password, request_timeout,
http_timeout, retries, redirects,
concurrent_connections=3, nvp_gen_timeout=-1):
'''Constructor.
:param api_providers: a list of tuples in the form:
(host, port, is_ssl=True). Passed on to NvpClientEventlet.
:param user: the login username.
:param password: the login password.
:param concurrent_connections: the number of concurrent connections.
:param request_timeout: all operations (including retries, redirects
from unresponsive controllers, etc) should finish within this
timeout.
:param http_timeout: how long to wait before aborting an
unresponsive controller (and allow for retries to another
controller in the cluster)
:param retries: the number of concurrent connections.
:param redirects: the number of concurrent connections.
'''
client_eventlet.NvpApiClientEventlet.__init__(
self, api_providers, user, password, concurrent_connections,
nvp_gen_timeout)
self._request_timeout = request_timeout
self._http_timeout = http_timeout
self._retries = retries
self._redirects = redirects
self._nvp_version = None
# NOTE(salvatore-orlando): This method is not used anymore. Login is now
# performed automatically inside the request eventlet if necessary.
def login(self, user=None, password=None):
'''Login to NVP controller.
Assumes same password is used for all controllers.
:param user: NVP controller user (usually admin). Provided for
backwards compatability. In the normal mode of operation
this should be None.
:param password: NVP controller password. Provided for backwards
compatability. In the normal mode of operation this should
be None.
:returns: Does not return a value.
'''
if user:
self._user = user
if password:
self._password = password
return client_eventlet.NvpApiClientEventlet._login(self)
def request(self, method, url, body="", content_type="application/json"):
'''Issues request to controller.'''
g = request_eventlet.NvpGenericRequestEventlet(
self, method, url, body, content_type, auto_login=True,
request_timeout=self._request_timeout,
http_timeout=self._http_timeout,
retries=self._retries, redirects=self._redirects)
g.start()
response = g.join()
LOG.debug(_('NVPApiHelper.request() returns "%s"'), response)
# response is a modified HTTPResponse object or None.
# response.read() will not work on response as the underlying library
# request_eventlet.NvpApiRequestEventlet has already called this
# method in order to extract the body and headers for processing.
# NvpApiRequestEventlet derived classes call .read() and
# .getheaders() on the HTTPResponse objects and store the results in
# the response object's .body and .headers data members for future
# access.
if response is None:
# Timeout.
LOG.error(_('Request timed out: %(method)s to %(url)s'),
{'method': method, 'url': url})
raise RequestTimeout()
status = response.status
if status == httplib.UNAUTHORIZED:
raise UnAuthorizedRequest()
# Fail-fast: Check for exception conditions and raise the
# appropriate exceptions for known error codes.
if status in self.error_codes:
LOG.error(_("Received error code: %s"), status)
LOG.error(_("Server Error Message: %s"), response.body)
self.error_codes[status](self, response)
# Continue processing for non-error condition.
if (status != httplib.OK and status != httplib.CREATED
and status != httplib.NO_CONTENT):
LOG.error(_("%(method)s to %(url)s, unexpected response code: "
"%(status)d (content = '%(body)s')"),
{'method': method, 'url': url,
'status': response.status, 'body': response.body})
return None
if not self._nvp_version:
self._nvp_version = _find_nvp_version_in_headers(response.headers)
return response.body
def get_nvp_version(self):
if not self._nvp_version:
# Determine the NVP version by querying the control
# cluster nodes. Currently, the version will be the
# one of the server that responds.
self.request('GET', '/ws.v1/control-cluster/node')
if not self._nvp_version:
LOG.error(_('Unable to determine NVP version. '
'Plugin might not work as expected.'))
return self._nvp_version
def fourZeroFour(self, response=None):
raise ResourceNotFound()
def fourZeroNine(self, response=None):
raise Conflict()
def fiveZeroThree(self, response=None):
raise ServiceUnavailable()
def fourZeroThree(self, response=None):
if 'read-only' in response.body:
raise ReadOnlyMode()
else:
raise Forbidden()
def zero(self, response=None):
raise NvpApiException()
# TODO(del): ensure error_codes are handled/raised appropriately
# in api_client.
error_codes = {404: fourZeroFour,
409: fourZeroNine,
503: fiveZeroThree,
403: fourZeroThree,
301: zero,
307: zero,
400: zero,
500: zero,
501: zero,
503: zero}
class NvpApiException(Exception):
"""Base NvpApiClient Exception.
To correctly use this class, inherit from it and define
a 'message' property. That message will get printf'd
with the keyword arguments provided to the constructor.
"""
message = _("An unknown exception occurred.")
def __init__(self, **kwargs):
try:
self._error_string = self.message % kwargs
except Exception:
# at least get the core message out if something happened
self._error_string = self.message
def __str__(self):
return self._error_string
class UnAuthorizedRequest(NvpApiException):
message = _("Server denied session's authentication credentials.")
class ResourceNotFound(NvpApiException):
message = _("An entity referenced in the request was not found.")
class Conflict(NvpApiException):
message = _("Request conflicts with configuration on a different "
"entity.")
class ServiceUnavailable(NvpApiException):
message = _("Request could not completed because the associated "
"resource could not be reached.")
class Forbidden(NvpApiException):
message = _("The request is forbidden from accessing the "
"referenced resource.")
class ReadOnlyMode(Forbidden):
message = _("Create/Update actions are forbidden when in read-only mode.")
class RequestTimeout(NvpApiException):
message = _("The request has timed out.")