watcherclient.common.httpclient

Source code for watcherclient.common.httpclient

# Copyright 2012 OpenStack LLC.
# 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.

import copy
from distutils import version
import functools
import hashlib
import logging
import os
import socket
import ssl
import textwrap
import time

from keystoneauth1 import adapter
from keystoneauth1 import exceptions as kexceptions
from oslo_serialization import jsonutils
from oslo_utils import strutils
import requests
import six
from six.moves import http_client
import six.moves.urllib.parse as urlparse

from watcherclient._i18n import _
from watcherclient import exceptions


# NOTE(deva): Record the latest version that this client was tested with.
#             We still have a lot of work to do in the client to implement
#             microversion support in the client properly! See
#             http://specs.openstack.org/openstack/watcher-specs/specs/kilo/api-microversions.html # noqa
#             for full details.
DEFAULT_VER = '1.0'


LOG = logging.getLogger(__name__)
USER_AGENT = 'python-watcherclient'
CHUNKSIZE = 1024 * 64  # 64kB

API_VERSION = '/v1'
API_VERSION_SELECTED_STATES = ('user', 'negotiated', 'cached', 'default')


DEFAULT_MAX_RETRIES = 5
DEFAULT_RETRY_INTERVAL = 2
SENSITIVE_HEADERS = ('X-Auth-Token',)


SUPPORTED_ENDPOINT_SCHEME = ('http', 'https')


def _trim_endpoint_api_version(url):
    """Trim API version and trailing slash from endpoint."""
    return url.rstrip('/').rstrip(API_VERSION)


def _extract_error_json(body):
    """Return  error_message from the HTTP response body."""
    error_json = {}
    try:
        body_json = jsonutils.loads(body)
        if 'error_message' in body_json:
            raw_msg = body_json['error_message']
            error_json = jsonutils.loads(raw_msg)
    except ValueError:
        pass

    return error_json


[docs]def get_server(endpoint): """Extract and return the server & port that we're connecting to.""" if endpoint is None: return None, None parts = urlparse.urlparse(endpoint) return parts.hostname, str(parts.port)
[docs]class VersionNegotiationMixin(object):
[docs] def negotiate_version(self, conn, resp): """Negotiate the server version Assumption: Called after receiving a 406 error when doing a request. param conn: A connection object param resp: The response object from http request """ if self.api_version_select_state not in API_VERSION_SELECTED_STATES: raise RuntimeError( _('Error: self.api_version_select_state should be one of the ' 'values in: "%(valid)s" but had the value: "%(value)s"') % {'valid': ', '.join(API_VERSION_SELECTED_STATES), 'value': self.api_version_select_state}) min_ver, max_ver = self._parse_version_headers(resp) # NOTE: servers before commit 32fb6e99 did not return version headers # on error, so we need to perform a GET to determine # the supported version range if not max_ver: LOG.debug('No version header in response, requesting from server') if self.os_watcher_api_version: base_version = ("/v%s" % str(self.os_watcher_api_version).split('.')[0]) else: base_version = API_VERSION resp = self._make_simple_request(conn, 'GET', base_version) min_ver, max_ver = self._parse_version_headers(resp) # If the user requested an explicit version or we have negotiated a # version and still failing then error now. The server could # support the version requested but the requested operation may not # be supported by the requested version. if self.api_version_select_state == 'user': raise exceptions.UnsupportedVersion(textwrap.fill( _("Requested API version %(req)s is not supported by the " "server or the requested operation is not supported by the " "requested version. Supported version range is %(min)s to " "%(max)s") % {'req': self.os_watcher_api_version, 'min': min_ver, 'max': max_ver})) if self.api_version_select_state == 'negotiated': raise exceptions.UnsupportedVersion(textwrap.fill( _("No API version was specified and the requested operation " "was not supported by the client's negotiated API version " "%(req)s. Supported version range is: %(min)s to %(max)s") % {'req': self.os_watcher_api_version, 'min': min_ver, 'max': max_ver})) negotiated_ver = str( min(version.StrictVersion(self.os_watcher_api_version), version.StrictVersion(max_ver))) if negotiated_ver < min_ver: negotiated_ver = min_ver # server handles microversions, but doesn't support # the requested version, so try a negotiated version self.api_version_select_state = 'negotiated' self.os_watcher_api_version = negotiated_ver LOG.debug('Negotiated API version is %s', negotiated_ver) return negotiated_ver
def _generic_parse_version_headers(self, accessor_func): min_ver = accessor_func('X-OpenStack-Watcher-API-Minimum-Version', None) max_ver = accessor_func('X-OpenStack-Watcher-API-Maximum-Version', None) return min_ver, max_ver def _parse_version_headers(self, accessor_func): # NOTE(jlvillal): Declared for unit testing purposes raise NotImplementedError() def _make_simple_request(self, conn, method, url): # NOTE(jlvillal): Declared for unit testing purposes raise NotImplementedError()
_RETRY_EXCEPTIONS = (exceptions.ServiceUnavailable, exceptions.ConnectionRefused, kexceptions.RetriableConnectionFailure)
[docs]def with_retries(func): """Wrapper for _http_request adding support for retries.""" @functools.wraps(func) def wrapper(self, url, method, **kwargs): if self.conflict_max_retries is None: self.conflict_max_retries = DEFAULT_MAX_RETRIES if self.conflict_retry_interval is None: self.conflict_retry_interval = DEFAULT_RETRY_INTERVAL num_attempts = self.conflict_max_retries + 1 for attempt in range(1, num_attempts + 1): try: return func(self, url, method, **kwargs) except _RETRY_EXCEPTIONS as error: msg = ("Error contacting Watcher server: %(error)s. " "Attempt %(attempt)d of %(total)d" % {'attempt': attempt, 'total': num_attempts, 'error': error}) if attempt == num_attempts: LOG.error(msg) raise else: LOG.debug(msg) time.sleep(self.conflict_retry_interval) return wrapper
[docs]class HTTPClient(VersionNegotiationMixin): def __init__(self, endpoint, **kwargs): self.endpoint = endpoint self.endpoint_trimmed = _trim_endpoint_api_version(endpoint) self.auth_token = kwargs.get('token') self.auth_ref = kwargs.get('auth_ref') self.os_watcher_api_version = kwargs.get('os_watcher_api_version', DEFAULT_VER) self.api_version_select_state = kwargs.get( 'api_version_select_state', 'default') self.conflict_max_retries = kwargs.pop('max_retries', DEFAULT_MAX_RETRIES) self.conflict_retry_interval = kwargs.pop('retry_interval', DEFAULT_RETRY_INTERVAL) self.session = requests.Session() parts = urlparse.urlparse(endpoint) if parts.scheme not in SUPPORTED_ENDPOINT_SCHEME: msg = _('Unsupported scheme: %s') % parts.scheme raise exceptions.EndpointException(msg) if parts.scheme == 'https': if kwargs.get('insecure') is True: self.session.verify = False elif kwargs.get('ca_file'): self.session.verify = kwargs['ca_file'] self.session.cert = (kwargs.get('cert_file'), kwargs.get('key_file')) def _process_header(self, name, value): """Redacts any sensitive header Redact a header that contains sensitive information, by returning an updated header with the sha1 hash of that value. The redacted value is prefixed by '{SHA1}' because that's the convention used within OpenStack. :returns: A tuple of (name, value) name: the safe encoding format of name value: the redacted value if name is x-auth-token, or the safe encoding format of name """ if name in SENSITIVE_HEADERS: v = value.encode('utf-8') h = hashlib.sha1(v) d = h.hexdigest() return (name, "{SHA1}%s" % d) else: return (name, value)
[docs] def log_curl_request(self, method, url, kwargs): curl = ['curl -i -X %s' % method] for (key, value) in kwargs['headers'].items(): header = '-H \'%s: %s\'' % self._process_header(key, value) curl.append(header) if not self.session.verify: curl.append('-k') elif isinstance(self.session.verify, six.string_types): curl.append('--cacert %s' % self.session.verify) if self.session.cert: curl.append('--cert %s' % self.session.cert[0]) curl.append('--key %s' % self.session.cert[1]) if 'body' in kwargs: body = strutils.mask_password(kwargs['body']) curl.append('-d \'%s\'' % body) curl.append(urlparse.urljoin(self.endpoint_trimmed, url)) LOG.debug(' '.join(curl))
[docs] @staticmethod def log_http_response(resp, body=None): # NOTE(aarefiev): resp.raw is urllib3 response object, it's used # only to get 'version', response from request with 'stream = True' # should be used for raw reading. status = (resp.raw.version / 10.0, resp.status_code, resp.reason) dump = ['\nHTTP/%.1f %s %s' % status] dump.extend(['%s: %s' % (k, v) for k, v in resp.headers.items()]) dump.append('') if body: body = strutils.mask_password(body) dump.extend([body, '']) LOG.debug('\n'.join(dump))
def _make_connection_url(self, url): return urlparse.urljoin(self.endpoint_trimmed, url) def _parse_version_headers(self, resp): return self._generic_parse_version_headers(resp.headers.get) def _make_simple_request(self, conn, method, url): return conn.request(method, self._make_connection_url(url)) @with_retries def _http_request(self, url, method, **kwargs): """Send an http request with the specified characteristics. Wrapper around request.Session.request to handle tasks such as setting headers and error handling. """ # Copy the kwargs so we can reuse the original in case of redirects kwargs['headers'] = copy.deepcopy(kwargs.get('headers', {})) kwargs['headers'].setdefault('User-Agent', USER_AGENT) if self.os_watcher_api_version: kwargs['headers'].setdefault('X-OpenStack-Watcher-API-Version', self.os_watcher_api_version) if self.auth_token: kwargs['headers'].setdefault('X-Auth-Token', self.auth_token) self.log_curl_request(method, url, kwargs) # NOTE(aarefiev): This is for backwards compatibility, request # expected body in 'data' field, previously we used httplib, # which expected 'body' field. body = kwargs.pop('body', None) if body: kwargs['data'] = body conn_url = self._make_connection_url(url) try: resp = self.session.request(method, conn_url, **kwargs) # TODO(deva): implement graceful client downgrade when connecting # to servers that did not support microversions. Details here: # http://specs.openstack.org/openstack/watcher-specs/specs/kilo/api-microversions.html#use-case-3b-new-client-communicating-with-a-old-watcher-user-specified # noqa if resp.status_code == http_client.NOT_ACCEPTABLE: negotiated_ver = self.negotiate_version(self.session, resp) kwargs['headers']['X-OpenStack-Watcher-API-Version'] = ( negotiated_ver) return self._http_request(url, method, **kwargs) except requests.exceptions.RequestException as e: message = (_("Error has occurred while handling " "request for %(url)s: %(e)s") % dict(url=conn_url, e=e)) # NOTE(aarefiev): not valid request(invalid url, missing schema, # and so on), retrying is not needed. if isinstance(e, ValueError): raise exceptions.ValidationError(message) raise exceptions.ConnectionRefused(message) body_iter = resp.iter_content(chunk_size=CHUNKSIZE) # Read body into string if it isn't obviously image data body_str = None if resp.headers.get('Content-Type') != 'application/octet-stream': # decoding byte to string is necessary for Python 3 compatibility # this issues has not been found with Python 3 unit tests # because the test creates a fake http response of type str # the if statement satisfies test (str) and real (bytes) behavior body_list = [ chunk.decode("utf-8") if isinstance(chunk, bytes) else chunk for chunk in body_iter ] body_str = ''.join(body_list) self.log_http_response(resp, body_str) body_iter = six.StringIO(body_str) else: self.log_http_response(resp) if resp.status_code >= http_client.BAD_REQUEST: error_json = _extract_error_json(body_str) raise exceptions.from_response( resp, error_json.get('faultstring'), error_json.get('debuginfo'), method, url) elif resp.status_code in (http_client.MOVED_PERMANENTLY, http_client.FOUND, http_client.USE_PROXY): # Redirected. Reissue the request to the new location. return self._http_request(resp['location'], method, **kwargs) elif resp.status_code == http_client.MULTIPLE_CHOICES: raise exceptions.from_response(resp, method=method, url=url) return resp, body_iter
[docs] def json_request(self, method, url, **kwargs): kwargs.setdefault('headers', {}) kwargs['headers'].setdefault('Content-Type', 'application/json') kwargs['headers'].setdefault('Accept', 'application/json') if 'body' in kwargs: kwargs['body'] = jsonutils.dumps(kwargs['body']) resp, body_iter = self._http_request(url, method, **kwargs) content_type = resp.headers.get('Content-Type') if (resp.status_code in (http_client.NO_CONTENT, http_client.RESET_CONTENT) or content_type is None): return resp, list() if 'application/json' in content_type: body = ''.join([chunk for chunk in body_iter]) try: body = jsonutils.loads(body) except ValueError: LOG.error('Could not decode response body as JSON') else: body = None return resp, body
[docs] def raw_request(self, method, url, **kwargs): kwargs.setdefault('headers', {}) kwargs['headers'].setdefault('Content-Type', 'application/octet-stream') return self._http_request(url, method, **kwargs)
[docs]class VerifiedHTTPSConnection(six.moves.http_client.HTTPSConnection): """httplib-compatible connection using client-side SSL authentication :see http://code.activestate.com/recipes/ 577548-https-httplib-client-connection-with-certificate-v/ """ def __init__(self, host, port, key_file=None, cert_file=None, ca_file=None, timeout=None, insecure=False): six.moves.http_client.HTTPSConnection.__init__(self, host, port, key_file=key_file, cert_file=cert_file) self.key_file = key_file self.cert_file = cert_file if ca_file is not None: self.ca_file = ca_file else: self.ca_file = self.get_system_ca_file() self.timeout = timeout self.insecure = insecure
[docs] def connect(self): """Connect to a host on a given (SSL) port. If ca_file is pointing somewhere, use it to check Server Certificate. Redefined/copied and extended from httplib.py:1105 (Python 2.6.x). This is needed to pass cert_reqs=ssl.CERT_REQUIRED as parameter to ssl.wrap_socket(), which forces SSL to check server certificate against our client certificate. """ sock = socket.create_connection((self.host, self.port), self.timeout) if self._tunnel_host: self.sock = sock self._tunnel() if self.insecure is True: kwargs = {'cert_reqs': ssl.CERT_NONE} else: kwargs = {'cert_reqs': ssl.CERT_REQUIRED, 'ca_certs': self.ca_file} if self.cert_file: kwargs['certfile'] = self.cert_file if self.key_file: kwargs['keyfile'] = self.key_file self.sock = ssl.wrap_socket(sock, **kwargs)
[docs] @staticmethod def get_system_ca_file(): """Return path to system default CA file.""" # Standard CA file locations for Debian/Ubuntu, RedHat/Fedora, # Suse, FreeBSD/OpenBSD ca_path = ['/etc/ssl/certs/ca-certificates.crt', '/etc/pki/tls/certs/ca-bundle.crt', '/etc/ssl/ca-bundle.pem', '/etc/ssl/cert.pem'] for ca in ca_path: if os.path.exists(ca): return ca return None
[docs]class SessionClient(VersionNegotiationMixin, adapter.LegacyJsonAdapter): """HTTP client based on Keystone client session.""" def __init__(self, os_watcher_api_version, api_version_select_state, max_retries, retry_interval, endpoint, **kwargs): self.os_watcher_api_version = os_watcher_api_version self.api_version_select_state = api_version_select_state self.conflict_max_retries = max_retries self.conflict_retry_interval = retry_interval self.endpoint = endpoint super(SessionClient, self).__init__(**kwargs) def _parse_version_headers(self, resp): return self._generic_parse_version_headers(resp.headers.get) def _make_simple_request(self, conn, method, url): # NOTE: conn is self.session for this class return conn.request(url, method, raise_exc=False) @with_retries def _http_request(self, url, method, **kwargs): kwargs.setdefault('user_agent', USER_AGENT) kwargs.setdefault('auth', self.auth) if isinstance(self.endpoint_override, six.string_types): kwargs.setdefault( 'endpoint_override', _trim_endpoint_api_version(self.endpoint_override) ) if getattr(self, 'os_watcher_api_version', None): kwargs['headers'].setdefault('X-OpenStack-Watcher-API-Version', self.os_watcher_api_version) endpoint_filter = kwargs.setdefault('endpoint_filter', {}) endpoint_filter.setdefault('interface', self.interface) endpoint_filter.setdefault('service_type', self.service_type) endpoint_filter.setdefault('region_name', self.region_name) resp = self.session.request(url, method, raise_exc=False, **kwargs) if resp.status_code == http_client.NOT_ACCEPTABLE: negotiated_ver = self.negotiate_version(self.session, resp) kwargs['headers']['X-OpenStack-Watcher-API-Version'] = ( negotiated_ver) return self._http_request(url, method, **kwargs) if resp.status_code >= http_client.BAD_REQUEST: error_json = _extract_error_json(resp.content) raise exceptions.from_response( resp, error_json.get('faultstring'), error_json.get('debuginfo'), method, url) elif resp.status_code in (http_client.MOVED_PERMANENTLY, http_client.FOUND, http_client.USE_PROXY): # Redirected. Reissue the request to the new location. location = resp.headers.get('location') resp = self._http_request(location, method, **kwargs) elif resp.status_code == http_client.MULTIPLE_CHOICES: raise exceptions.from_response(resp, method=method, url=url) return resp
[docs] def json_request(self, method, url, **kwargs): kwargs.setdefault('headers', {}) kwargs['headers'].setdefault('Content-Type', 'application/json') kwargs['headers'].setdefault('Accept', 'application/json') if 'body' in kwargs: kwargs['data'] = jsonutils.dumps(kwargs.pop('body')) resp = self._http_request(url, method, **kwargs) body = resp.content content_type = resp.headers.get('content-type', None) status = resp.status_code if (status in (http_client.NO_CONTENT, http_client.RESET_CONTENT) or content_type is None): return resp, list() if 'application/json' in content_type: try: body = resp.json() except ValueError: LOG.error('Could not decode response body as JSON') else: body = None return resp, body
[docs] def raw_request(self, method, url, **kwargs): kwargs.setdefault('headers', {}) kwargs['headers'].setdefault('Content-Type', 'application/octet-stream') return self._http_request(url, method, **kwargs)
def _construct_http_client(endpoint=None, session=None, token=None, auth_ref=None, os_watcher_api_version=DEFAULT_VER, api_version_select_state='default', max_retries=DEFAULT_MAX_RETRIES, retry_interval=DEFAULT_RETRY_INTERVAL, timeout=600, ca_file=None, cert_file=None, key_file=None, insecure=None, **kwargs): if session: kwargs.setdefault('service_type', 'infra-optim') kwargs.setdefault('user_agent', 'python-watcherclient') kwargs.setdefault('interface', kwargs.pop('endpoint_type', None)) kwargs.setdefault('endpoint_override', endpoint) ignored = {'token': token, 'auth_ref': auth_ref, 'timeout': timeout != 600, 'ca_file': ca_file, 'cert_file': cert_file, 'key_file': key_file, 'insecure': insecure} dvars = [k for k, v in ignored.items() if v] if dvars: LOG.warning('The following arguments are ignored when using ' 'the session to construct a client: %s', ', '.join(dvars)) return SessionClient(session=session, os_watcher_api_version=os_watcher_api_version, api_version_select_state=api_version_select_state, max_retries=max_retries, retry_interval=retry_interval, endpoint=endpoint, **kwargs) else: if kwargs: LOG.warning('The following arguments are being ignored when ' 'constructing the client: %s', ', '.join(kwargs)) return HTTPClient(endpoint=endpoint, token=token, auth_ref=auth_ref, os_watcher_api_version=os_watcher_api_version, api_version_select_state=api_version_select_state, max_retries=max_retries, retry_interval=retry_interval, timeout=timeout, ca_file=ca_file, cert_file=cert_file, key_file=key_file, insecure=insecure)
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