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OpenStack Study: common.py**** CubicPower OpenStack Study ****
# Copyright 2010 OpenStack Foundation # 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 os import re from oslo.config import cfg import six.moves.urllib.parse as urlparse import webob from cinder.api.openstack import wsgi from cinder.api import xmlutil from cinder.openstack.common import log as logging from cinder import utils api_common_opts = [ cfg.IntOpt('osapi_max_limit', default=1000, help='the maximum number of items returned in a single ' 'response from a collection resource'), cfg.StrOpt('osapi_volume_base_URL', default=None, help='Base URL that will be presented to users in links ' 'to the OpenStack Volume API', deprecated_name='osapi_compute_link_prefix'), ] CONF = cfg.CONF CONF.register_opts(api_common_opts) LOG = logging.getLogger(__name__) XML_NS_V1 = 'http://docs.openstack.org/volume/api/v1' # Regex that matches alphanumeric characters, periods, hypens, # colons and underscores: # ^ assert position at start of the string # [\w\.\-\:\_] match expression # $ assert position at end of the string VALID_KEY_NAME_REGEX = re.compile(r"^[\w\.\-\:\_]+$", re.UNICODE)
**** CubicPower OpenStack Study **** def validate_key_names(key_names_list): """Validate each item of the list to match key name regex.""" for key_name in key_names_list: if not VALID_KEY_NAME_REGEX.match(key_name): return False return True
**** CubicPower OpenStack Study **** def get_pagination_params(request): """Return marker, limit tuple from request. :param request: `wsgi.Request` possibly containing 'marker' and 'limit' GET variables. 'marker' is the id of the last element the client has seen, and 'limit' is the maximum number of items to return. If 'limit' is not specified, 0, or > max_limit, we default to max_limit. Negative values for either marker or limit will cause exc.HTTPBadRequest() exceptions to be raised. """ params = {} if 'limit' in request.GET: params['limit'] = _get_limit_param(request) if 'marker' in request.GET: params['marker'] = _get_marker_param(request) return params
**** CubicPower OpenStack Study **** def _get_limit_param(request): """Extract integer limit from request or fail.""" try: limit = int(request.GET['limit']) except ValueError: msg = _('limit param must be an integer') raise webob.exc.HTTPBadRequest(explanation=msg) if limit < 0: msg = _('limit param must be positive') raise webob.exc.HTTPBadRequest(explanation=msg) return limit
**** CubicPower OpenStack Study **** def _get_marker_param(request): """Extract marker id from request or fail.""" return request.GET['marker']
**** CubicPower OpenStack Study **** def limited(items, request, max_limit=CONF.osapi_max_limit): """Return a slice of items according to requested offset and limit. :param items: A sliceable entity :param request: ``wsgi.Request`` possibly containing 'offset' and 'limit' GET variables. 'offset' is where to start in the list, and 'limit' is the maximum number of items to return. If 'limit' is not specified, 0, or > max_limit, we default to max_limit. Negative values for either offset or limit will cause exc.HTTPBadRequest() exceptions to be raised. :kwarg max_limit: The maximum number of items to return from 'items' """ try: offset = int(request.GET.get('offset', 0)) except ValueError: msg = _('offset param must be an integer') raise webob.exc.HTTPBadRequest(explanation=msg) try: limit = int(request.GET.get('limit', max_limit)) except ValueError: msg = _('limit param must be an integer') raise webob.exc.HTTPBadRequest(explanation=msg) if limit < 0: msg = _('limit param must be positive') raise webob.exc.HTTPBadRequest(explanation=msg) if offset < 0: msg = _('offset param must be positive') raise webob.exc.HTTPBadRequest(explanation=msg) limit = min(max_limit, limit or max_limit) range_end = offset + limit return items[offset:range_end]
**** CubicPower OpenStack Study **** def limited_by_marker(items, request, max_limit=CONF.osapi_max_limit): """Return a slice of items according to the requested marker and limit.""" params = get_pagination_params(request) limit = params.get('limit', max_limit) marker = params.get('marker') limit = min(max_limit, limit) start_index = 0 if marker: start_index = -1 for i, item in enumerate(items): if 'flavorid' in item: if item['flavorid'] == marker: start_index = i + 1 break elif item['id'] == marker or item.get('uuid') == marker: start_index = i + 1 break if start_index < 0: msg = _('marker [%s] not found') % marker raise webob.exc.HTTPBadRequest(explanation=msg) range_end = start_index + limit return items[start_index:range_end]
**** CubicPower OpenStack Study **** def remove_version_from_href(href): """Removes the first api version from the href. Given: 'http://www.cinder.com/v1.1/123' Returns: 'http://www.cinder.com/123' Given: 'http://www.cinder.com/v1.1' Returns: 'http://www.cinder.com' """ parsed_url = urlparse.urlsplit(href) url_parts = parsed_url.path.split('/', 2) # NOTE: this should match vX.X or vX expression = re.compile(r'^v([0-9]+|[0-9]+\.[0-9]+)(/.*|$)') if expression.match(url_parts[1]): del url_parts[1] new_path = '/'.join(url_parts) if new_path == parsed_url.path: msg = _('href %s does not contain version') % href LOG.debug(msg) raise ValueError(msg) parsed_url = list(parsed_url) parsed_url[2] = new_path return urlparse.urlunsplit(parsed_url)
**** CubicPower OpenStack Study **** def dict_to_query_str(params): # TODO(throughnothing): we should just use urllib.urlencode instead of this # But currently we don't work with urlencoded url's param_str = "" for key, val in params.iteritems(): param_str = param_str + '='.join([str(key), str(val)]) + '&' return param_str.rstrip('&')
**** CubicPower OpenStack Study **** class ViewBuilder(object): """Model API responses as dictionaries.""" _collection_name = None
**** CubicPower OpenStack Study **** def _get_links(self, request, identifier): return [{"rel": "self", "href": self._get_href_link(request, identifier), }, {"rel": "bookmark", "href": self._get_bookmark_link(request, identifier), }]
**** CubicPower OpenStack Study **** def _get_next_link(self, request, identifier): """Return href string with proper limit and marker params.""" params = request.params.copy() params["marker"] = identifier prefix = self._update_link_prefix(request.application_url, CONF.osapi_volume_base_URL) url = os.path.join(prefix, request.environ["cinder.context"].project_id, self._collection_name) return "%s?%s" % (url, dict_to_query_str(params))
**** CubicPower OpenStack Study **** def _get_href_link(self, request, identifier): """Return an href string pointing to this object.""" prefix = self._update_link_prefix(request.application_url, CONF.osapi_volume_base_URL) return os.path.join(prefix, request.environ["cinder.context"].project_id, self._collection_name, str(identifier))
**** CubicPower OpenStack Study **** def _get_bookmark_link(self, request, identifier): """Create a URL that refers to a specific resource.""" base_url = remove_version_from_href(request.application_url) base_url = self._update_link_prefix(base_url, CONF.osapi_volume_base_URL) return os.path.join(base_url, request.environ["cinder.context"].project_id, self._collection_name, str(identifier))
**** CubicPower OpenStack Study **** def _get_collection_links(self, request, items, id_key="uuid"): """Retrieve 'next' link, if applicable. This is included if: 1) 'limit' param is specified and equals the number of volumes. 2) 'limit' param is specified but it exceeds CONF.osapi_max_limit, in this case the number of volumes is CONF.osapi_max_limit. 3) 'limit' param is NOT specified but the number of volumes is CONF.osapi_max_limit. """ links = [] max_items = min( int(request.params.get("limit", CONF.osapi_max_limit)), CONF.osapi_max_limit) if max_items and max_items == len(items): last_item = items[-1] if id_key in last_item: last_item_id = last_item[id_key] else: last_item_id = last_item["id"] links.append({ "rel": "next", "href": self._get_next_link(request, last_item_id), }) return links
**** CubicPower OpenStack Study **** def _update_link_prefix(self, orig_url, prefix): if not prefix: return orig_url url_parts = list(urlparse.urlsplit(orig_url)) prefix_parts = list(urlparse.urlsplit(prefix)) url_parts[0:2] = prefix_parts[0:2] return urlparse.urlunsplit(url_parts)
**** CubicPower OpenStack Study **** class MetadataDeserializer(wsgi.MetadataXMLDeserializer):
**** CubicPower OpenStack Study **** def deserialize(self, text): dom = utils.safe_minidom_parse_string(text) metadata_node = self.find_first_child_named(dom, "metadata") metadata = self.extract_metadata(metadata_node) return {'body': {'metadata': metadata}}
**** CubicPower OpenStack Study **** class MetaItemDeserializer(wsgi.MetadataXMLDeserializer):
**** CubicPower OpenStack Study **** def deserialize(self, text): dom = utils.safe_minidom_parse_string(text) metadata_item = self.extract_metadata(dom) return {'body': {'meta': metadata_item}}
**** CubicPower OpenStack Study **** class MetadataXMLDeserializer(wsgi.XMLDeserializer):
**** CubicPower OpenStack Study **** def extract_metadata(self, metadata_node): """Marshal the metadata attribute of a parsed request.""" if metadata_node is None: return {} metadata = {} for meta_node in self.find_children_named(metadata_node, "meta"): key = meta_node.getAttribute("key") metadata[key] = self.extract_text(meta_node) return metadata
**** CubicPower OpenStack Study **** def _extract_metadata_container(self, datastring): dom = utils.safe_minidom_parse_string(datastring) metadata_node = self.find_first_child_named(dom, "metadata") metadata = self.extract_metadata(metadata_node) return {'body': {'metadata': metadata}}
**** CubicPower OpenStack Study **** def create(self, datastring): return self._extract_metadata_container(datastring)
**** CubicPower OpenStack Study **** def update_all(self, datastring): return self._extract_metadata_container(datastring)
**** CubicPower OpenStack Study **** def update(self, datastring): dom = utils.safe_minidom_parse_string(datastring) metadata_item = self.extract_metadata(dom) return {'body': {'meta': metadata_item}} metadata_nsmap = {None: xmlutil.XMLNS_V11}
**** CubicPower OpenStack Study **** class MetaItemTemplate(xmlutil.TemplateBuilder):
**** CubicPower OpenStack Study **** def construct(self): sel = xmlutil.Selector('meta', xmlutil.get_items, 0) root = xmlutil.TemplateElement('meta', selector=sel) root.set('key', 0) root.text = 1 return xmlutil.MasterTemplate(root, 1, nsmap=metadata_nsmap)
**** CubicPower OpenStack Study **** class MetadataTemplateElement(xmlutil.TemplateElement):
**** CubicPower OpenStack Study **** def will_render(self, datum): return True
**** CubicPower OpenStack Study **** class MetadataTemplate(xmlutil.TemplateBuilder):
**** CubicPower OpenStack Study **** def construct(self): root = MetadataTemplateElement('metadata', selector='metadata') elem = xmlutil.SubTemplateElement(root, 'meta', selector=xmlutil.get_items) elem.set('key', 0) elem.text = 1 return xmlutil.MasterTemplate(root, 1, nsmap=metadata_nsmap)
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