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OpenStack Study: server_groups.py**** CubicPower OpenStack Study ****
# Copyright (c) 2014 Cisco Systems, 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. """The Server Group API Extension.""" import webob from webob import exc from nova.api.openstack import common from nova.api.openstack import extensions from nova.api.openstack import wsgi from nova.api.openstack import xmlutil import nova.exception from nova.objects import instance as instance_obj from nova.objects import instance_group as instance_group_obj from nova.openstack.common.gettextutils import _ from nova import utils # NOTE(russellb) There is one other policy, 'legacy', but we don't allow that # being set via the API. It's only used when a group gets automatically # created to support the legacy behavior of the 'group' scheduler hint. SUPPORTED_POLICIES = ['anti-affinity', 'affinity'] authorize = extensions.extension_authorizer('compute', 'server_groups')
**** CubicPower OpenStack Study **** def make_policy(elem): elem.text = str
**** CubicPower OpenStack Study **** def make_member(elem): elem.text = str
**** CubicPower OpenStack Study **** def make_group(elem): elem.set('name') elem.set('id') policies = xmlutil.SubTemplateElement(elem, 'policies') policy = xmlutil.SubTemplateElement(policies, 'policy', selector='policies') make_policy(policy) members = xmlutil.SubTemplateElement(elem, 'members') member = xmlutil.SubTemplateElement(members, 'member', selector='members') make_member(member) elem.append(common.MetadataTemplate()) server_group_nsmap = {None: xmlutil.XMLNS_V11, 'atom': xmlutil.XMLNS_ATOM}
**** CubicPower OpenStack Study **** def _authorize_context(req): context = req.environ['nova.context'] authorize(context) return context
**** CubicPower OpenStack Study **** class ServerGroupTemplate(xmlutil.TemplateBuilder):
**** CubicPower OpenStack Study **** def construct(self): root = xmlutil.TemplateElement('server_group', selector='server_group') make_group(root) return xmlutil.MasterTemplate(root, 1, nsmap=server_group_nsmap)
**** CubicPower OpenStack Study **** class ServerGroupsTemplate(xmlutil.TemplateBuilder):
**** CubicPower OpenStack Study **** def construct(self): root = xmlutil.TemplateElement('server_groups') elem = xmlutil.SubTemplateElement(root, 'server_group', selector='server_groups') # Note: listing server groups only shows name and uuid make_group(elem) return xmlutil.MasterTemplate(root, 1, nsmap=server_group_nsmap)
**** CubicPower OpenStack Study **** class ServerGroupXMLDeserializer(wsgi.MetadataXMLDeserializer): """Deserializer to handle xml-formatted server group requests.""" metadata_deserializer = common.MetadataXMLDeserializer()
**** CubicPower OpenStack Study **** def default(self, string): """Deserialize an xml-formatted server group create request.""" dom = xmlutil.safe_minidom_parse_string(string) server_group = self._extract_server_group(dom) return {'body': {'server_group': server_group}}
**** CubicPower OpenStack Study **** def _extract_server_group(self, node): """Marshal the instance attribute of a parsed request.""" server_group = {} sg_node = self.find_first_child_named(node, 'server_group') if sg_node is not None: if sg_node.hasAttribute('name'): server_group['name'] = sg_node.getAttribute('name') if sg_node.hasAttribute('id'): server_group['id'] = sg_node.getAttribute('id') policies = self._extract_policies(sg_node) server_group['policies'] = policies or [] return server_group
**** CubicPower OpenStack Study **** def _extract_policies(self, server_group_node): """Marshal the server group policies element of a parsed request.""" policies_node = self.find_first_child_named(server_group_node, 'policies') if policies_node is not None: policy_nodes = self.find_children_named(policies_node, 'policy') policies = [] if policy_nodes is not None: for node in policy_nodes: policies.append(node.firstChild.nodeValue) return policies
**** CubicPower OpenStack Study **** def _extract_members(self, server_group_node): """Marshal the server group members element of a parsed request.""" members_node = self.find_first_child_named(server_group_node, 'members') if members_node is not None: member_nodes = self.find_children_named(members_node, 'member') members = [] if member_nodes is not None: for node in member_nodes: members.append(node.firstChild.nodeValue) return members
**** CubicPower OpenStack Study **** class ServerGroupController(wsgi.Controller): """The Server group API controller for the OpenStack API."""
**** CubicPower OpenStack Study **** def _format_server_group(self, context, group): # the id field has its value as the uuid of the server group # There is no 'uuid' key in server_group seen by clients. # In addition, clients see policies as a ["policy-name"] list; # and they see members as a ["server-id"] list. server_group = {} server_group['id'] = group.uuid server_group['name'] = group.name server_group['policies'] = group.policies or [] server_group['metadata'] = group.metadetails or {} members = [] if group.members: # Display the instances that are not deleted. filters = {'uuid': group.members, 'deleted_at': None} instances = instance_obj.InstanceList.get_by_filters( context, filters=filters) members = [instance.uuid for instance in instances] server_group['members'] = members return server_group
**** CubicPower OpenStack Study **** def _validate_policies(self, policies): """Validate the policies. Validates that there are no contradicting policies, for example 'anti-affinity' and 'affinity' in the same group. Validates that the defined policies are supported. :param policies: the given policies of the server_group """ if ('anti-affinity' in policies and 'affinity' in policies): msg = _("Conflicting policies configured!") raise nova.exception.InvalidInput(reason=msg) not_supported = [policy for policy in policies if policy not in SUPPORTED_POLICIES] if not_supported: msg = _("Invalid policies: %s") % ', '.join(not_supported) raise nova.exception.InvalidInput(reason=msg)
**** CubicPower OpenStack Study **** def _validate_input_body(self, body, entity_name): if not self.is_valid_body(body, entity_name): msg = _("the body is invalid.") raise nova.exception.InvalidInput(reason=msg) subbody = dict(body[entity_name]) expected_fields = ['name', 'policies'] for field in expected_fields: value = subbody.pop(field, None) if not value: msg = _("'%s' is either missing or empty.") % field raise nova.exception.InvalidInput(reason=msg) if field == 'name': utils.check_string_length(value, field, min_length=1, max_length=255) if not common.VALID_NAME_REGEX.search(value): msg = _("Invalid format for name: '%s'") % value raise nova.exception.InvalidInput(reason=msg) elif field == 'policies': if isinstance(value, list): [utils.check_string_length(v, field, min_length=1, max_length=255) for v in value] self._validate_policies(value) else: msg = _("'%s' is not a list") % value raise nova.exception.InvalidInput(reason=msg) if subbody: msg = _("unsupported fields: %s") % subbody.keys() raise nova.exception.InvalidInput(reason=msg) @wsgi.serializers(xml=ServerGroupTemplate)
**** CubicPower OpenStack Study **** def show(self, req, id): """Return data about the given server group.""" context = _authorize_context(req) try: sg = instance_group_obj.InstanceGroup.get_by_uuid(context, id) except nova.exception.InstanceGroupNotFound as e: raise webob.exc.HTTPNotFound(explanation=e.format_message()) return {'server_group': self._format_server_group(context, sg)}
**** CubicPower OpenStack Study **** def delete(self, req, id): """Delete an server group.""" context = _authorize_context(req) try: sg = instance_group_obj.InstanceGroup.get_by_uuid(context, id) sg.destroy(context) except nova.exception.InstanceGroupNotFound as e: raise webob.exc.HTTPNotFound(explanation=e.format_message()) return webob.Response(status_int=204) @wsgi.serializers(xml=ServerGroupsTemplate)
**** CubicPower OpenStack Study **** def index(self, req): """Returns a list of server groups.""" context = _authorize_context(req) project_id = context.project_id if 'all_projects' in req.GET and context.is_admin: sgs = instance_group_obj.InstanceGroupList.get_all(context) else: sgs = instance_group_obj.InstanceGroupList.get_by_project_id( context, project_id) limited_list = common.limited(sgs.objects, req) result = [self._format_server_group(context, group) for group in limited_list] return {'server_groups': result} @wsgi.serializers(xml=ServerGroupTemplate) @wsgi.deserializers(xml=ServerGroupXMLDeserializer)
**** CubicPower OpenStack Study **** def create(self, req, body): """Creates a new server group.""" context = _authorize_context(req) try: self._validate_input_body(body, 'server_group') except nova.exception.InvalidInput as e: raise exc.HTTPBadRequest(explanation=e.format_message()) vals = body['server_group'] sg = instance_group_obj.InstanceGroup() sg.project_id = context.project_id sg.user_id = context.user_id try: sg.name = vals.get('name') sg.policies = vals.get('policies') sg.create(context) except ValueError as e: raise exc.HTTPBadRequest(explanation=e) return {'server_group': self._format_server_group(context, sg)}
**** CubicPower OpenStack Study **** class ServerGroupsTemplateElement(xmlutil.TemplateElement):
**** CubicPower OpenStack Study **** def will_render(self, datum): return "server_groups" in datum
**** CubicPower OpenStack Study **** class Server_groups(extensions.ExtensionDescriptor): """Server group support.""" name = "ServerGroups" alias = "os-server-groups" namespace = ("http://docs.openstack.org/compute/ext/" "servergroups/api/v2") updated = "2013-06-20T00:00:00+00:00"
**** CubicPower OpenStack Study **** def get_resources(self): resources = [] res = extensions.ResourceExtension( 'os-server-groups', controller=ServerGroupController(), member_actions={"action": "POST", }) resources.append(res) return resources
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