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OpenStack Study: agents.py**** CubicPower OpenStack Study ****
# # 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 webob.exc from nova.api.openstack import extensions from nova.api.openstack import wsgi from nova.api.openstack import xmlutil from nova import db from nova import exception from nova import utils authorize = extensions.extension_authorizer('compute', 'agents')
**** CubicPower OpenStack Study **** class AgentsIndexTemplate(xmlutil.TemplateBuilder):
**** CubicPower OpenStack Study **** def construct(self): root = xmlutil.TemplateElement('agents') elem = xmlutil.SubTemplateElement(root, 'agent', selector='agents') elem.set('hypervisor') elem.set('os') elem.set('architecture') elem.set('version') elem.set('md5hash') elem.set('agent_id') elem.set('url') return xmlutil.MasterTemplate(root, 1)
**** CubicPower OpenStack Study **** class AgentController(object): """The agent is talking about guest agent.The host can use this for things like accessing files on the disk, configuring networking, or running other applications/scripts in the guest while it is running. Typically this uses some hypervisor-specific transport to avoid being dependent on a working network configuration. Xen, VMware, and VirtualBox have guest agents,although the Xen driver is the only one with an implementation for managing them in openstack. KVM doesn't really have a concept of a guest agent (although one could be written). You can find the design of agent update in this link: http://wiki.openstack.org/AgentUpdate and find the code in nova.virt.xenapi.vmops.VMOps._boot_new_instance. In this design We need update agent in guest from host, so we need some interfaces to update the agent info in host. You can find more information about the design of the GuestAgent in the following link: http://wiki.openstack.org/GuestAgent http://wiki.openstack.org/GuestAgentXenStoreCommunication """ @wsgi.serializers(xml=AgentsIndexTemplate)
**** CubicPower OpenStack Study **** def index(self, req): """Return a list of all agent builds. Filter by hypervisor.""" context = req.environ['nova.context'] authorize(context) hypervisor = None agents = [] if 'hypervisor' in req.GET: hypervisor = req.GET['hypervisor'] for agent_build in db.agent_build_get_all(context, hypervisor): agents.append({'hypervisor': agent_build.hypervisor, 'os': agent_build.os, 'architecture': agent_build.architecture, 'version': agent_build.version, 'md5hash': agent_build.md5hash, 'agent_id': agent_build.id, 'url': agent_build.url}) return {'agents': agents}
**** CubicPower OpenStack Study **** def update(self, req, id, body): """Update an existing agent build.""" context = req.environ['nova.context'] authorize(context) try: para = body['para'] url = para['url'] md5hash = para['md5hash'] version = para['version'] except (TypeError, KeyError): raise webob.exc.HTTPUnprocessableEntity() try: utils.check_string_length(url, 'url', max_length=255) utils.check_string_length(md5hash, 'md5hash', max_length=255) utils.check_string_length(version, 'version', max_length=255) except exception.InvalidInput as exc: raise webob.exc.HTTPBadRequest(explanation=exc.format_message()) try: db.agent_build_update(context, id, {'version': version, 'url': url, 'md5hash': md5hash}) except exception.AgentBuildNotFound as ex: raise webob.exc.HTTPNotFound(explanation=ex.format_message()) return {"agent": {'agent_id': id, 'version': version, 'url': url, 'md5hash': md5hash}}
**** CubicPower OpenStack Study **** def delete(self, req, id): """Deletes an existing agent build.""" context = req.environ['nova.context'] authorize(context) try: db.agent_build_destroy(context, id) except exception.AgentBuildNotFound as ex: raise webob.exc.HTTPNotFound(explanation=ex.format_message())
**** CubicPower OpenStack Study **** def create(self, req, body): """Creates a new agent build.""" context = req.environ['nova.context'] authorize(context) try: agent = body['agent'] hypervisor = agent['hypervisor'] os = agent['os'] architecture = agent['architecture'] version = agent['version'] url = agent['url'] md5hash = agent['md5hash'] except (TypeError, KeyError): raise webob.exc.HTTPUnprocessableEntity() try: utils.check_string_length(hypervisor, 'hypervisor', max_length=255) utils.check_string_length(os, 'os', max_length=255) utils.check_string_length(architecture, 'architecture', max_length=255) utils.check_string_length(version, 'version', max_length=255) utils.check_string_length(url, 'url', max_length=255) utils.check_string_length(md5hash, 'md5hash', max_length=255) except exception.InvalidInput as exc: raise webob.exc.HTTPBadRequest(explanation=exc.format_message()) try: agent_build_ref = db.agent_build_create(context, {'hypervisor': hypervisor, 'os': os, 'architecture': architecture, 'version': version, 'url': url, 'md5hash': md5hash}) agent['agent_id'] = agent_build_ref.id except exception.AgentBuildExists as ex: raise webob.exc.HTTPServerError(explanation=ex.format_message()) return {'agent': agent}
**** CubicPower OpenStack Study **** class Agents(extensions.ExtensionDescriptor): """Agents support.""" name = "Agents" alias = "os-agents" namespace = "http://docs.openstack.org/compute/ext/agents/api/v2" updated = "2012-10-28T00:00:00-00:00"
**** CubicPower OpenStack Study **** def get_resources(self): resources = [] resource = extensions.ResourceExtension('os-agents', AgentController()) resources.append(resource) return resources
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