+from kamaki.clients.compute import ComputeClient
+from kamaki.clients.cyclades import CycladesClient
+from kamaki.config import Config
+
+from occi.backend import ActionBackend, KindBackend
+from occi.extensions.infrastructure import COMPUTE, START, STOP, SUSPEND, RESTART
+
+
+#Compute Backend for snf-occi-server
+
+class MyBackend(KindBackend, ActionBackend):
+ '''
+ An very simple abstract backend which handles update and replace for
+ attributes. Support for links and mixins would need to added.
+ '''
+
+ def update(self, old, new, extras):
+ # here you can check what information from new_entity you wanna bring
+ # into old_entity
+
+ # trigger your hypervisor and push most recent information
+ print('Updating a resource with id: ' + old.identifier)
+ for item in new.attributes.keys():
+ old.attributes[item] = new.attributes[item]
+
+ def replace(self, old, new, extras):
+ print('Replacing a resource with id: ' + old.identifier)
+ old.attributes = {}
+ for item in new.attributes.keys():
+ old.attributes[item] = new.attributes[item]
+ old.attributes['occi.compute.state'] = 'inactive'
+
+
+class ComputeBackend(MyBackend):
+ '''
+ Backend for Cyclades/Openstack compute instances
+ '''
+
+ def create(self, entity, extras):
+
+ for mixin in entity.mixins:
+ if mixin.related[0].term == 'os_tpl':
+ image = mixin
+ image_id = mixin.attributes['occi.core.id']
+ if mixin.related[0].term == 'resource_tpl':
+ flavor = mixin
+ flavor_id = mixin.attributes['occi.core.id']
+
+ entity.attributes['occi.compute.state'] = 'active'
+ entity.actions = [STOP, SUSPEND, RESTART]
+
+ #Registry identifier is the uuid key occi.handler assigns
+ #attribute 'occi.core.id' will be the snf-server id
+
+ conf = Config()
+ conf.set('token',extras['token'])
+ snf = ComputeClient(conf)
+
+ vm_name = entity.attributes['occi.compute.hostname']
+ info = snf.create_server(vm_name, flavor_id, image_id)
+ entity.attributes['occi.core.id'] = str(info['id'])
+ entity.attributes['occi.compute.cores'] = flavor.attributes['occi.compute.cores']
+ entity.attributes['occi.compute.memory'] = flavor.attributes['occi.compute.memory']
+
+ def retrieve(self, entity, extras):
+
+ # triggering cyclades to retrieve up to date information
+ conf = Config()
+ conf.set('token',extras['token'])
+ snf = ComputeClient(conf)
+
+ vm_id = int(entity.attributes['occi.core.id'])
+ vm_info = snf.get_server_details(vm_id)
+ vm_state = vm_info['status']
+
+ status_dict = {'ACTIVE' : 'active',
+ 'STOPPED' : 'inactive',
+ 'ERROR' : 'inactive',
+ 'BUILD' : 'inactive',
+ 'DELETED' : 'inactive',
+ }
+
+ entity.attributes['occi.compute.state'] = status_dict[vm_state]
+
+ if entity.attributes['occi.compute.state'] == 'inactive':
+ entity.actions = [START]
+ if entity.attributes['occi.compute.state'] == 'active':
+ entity.actions = [STOP, SUSPEND, RESTART]
+ if entity.attributes['occi.compute.state'] == 'suspended':
+ entity.actions = [START]
+
+
+ def delete(self, entity, extras):
+
+ # delete vm with vm_id = entity.attributes['occi.core.id']
+ conf = Config()
+ conf.set('token',extras['token'])
+ snf = ComputeClient(conf)
+
+ vm_id = int(entity.attributes['occi.core.id'])
+ snf.delete_server(vm_id)
+
+
+ def action(self, entity, action, extras):
+
+ conf = Config()
+ conf.set('token',extras['token'])
+ client = CycladesClient(conf)
+
+ vm_id = int(entity.attributes['occi.core.id'])
+
+ if action not in entity.actions:
+ raise AttributeError("This action is currently no applicable.")
+
+ elif action == START:
+ print "Starting VM"
+ client.start_server(vm_id)
+
+
+ elif action == STOP:
+ print "Stopping VM"
+ client.shutdown_server(vm_id)
+
+ elif action == RESTART:
+ print "Restarting VM"
+ snf.reboot_server(vm_id)
+
+
+ elif action == SUSPEND:
+ #TODO VM suspending
+ print "Suspending VM"