+#!/usr/bin/env python
+
+from kamaki.clients.compute import ComputeClient
+from kamaki.config import Config
+
+from occi.core_model import Mixin
+from occi.backend import ActionBackend, KindBackend, MixinBackend
+from occi.extensions.infrastructure import COMPUTE, START, STOP, SUSPEND, RESTART, RESOURCE_TEMPLATE, OS_TEMPLATE
+
+from occi.wsgi import Application
+
+from wsgiref.simple_server import make_server
+from wsgiref.validate import validator
+
+
+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):
+ '''
+ A Backend for compute instances.
+ '''
+
+ def create(self, entity, extras):
+
+ for mixin in entity.mixins:
+ print mixin.term
+ print mixin.attributes
+ if mixin.related[0].term == 'os_tpl':
+ image = mixin.related[0]
+ image_id = mixin.attributes['occi.core.id']
+ if mixin.related[0].term == 'resource_tpl':
+ flavor = mixin.related[0]
+ flavor_id = mixin.attributes['occi.core.id']
+
+
+ entity.attributes['occi.compute.state'] = 'active'
+ entity.actions = [STOP, SUSPEND, RESTART]
+
+ #TODO VM identifier
+
+ snf = ComputeClient(Config())
+ 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'])
+
+ def retrieve(self, entity, extras):
+ # triggering cyclades to retrieve up to date information
+
+ 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):
+ # call the management framework to delete this compute instance...
+ print('Removing representation of virtual machine with id: '
+ + entity.identifier)
+
+ def action(self, entity, action, extras):
+ if action not in entity.actions:
+ raise AttributeError("This action is currently no applicable.")
+ elif action == START:
+ entity.attributes['occi.compute.state'] = 'active'
+ entity.actions = [STOP, SUSPEND, RESTART]
+ # read attributes from action and do something with it :-)
+ print('Starting virtual machine with id' + entity.identifier)
+ elif action == STOP:
+ entity.attributes['occi.compute.state'] = 'inactive'
+ entity.actions = [START]
+ # read attributes from action and do something with it :-)
+ print('Stopping virtual machine with id' + entity.identifier)
+ elif action == RESTART:
+ entity.actions = [STOP, SUSPEND, RESTART]
+ entity.attributes['occi.compute.state'] = 'active'
+ # read attributes from action and do something with it :-)
+ print('Restarting virtual machine with id' + entity.identifier)
+ elif action == SUSPEND:
+ entity.attributes['occi.compute.state'] = 'suspended'
+ entity.actions = [START]
+ # read attributes from action and do something with it :-)
+ print('Suspending virtual machine with id' + entity.identifier)
+
+
+class MyAPP(Application):
+ '''
+ An OCCI WSGI application.
+ '''
+
+ def __call__(self, environ, response):
+ sec_obj = {'username': 'password'}
+
+
+ #Refresh registry entries with current Cyclades state
+ snf = ComputeClient(Config())
+
+ images = snf.list_images()
+ for image in images:
+ IMAGE_ATTRIBUTES = {'occi.core.id': str(image['id'])}
+ IMAGE = Mixin("http://schemas.ogf.org/occi/infrastructure#", str(image['name']), [OS_TEMPLATE], attributes = IMAGE_ATTRIBUTES)
+ self.register_backend(IMAGE, MixinBackend())
+
+ flavors = snf.list_flavors()
+ for flavor in flavors:
+ FLAVOR_ATTRIBUTES = {'occi.core.id': flavor['id'],
+ 'occi.compute.cores': snf.get_flavor_details(flavor['id'])['cpu'],
+ 'occi.compute.memory': snf.get_flavor_details(flavor['id'])['ram'],
+ 'occi.storage.size': snf.get_flavor_details(flavor['id'])['disk'],
+ }
+ FLAVOR = Mixin("http://schemas.ogf.org/occi/infrastructure#", str(flavor['name']), [RESOURCE_TEMPLATE], attributes = FLAVOR_ATTRIBUTES)
+ self.register_backend(FLAVOR, MixinBackend())
+
+ #TODO show only current VM instances
+
+
+ return self._call_occi(environ, response, security=sec_obj, foo=None)
+
+if __name__ == '__main__':
+
+ APP = MyAPP()
+
+ COMPUTE_BACKEND = ComputeBackend()
+
+ APP.register_backend(COMPUTE, COMPUTE_BACKEND)
+ APP.register_backend(START, COMPUTE_BACKEND)
+ APP.register_backend(STOP, COMPUTE_BACKEND)
+ APP.register_backend(RESTART, COMPUTE_BACKEND)
+ APP.register_backend(SUSPEND, COMPUTE_BACKEND)
+ APP.register_backend(RESOURCE_TEMPLATE, MixinBackend())
+ APP.register_backend(OS_TEMPLATE, MixinBackend())
+
+
+ VALIDATOR_APP = validator(APP)
+ HTTPD = make_server('', 8888, VALIDATOR_APP)
+ HTTPD.serve_forever()
+