def __init__(self, checker, port):
""" Initialize the RoboEarth Cloud Engine realm.
@param checker: Login checker which authenticates the User when
an initial request is received.
@type checker: twisted.cred.checkers.ICredentialsChecker
@param port: Port where the robot process is listening for
connections from other endpoints.
@type port: int
"""
self._checker = checker
self._port = port
self._network = Network()
self._balancer = LoadBalancer()
self._distributor = Distributor()
self._users = {}
self._pendingContainer = {}
class RoboEarthCloudEngine(object):
""" Realm for the twisted cred system. It is responsible for storing all
cloud engine relevant informations by having a reference to a Network,
Load Balancer, and Distributor instance, where each is responsible for
part of the system. Additionally, the realm keeps a list of all User
object.
There should be only one instance running in the Master process.
"""
implements(IRealm, IMasterRealm)
def __init__(self, checker, port):
""" Initialize the RoboEarth Cloud Engine realm.
@param checker: Login checker which authenticates the User when
an initial request is received.
@type checker: twisted.cred.checkers.ICredentialsChecker
@param port: Port where the robot process is listening for
connections from other endpoints.
@type port: int
"""
self._checker = checker
self._port = port
self._network = Network()
self._balancer = LoadBalancer()
self._distributor = Distributor()
self._users = {}
self._pendingContainer = {}
def requestAvatar(self, avatarId, mind, *interfaces):
""" Returns Avatar for slave processes of the cloud engine.
Implementation for IRealm
"""
if IPerspective not in interfaces:
raise NotImplementedError('RoboEarthCloudEngine only '
'handles IPerspective.')
# There are three possible roles (=avatarId):
# 'container', 'robot', and 'environment'
if avatarId == 'container':
machine = self._balancer.createMachine(mind[0], mind[1])
avatar = MachineAvatar(machine, self._balancer)
detach = lambda: avatar.logout()
print('Connection to Container process established.')
elif avatarId == 'robot':
endpoint = RobotEndpoint(self._network, self._distributor,
self._port)
endpoint.callback(mind)
avatar = RobotEndpointAvatar(self, endpoint)
detach = lambda: avatar.logout()
print('Connection to Robot process established.')
elif avatarId == 'environment':
endpoint = self._pendingContainer.pop(mind[1])
endpoint.callback(mind[0])
avatar = EnvironmentEndpointAvatar(self, endpoint)
detach = lambda: avatar.logout()
print('Connection to Environment process established.')
else:
raise InternalError('Invalid avatar ID received.')
return IPerspective, avatar, detach
def getUser(self, userID):
""" Get the user object matching the given user ID.
@param userID: user ID of the user which should be retrieved.
@type userID: str
@return: User object matching the user ID.
@rtype: rce.core.user.User
"""
if userID not in self._users:
self._users[userID] = User(self, userID)
return self._users[userID]
def requestURL(self, userID):
""" Callback for Robot resource to retrieve the location of the Robot
process to which a WebSocket connection should be established.
@param userID: User ID under which the robot will login.
(Can be used to do optimizations in distributing
the load.)
@type userID: str
@return: The IP address of Robot process to which a
WebSocket connection should be established.
(type: str)
@rtype: twisted.internet.defer.Deferred
"""
try:
location = self._distributor.getNextLocation()
except RobotProcessError:
# TODO: What should we do here?
raise InternalError('Robot can not be created.')
return location.getWebsocketAddress()
def createContainer(self, userID, data):
""" Callback for User instance to create a new Container object in a
container process.
@param userID: UserID of the user who created the container.
@type userID: str
@param data: Extra data which is used to configure the
container.
@param data: dict
@return: New Namespace and Container instance.
@rtype: (rce.core.environment.Environment,
rce.core.container.Container)
(subclasses of rce.core.base.Proxy)
"""
while 1:
uid = uuid4().hex
if uid not in self._pendingContainer:
break
try:
container = self._balancer.createContainer(uid, userID, data)
except ContainerProcessError:
# TODO: What should we do here?
raise InternalError('Container can not be created.')
endpoint = EnvironmentEndpoint(self._network, container)
self._pendingContainer[uid] = endpoint
return endpoint.createNamespace(), container
def checkUIDValidity(self, uid):
"""Method to check if incoming environment ID is valid.
@param uid: UID to be tested.
@type uid: str
"""
if uid not in self._pendingContainer:
raise CredentialError('Invalid environment ID.')
def createConnection(self, interfaceA, interfaceB):
""" Callback for User instance to create a new connection between two
interfaces.
@param interfaceX: Interface which should be connected.
@type interfaceX: rce.master.network.Interface
@return: New Connection instance.
@rtype: rce.core.network.Connection
"""
return self._network.createConnection(interfaceA, interfaceB)
def preShutdown(self):
""" Method is executed by the twisted reactor when a shutdown event
is triggered, before the reactor is being stopped.
"""
for user in self._users.values():
user.destroy()
def postShutdown(self):
""" Method is executed by the twisted reactor when a shutdown event
is triggered, after the reactor has been stopped.
"""
self._network.cleanUp()
self._balancer.cleanUp()
self._distributor.cleanUp()
