emuvim/dcemulator/node.py

   1 """
   2 Distributed Cloud Emulator (dcemulator)
   3 (c) 2015 by Manuel Peuster <manuel.peuster@upb.de>
   4 """
   5 from mininet.node import Docker
   6 import logging
   7
   8
   9 DCDPID_BASE = 1000  # start of switch dpid's used for data center switches
  10
  11
  12 class EmulatorCompute(Docker):
  13     """
  14     Emulator specific compute node class.
  15     Inherits from Dockernet's Docker host class.
  16     Represents a single container connected to a (logical)
  17     data center.
  18     We can add emulator specific helper functions to it.
  19     """
  20
  21     def __init__(
  22             self, name, dimage, **kwargs):
  23         logging.debug("Create EmulatorCompute instance: %s" % name)
  24
  25         # call original Docker.__init__
  26         Docker.__init__(self, name, dimage, **kwargs)
  27
  28     def getNetworkStatus(self):
  29         """
  30         Helper method to receive information about the virtual networks
  31         this compute instance is connected to.
  32         """
  33         return None
  34
  35     def getStatus(self):
  36         """
  37         Helper method to receive information about this compute instance.
  38         """
  39         return None
  40
  41
  42 class Datacenter(object):
  43     """
  44     Represents a logical data center to which compute resources
  45     (Docker containers) can be added at runtime.
  46
  47     Will also implement resource bookkeeping in later versions.
  48     """
  49
  50     def __init__(self, name):
  51         self.net = None  # DCNetwork to which we belong
  52         self.name = name
  53         self.switch = None  # first prototype assumes one "bigswitch" per DC
  54         self.containers = {}  # keep track of running containers
  55
  56     def _get_next_dc_dpid(self):
  57         global DCDPID_BASE
  58         DCDPID_BASE += 1
  59         return DCDPID_BASE
  60
  61     def create(self):
  62         """
  63         Each data center is represented by a single switch to which
  64         compute resources can be connected at run time.
  65
  66         TODO: This will be changed in the future to support multiple networks
  67         per data center
  68         """
  69         self.switch = self.net.mnet.addSwitch(
  70             "%s.s1" % self.name, dpid=hex(self._get_next_dc_dpid())[2:])
  71         logging.debug("created data center switch: %s" % str(self.switch))
  72
  73     def start(self):
  74         pass
  75
  76     def startCompute(self, name, image=None, network=None):
  77         """
  78         Create a new container as compute resource and connect it to this
  79         data center.
  80
  81         TODO: This interface will change to support multiple networks to which
  82         a single container can be connected.
  83         """
  84         assert name is not None
  85         # set default parameter
  86         if image is None:
  87             image = "ubuntu"
  88         if network is None:
  89             network = {}  # {"ip": "10.0.0.254/8"}
  90         # create the container and connect it to the given network
  91         d = self.net.addDocker("%s" % (name), dimage=image)
  92         self.net.addLink(d, self.switch, params1=network)
  93         self.containers[name] = d
  94         return name  # we might use UUIDs for naming later on
  95
  96     def stopCompute(self, name):
  97         """
  98         Stop and remove a container from this data center.
  99         """
 100         assert name in self.containers
 101         self.net.removeLink(
 102             link=None, node1=self.containers[name], node2=self.switch)
 103         self.net.removeDocker("%s" % (name))
 104         del self.containers[name]
 105         return True
 106
 107     def listCompute(self):
 108         """
 109         Return a list of all running containers assigned to this
 110         data center.
 111         """
 112         return self.containers.itervalues()