emuvim/example_topology.py

   1 """
   2 This is an example topology for the distributed cloud emulator (dcemulator).
   3 (c) 2015 by Manuel Peuster <manuel.peuster@upb.de>
   4
   5
   6 This is an example that shows how a user of the emulation tool can
   7 define network topologies with multiple emulated cloud data centers.
   8
   9 The definition is done with a Python API which looks very similar to the
  10 Mininet API (in fact it is a wrapper for it).
  11
  12 We only specify the topology *between* data centers not within a single
  13 data center (data center internal setups or placements are not of interest,
  14 we want to experiment with VNF chains deployed across multiple PoPs).
  15
  16 The original Mininet API has to be completely hidden and not be used by this
  17 script.
  18 """
  19 import logging
  20 from mininet.log import setLogLevel
  21 from dcemulator.net import DCNetwork
  22 from api.zerorpcapi import ZeroRpcApiEndpoint
  23 from api.zerorpcapi_DCNetwork import ZeroRpcApiEndpointDCNetwork
  24
  25 logging.basicConfig(level=logging.INFO)
  26
  27
  28 def create_topology1():
  29     """
  30     1. Create a data center network object (DCNetwork)
  31     """
  32     net = DCNetwork()
  33
  34     """
  35     1b. add a monitoring agent to the DCNetwork
  36     """
  37     mon_api = ZeroRpcApiEndpointDCNetwork("0.0.0.0", 5151)
  38     mon_api.connectDCNetwork(net)
  39     mon_api.start()
  40     """
  41     2. Add (logical) data centers to the topology
  42        (each data center is one "bigswitch" in our simplified
  43         first prototype)
  44     """
  45     dc1 = net.addDatacenter("datacenter1")
  46     dc2 = net.addDatacenter("datacenter2")
  47     dc3 = net.addDatacenter("long_data_center_name3")
  48     dc4 = net.addDatacenter(
  49         "datacenter4",
  50         metadata={"mydata": "we can also add arbitrary metadata to each DC"})
  51
  52     """
  53     3. You can add additional SDN switches for data center
  54        interconnections to the network.
  55     """
  56     s1 = net.addSwitch("s1")
  57
  58     """
  59     4. Add links between your data centers and additional switches
  60        to define you topology.
  61        These links can use Mininet's features to limit bw, add delay or jitter.
  62     """
  63     net.addLink(dc1, dc2)
  64     net.addLink("datacenter1", s1)
  65     net.addLink(s1, dc3)
  66     net.addLink(s1, "datacenter4")
  67
  68     """
  69     5. We want to access and control our data centers from the outside,
  70        e.g., we want to connect an orchestrator to start/stop compute
  71        resources aka. VNFs (represented by Docker containers in the emulated)
  72
  73        So we need to instantiate API endpoints (e.g. a zerorpc or REST
  74        interface). Depending on the endpoint implementations, we can connect
  75        one or more data centers to it, which can then be controlled through
  76        this API, e.g., start/stop/list compute instances.
  77     """
  78     # create a new instance of a endpoint implementation
  79     zapi1 = ZeroRpcApiEndpoint("0.0.0.0", 4242)
  80     # connect data centers to this endpoint
  81     zapi1.connectDatacenter(dc1)
  82     zapi1.connectDatacenter(dc2)
  83     zapi1.connectDatacenter(dc3)
  84     zapi1.connectDatacenter(dc4)
  85     # run API endpoint server (in another thread, don't block)
  86     zapi1.start()
  87
  88     """
  89     5.1. For our example, we create a second endpoint to illustrate that
  90          this is supported by our design. This feature allows us to have
  91          one API endpoint for each data center. This makes the emulation
  92          environment more realistic because you can easily create one
  93          OpenStack-like REST API endpoint for *each* data center.
  94          This will look like a real-world multi PoP/data center deployment
  95          from the perspective of an orchestrator.
  96     """
  97     zapi2 = ZeroRpcApiEndpoint("0.0.0.0", 4343)
  98     zapi2.connectDatacenter(dc3)
  99     zapi2.connectDatacenter(dc4)
 100     zapi2.start()
 101
 102     """
 103     6. Finally we are done and can start our network (the emulator).
 104        We can also enter the Mininet CLI to interactively interact
 105        with our compute resources (just like in default Mininet).
 106        But we can also implement fully automated experiments that
 107        can be executed again and again.
 108     """
 109     net.start()
 110     net.CLI()
 111     # when the user types exit in the CLI, we stop the emulator
 112     # we need to explicitly stop the monitoring api, so the Ryu controller is also terminated
 113     mon_api.stop()
 114     net.stop()
 115
 116
 117 def main():
 118     setLogLevel('info')  # set Mininet loglevel
 119     create_topology1()
 120
 121
 122 if __name__ == '__main__':
 123     main()