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
  24 logging.basicConfig(level=logging.INFO)
  25
  26
  27 def create_topology1():
  28     """
  29     1. Create a data center network object (DCNetwork)
  30     """
  31     net = DCNetwork()
  32
  33     """
  34     2. Add (logical) data centers to the topology
  35        (each data center is one "bigswitch" in our simplified
  36         first prototype)
  37     """
  38     dc1 = net.addDatacenter("datacenter1")
  39     dc2 = net.addDatacenter("datacenter2")
  40     dc3 = net.addDatacenter("long_data_center_name3")
  41     dc4 = net.addDatacenter(
  42         "datacenter4",
  43         metadata={"mydata": "we can also add arbitrary metadata to each DC"})
  44
  45     """
  46     3. You can add additional SDN switches for data center
  47        interconnections to the network.
  48     """
  49     s1 = net.addSwitch("s1")
  50
  51     """
  52     4. Add links between your data centers and additional switches
  53        to define you topology.
  54        These links can use Mininet's features to limit bw, add delay or jitter.
  55     """
  56     net.addLink(dc1, dc2)
  57     net.addLink("datacenter1", s1)
  58     net.addLink(s1, dc3)
  59     net.addLink(s1, "datacenter4")
  60
  61     """
  62     5. We want to access and control our data centers from the outside,
  63        e.g., we want to connect an orchestrator to start/stop compute
  64        resources aka. VNFs (represented by Docker containers in the emulated)
  65
  66        So we need to instantiate API endpoints (e.g. a zerorpc or REST
  67        interface). Depending on the endpoint implementations, we can connect
  68        one or more data centers to it, which can then be controlled through
  69        this API, e.g., start/stop/list compute instances.
  70     """
  71     # create a new instance of a endpoint implementation
  72     zapi1 = ZeroRpcApiEndpoint("0.0.0.0", 4242)
  73     # connect data centers to this endpoint
  74     zapi1.connectDatacenter(dc1)
  75     zapi1.connectDatacenter(dc2)
  76     zapi1.connectDatacenter(dc3)
  77     zapi1.connectDatacenter(dc4)
  78     # run API endpoint server (in another thread, don't block)
  79     zapi1.start()
  80
  81     """
  82     5.1. For our example, we create a second endpoint to illustrate that
  83          this is supported by our design. This feature allows us to have
  84          one API endpoint for each data center. This makes the emulation
  85          environment more realistic because you can easily create one
  86          OpenStack-like REST API endpoint for *each* data center.
  87          This will look like a real-world multi PoP/data center deployment
  88          from the perspective of an orchestrator.
  89     """
  90     zapi2 = ZeroRpcApiEndpoint("0.0.0.0", 4343)
  91     zapi2.connectDatacenter(dc3)
  92     zapi2.connectDatacenter(dc4)
  93     zapi2.start()
  94
  95     """
  96     6. Finally we are done and can start our network (the emulator).
  97        We can also enter the Mininet CLI to interactively interact
  98        with our compute resources (just like in default Mininet).
  99        But we can also implement fully automated experiments that
 100        can be executed again and again.
 101     """
 102     net.start()
 103     net.CLI()
 104     # when the user types exit in the CLI, we stop the emulator
 105     net.stop()
 106
 107
 108 def main():
 109     setLogLevel('info')  # set Mininet loglevel
 110     create_topology1()
 111
 112
 113 if __name__ == '__main__':
 114     main()