This is an example topology for the distributed cloud emulator (dcemulator).
(c) 2015 by Manuel Peuster <manuel.peuster@upb.de>
+
+This is an example that shows how a user of the emulation tool can
+define network topologies with multiple emulated cloud data centers.
+
+The definition is done with a Python API which looks very similar to the
+Mininet API (in fact it is a wrapper for it).
+
+We only specify the topology *between* data centers not within a single
+data center (data center internal setups or placements are not of interest,
+we want to experiment with VNF chains deployed across multiple PoPs).
+
The original Mininet API has to be completely hidden and not be used by this
script.
"""
import logging
+from mininet.log import setLogLevel
from dcemulator.net import DCNetwork
+from api.zerorpcapi import ZeroRpcApiEndpoint
-logging.basicConfig(level=logging.DEBUG)
+logging.basicConfig(level=logging.INFO)
def create_topology1():
- # initialize network
+ """
+ 1. Create a data center network object (DCNetwork)
+ """
net = DCNetwork()
- # add data centers
- dc1 = net.addDatacenter("dc1")
- dc2 = net.addDatacenter("dc2")
- dc3 = net.addDatacenter("dc3")
- dc4 = net.addDatacenter("dc4")
- # add additional SDN switches to our topology
+ """
+ 2. Add (logical) data centers to the topology
+ (each data center is one "bigswitch" in our simplified
+ first prototype)
+ """
+ dc1 = net.addDatacenter("datacenter1")
+ dc2 = net.addDatacenter("datacenter2")
+ dc3 = net.addDatacenter("long_data_center_name3")
+ dc4 = net.addDatacenter(
+ "datacenter4",
+ metadata={"mydata": "we can also add arbitrary metadata to each DC"})
+
+ """
+ 3. You can add additional SDN switches for data center
+ interconnections to the network.
+ """
s1 = net.addSwitch("s1")
- # add links between data centers
+
+ """
+ 4. Add links between your data centers and additional switches
+ to define you topology.
+ These links can use Mininet's features to limit bw, add delay or jitter.
+ """
net.addLink(dc1, dc2)
- net.addLink("dc1", s1)
- net.addLink(s1, "dc3")
- net.addLink(s1, dc4)
- # start network
+ net.addLink("datacenter1", s1)
+ net.addLink(s1, dc3)
+ net.addLink(s1, "datacenter4")
+
+ """
+ 5. We want to access and control our data centers from the outside,
+ e.g., we want to connect an orchestrator to start/stop compute
+ resources aka. VNFs (represented by Docker containers in the emulated)
+
+ So we need to instantiate API endpoints (e.g. a zerorpc or REST
+ interface). Depending on the endpoint implementations, we can connect
+ one or more data centers to it, which can then be controlled through
+ this API, e.g., start/stop/list compute instances.
+ """
+ # create a new instance of a endpoint implementation
+ zapi1 = ZeroRpcApiEndpoint("0.0.0.0", 4242)
+ # connect data centers to this endpoint
+ zapi1.connectDatacenter(dc1)
+ zapi1.connectDatacenter(dc2)
+ zapi1.connectDatacenter(dc3)
+ zapi1.connectDatacenter(dc4)
+ # run API endpoint server (in another thread, don't block)
+ zapi1.start()
+
+ """
+ 5.1. For our example, we create a second endpoint to illustrate that
+ this is supported by our design. This feature allows us to have
+ one API endpoint for each data center. This makes the emulation
+ environment more realistic because you can easily create one
+ OpenStack-like REST API endpoint for *each* data center.
+ This will look like a real-world multi PoP/data center deployment
+ from the perspective of an orchestrator.
+ """
+ zapi2 = ZeroRpcApiEndpoint("0.0.0.0", 4343)
+ zapi2.connectDatacenter(dc3)
+ zapi2.connectDatacenter(dc4)
+ zapi2.start()
+
+ """
+ 6. Finally we are done and can start our network (the emulator).
+ We can also enter the Mininet CLI to interactively interact
+ with our compute resources (just like in default Mininet).
+ But we can also implement fully automated experiments that
+ can be executed again and again.
+ """
net.start()
- net.CLI() # TODO remove this when we integrate APIs?
- net.stop() # TODO remove this when we integrate APIs?
- # start APIs (to access emulated cloud data centers)
- pass # TODO: how to reflect one API endpoint per DC?
+ net.CLI()
+ # when the user types exit in the CLI, we stop the emulator
+ net.stop()
def main():
+ setLogLevel('info') # set Mininet loglevel
create_topology1()