X-Git-Url: https://osm.etsi.org/gitweb/?a=blobdiff_plain;f=emuvim%2Fexample_topology.py;h=109808cbfdc6de6c118655ffb146c60c450c35e3;hb=7aae68563f4ca72f321bd264215f6a58dec6c346;hp=f2be310e457ef163f946ca36f2658edb314014c7;hpb=cbcd4c2d984a354e88febdaa368d53a3e6881c72;p=osm%2Fvim-emu.git

diff --git a/emuvim/example_topology.py b/emuvim/example_topology.py
index f2be310..109808c 100644
--- a/emuvim/example_topology.py
+++ b/emuvim/example_topology.py
@@ -2,37 +2,102 @@
 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 dcemulator.net import DCNetwork
+from api.zerorpcapi import ZeroRpcApiEndpoint
 
 logging.basicConfig(level=logging.DEBUG)
 
 
 def create_topology1():
-    # initialize network
+    """
+    1. Create a data center network object (DCNetwork)
+    """
     net = DCNetwork()
 
-    # add data centers
+    """
+    2. Add (logical) data centers to the topology
+       (each data center is one "bigswitch" in our simplified
+        first prototype)
+    """
     dc1 = net.addDatacenter("dc1")
     dc2 = net.addDatacenter("dc2")
     dc3 = net.addDatacenter("dc3")
     dc4 = net.addDatacenter("dc4")
-    # add additional SDN switches to our topology
+
+    """
+    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
+
+    """
+    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)
+    # 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 support 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():