The FloodLight Controller.

FloodLight is an open-source, Java-based controller maintained by OpenFlowHub.

This page is comprised of many notes that may be transient. Anything referencing links will be repeated for completeness.

Quick Links

Installation
Adding functionality
Architecture - the section most likely to change as I figure things out/discover my own misconceptions.
Floodlight/Mininet VM

Installation.

The following describes the installation of FloodLight on an Ubuntu 11.04 (natty) system. Installation is described on their ​website, but will be repeated here. If you are using SSH, You may want X11 forwarding to be able to launch Eclipse later on.

1. install the dependencies:

   apt-get install build-essential default-jdk ant python-dev git-core eclipse
   

2. pull sources from github, and build:

   git clone git://github.com/floodlight/floodlight.git
   cd floodlight/
   git checkout stable
   ant;
   

3. launching the controller - there are two ways to do this - through eclipse, or directly through java (both in the floodlight/ directory):

   java -jar target/floodlight.jar
   

or as an Eclipse project - first set up Eclipse:

ant eclipse;

then import Floodlight as a project (verbatim from the website):

• Open eclipse and create a new workspace
• File → Import → General → Existing Projects into Workspace. Then click “Next”.
• From “Select root directory” click “Browse”. Select the parent directory where you placed floodlight earlier.
• Check the box for “Floodlight”. No other Projects should be present and none should be selected.
• Click Finish.

Once imported, the controller may be run by right-clicking on Controller.java (net.floodlightcontroller.core.internal.Controller.java, found under src/main/java) and doing the following:

• Click Run→Run Configurations
• Right Click Java Application→New
• For Name use FloodlightLaunch
• For Project use Floodlight
• For Main use net.floodlightcontroller.core.Main
• Click Apply

This creates a handle for launching Controller.java as an application.

The learning switch is loaded by default. The controller listens on 0.0.0.0:6633 (host, all interfaces with an IP address).

Adding functionality.

A base tutorial can be found ​here. The steps assume that you are using Eclipse. The rough steps are the following:

1. Create a new class under src/main/java, basing it off of a template, if it exists
2. Register the module so that it is loaded at startup. This involves adding the fully qualified module name to two files:
   • net.floodlight.core.module.IFloodlightModule - list of modules recognized by the loader
   • floodlightdefault.properties - list of modules to be loaded at startup.

Architecture

• ref: ​http://www.openflowhub.org/display/floodlightcontroller/Advanced+Tutorial

The controller has two main components:

• the core, which listens to OpenFlow messages and dispatches events, and
• secondary modules which handle the events e.g PACKET_INs.

The secondary modules register with the core module when the controller is starting up. They do everything from recording certain aspects of flows to providing a RESTful API to modifying the flow tables within switches. They may also export services to leverage other modules, such as the REST API.

Some module components

• IFloodlightProviderService : Needed for listening to OpenFlow messages by registering with the FloodlightProvider.
• getModuleDependencies() : in a module, the function to indicate dependencies to the module loader e.g the IFloodlightProviderService above.
• init() : in a module, the function where contexts are defined for services that the module is dependent on. It seems to be similar to a constructor.
• isCallbackOrderingPrereq(), isCallbackOrderingPostreq() : where the module should be in the message processing chain.
• startUp() : in a module, defines external initializations associated with other modules to which it is dependent on.
• receive() : defines what a module does when it receives an event e.g. the one specified in startUp().

The Floodlight VM

This is a VM image geared towards VirtualBox containing a running floodlight instance, mininet, and wireshark.
It can easily be run on qemu/kvm after conversion to qcow2 with qemu-img convert -O and with the parameters used to run mininet.

temporary mininet info

Using with vnc: requires:

kvm-pxe ssvnc tightvncserver