Interfacing Trema with other application

[Bao Tri Nguyen]

Hi developers and community!

I'm new to OpenFlow and Trema. I've been going through the tutorials and managed to write a simple controller in Ruby with some working functions.
Currently, I'm using virtual machines with OpenvSwitch to model the actual network.

May I know if there is a way for other application to communicate with Trema?
In my case, I need to let my web server/ application to inform Trema controller to set new flows.

Thank you for reading this.

Best regards,
Nguyen Bao Tri

[nickkaranatsios]

Hello Nguyen

One way for you to do could be for example set a periodic timer in your ruby controller and poll for changes from your web-server and perform your desired action.

You could for example use sockets to communicate with your web server or use any distributed K/V store, redis could be one.

Regards

Nick Karanatsios

PS. The trema c library provides the ability to set an external callback that would be called from inside the event loop but unfortunately this feature has not been implemented in ruby controller.

[Bao Tri Nguyen]

Hi Nick (I assume)

Thank you for your reply! I did a quick search and think redis will be my solution. However, I'm curious about using socket too.
I hope it will not be too greedy if I come back with more specific technical questions on the actual implementation.

Have a nice day!

[Bao Tri Nguyen]

Hi everyone!

As Nick suggested, I've been implementing Redis and initial testing shows that it works! :D

My web server is using LAMP with Predis library, running concurrently with a Redis server.
On the controller side, redis-rb will do the trick.
Both of these elements can now communicate with each other through write/read to Redis server.
Thanks Nick!

Cheers,
Nguyen Bao Tri