Friday, June 29, 2012


That's far too many acronyms, really. What do they mean? Well, readers of this blog will understand that TDI has got nothing to do with diesel engines but is, in fact, Tivoli Directory Integrator.

MQTT? MQ Telemetry Transport - "a machine-to-machine (M2M)/"Internet of Things" connectivity protocol".

RSMB? Really Small Message Broker - "a very small messaging server that uses the lightweight MQTT publish/subscribe protocol to distribute messages between applications".

So what do I want to do with this stuff? Well, you will now know that I got myself a Raspberry Pi and I was scratching around thinking of things I'd like my Pi to do. I came across an excellent video showing how Andy Stanford-Clark is utilising his Pi to monitor and control devices around his home - it is definitely worth a look

I have no intention (yet) of trying to copy Andy's achievements as I'm quite sure I don't have the spare hours in the day! However, I was intrigued to see if I could use my favourite tool (TDI) to ping messages to RSMB using MQTT.

Step 1 - Download RSMB

Step 2 - Startup RSMB

Step 3 - Fire up a Subscriber listening to the TDI topic

Step 4 - Write an Assembly Line to use the MQTT Publisher Connector

Step 5 - Populate the output map of my connector and run the Assembly Line.
The result will be a message published to RSMB which I can see in my subscriber utility:

I can also see the RSMB log shows the connections to the server:

Of course, TDI doesn't have an MQTT Publisher Connector - I had to write one. The good news is that this was possibly the simplest connector of all-time to write. That said, it is extra-ordinarily basic and is missing a myriad of features. For example - it does not support authentication to RSMB. It's error handling is what I can only describe as flaky. It is a publisher only - I haven't provided subscriber functions within the connector. But it shows how TDI could be used to ping very simple lightweight messages to a message broker using MQTT.

So what? Sounds like an intellectual exercise, right? Well, maybe. But MQTT is a great way of pushing information to mobile devices (as demonstrated by Dale Lane) so what I have is a means of publishing information from my running assembly lines to multiple mobile devices in real-time - potentially.

At this point, though, it is worth pointing out that the development of a connector is complete overkill for this exercise (though it does look pretty).

Dropping the wmqtt.jar file that can be found in the IA92 package into {TDI_HOME}/jars/3rdparty will allow you to publish to RSMB using the following few lines of TDI scripting:

// Let's create a MQTT client instance
var mqttpersistence = null;
var mqttclient ="tcp://rsmb-server:1883", mqttpersistence);

// Let's connect to the RSMB server and provide a ClientID
var mqttclientid = "tdi-server";
var mqttcleanstart = true;
var mqttkeepalive = 0;
mqttclient.connect(mqttclientid, mqttcleanstart, mqttkeepalive);

// Let's publish
var mqtttopic = "TDI";
var mqttmessage = "This is a sample message!";
var mqttqos = 0;
var mqttretained = false;
mqttclient.publish(mqtttopic, mqttmessage.getBytes("ISO-8859-1"), mqttqos, mqttretained);

Not very complicated. In fact, very simple indeed! (The connector I developed doesn't get very much more complicated than this!)

Wednesday, June 13, 2012

Raspberry Pi, XBMC and Android

Well this is completely off-topic for me... Pi, XBMC and Android really doesn't fit with the myriad of previous posts on Identity & Access Management and IBM Tivoli security software. So for those of you who are only interested in the latter, you might as well stop reading now.

For those of you interested in how you can build your own media centre for just a few pennies, read on.

The Raspberry PI is a cred-card sized computer that plugs into your television. Having grown up with a ZX Spectrum in my younger days, I was keen to recreate the feelings I had as a teenager fiddling with Sir Clive's version of BASIC.

The Pi has an ethernet port, an HDMI slot, two USB ports, an SD card reader, a power slot and additional audio/video outputs as well as a GPIO for adding your own hardware attachments.

For my project, I just needed an ethernet cable, an HDMI cable, some form of power and an SD card to host my Operating System - Debian6.

Following the instructions provided at, I was able to flash my debian6-19-04-2012 image to my 8GB SD card. I then resized the partitions using a GParted LiveCD as attempting to deploy anything on to the image is an exercise in futility as the image provided is TINY!

I slotted the SD card into my Pi, attached the HDMI and ethernet cables and then attached my Amazon Kindle power cable and watched the lights come on and the boot sequence start.

Unfortunately, the image provided doesn't have SSH enabled by default which meant hooking up an old keyboard to the Pi and sorting that out - as such:

sudo mv /boot/boot_enable_ssh.rc /boot/boot.rc
sudo reboot

The keyboard was disconnected and it was time for some PuTTY action back on my home desktop.

Next up, I decided to install XBMC and thankfully this is a path well trodden so far. In fact, detailed instructions can be found online and it is worth following this thread on the Raspberry Pi Forum.

The following instructions are slightly more detailed and detail the approach I took. NOTE: I have placed the actual files I downloaded on to my own website so I can recreate this procedure should the images "disappear" from the original sources.

First step, install XBMC:

cd /home/pi
gunzip xbmc-bcm.tar.gz
tar -xvf xbmc-bcm.tar
sudo mv xbmc-bcm /opt
rm xbmc-bcm.tar

Next up, update the Raspberry Pi firmware:

cd /home/pi
wget {host}/

cd raspberrypi-firmware-0c3566c
sudo cp boot/* /boot
sudo cp -R opt/vc/* /opt/vc/
sudo cp -R lib/modules/3.1.9+/* /modules/3.1.9+/
sudo reboot

So far, so good. Now to install some dependencies which takes a not inconsiderable amount of time:

sudo apt-get -y install autoconf libboost-dev libass-dev libmpeg2-4-dev libmad0-dev libjpeg-dev libsamplerate0-dev libogg-dev libvorbis-dev libmodplug-dev libcurl4-gnutls-dev libflac-dev libmysqlclient-dev libbz2-dev libtiff4-dev libssl-dev libssh-dev libsmbclient-dev libyajl-dev libfribidi-dev libsqlite3-dev libpng12-dev libpcre3-dev libpcrecpp0 libcdio-dev libiso9660-dev libfreetype6-dev libjasper-dev libmicrohttpd-dev python-dev python-sqlite libplist-dev libavahi-client-dev

Next? Install the Raspberry Tools:

cd /home/pi
wget {host}/

cd raspberrypi-tools-772201f
sudo cp -R arm-bcm2708/linux-x86/arm-bcm2708-linux-gnueabi/sys-root/lib/ /usr/lib
sudo ldconfig

At this stage, we are almost finished. I wanted to make sure that everything was bang up-to-date though and threw in some reboots, just to be sure:

sudo reboot
sudo apt-get update
sudo apt-get upgrade
sudo reboot

And finally, it was time to run XBMC:

sudo LD_LIBRARY_PATH=/opt/xbmc-bcm/xbmc-bin/lib /opt/xbmc-bcm/xbmc-bin/lib/xbmc/xbmc.bin

Configuring the XBMC settings through the XBMC interface required my old keyboard to be hooked up once again, unfortunately, but this was a "one-off". I enabled the XBMC webserver and added my ReadyNAS Duo as a UPNP source for video, music and pictures.

I then downloaded the XBMC Remote software for Android to my phone, punched in the webserver details for my new XBMC installation, and hey presto - I was able to control the XBMC from my phone and enjoy watching a movie on a television that is already DLNA capable :-)

Now, I just need to move the Pi to the bedroom where there is an old television that couldn't even spell DLNA if it had the power of speech.

Cool? I think so...