09 Nov 07
Bubble, Bubble, Build's In TroubleYour software is being automatically built and tested on a schedule. It even sends you an email when the code doesn’t compile or pass its tests. You’re certainly ahead of most projects, but email is just so 90s. Even if you could manage to find those build failure emails amidst all that spam, you’re reading yesterday’s news. Indeed, you may already be ignoring the status of the scheduled build.
The Monitoring chapter of the book offers alternative, in-your-face, worth-getting-up-for-in-the-morning techniques for monitoring scheduled builds. The most popular technique came by way of a story contributed by Alberto Savoia. He describes how his project uses red and green lava lamps to radiate the status of their scheduled build. Better yet, those lamps are controlled using X10 devices such as those used to turn on your household lamps so that you don’t arrive home to a dark house.
Well, as you might imagine, I could hardly wait to build my very own build-monitoring lava lamp kit. And as bonus material for readers of the book, I’ve crafted a bit o’ software that integrates with CruiseControl. So now you too can enjoy red and green bubbles on your project!
Bill of Materials
To get started, you need some automation gear. Think of these gadgets as this year’s essential project accessories:
- 4-Piece Firecracker
This kit includes:
- 1 Firecracker Computer Interface
- 1 Transceiver Module
- 1 Lamp Module
- 1 Palm Pad Remote Control
(Props go to the folks at x10.com for supporting this project by supplying me with a complimentary kit. It all fits in a wee box, so I can carry it from project to project.)
With that kit, you can control two lava lamps — one plugged into the transceiver module and the other plugged into the lamp module. You can optionally purchase another appliance module if you want to control two appliances. For example, you might want your build process to turn on a coffee pot when the build fails and then kick start your margarita machine when the build is fixed.
- 2 lamps, preferably the kind that boil red and green lava
I used the Hot Rock Lite F/X (yellow earth/blue liquid and red earth/purple liquid). Note for legal purposes that these lamps (shown in pictures below) are not LAVA(R) brand motion lamps, but those will work just as well.
Cost: $9.99 each at Target or Walmart
Automation X10 software
It’s an open source Java library that includes the CruiseControl plug-in, an API to make your wildest X10 dreams come true, detailed instructions, and an ever-so-useful collection of tests.
Way down deep, the library uses the Java Communications API to send bits out over the serial port and into the Firecracker Computer Interface. (Linux users will need the RXTX implementation). Michel Dalal’s Java X10 CM17A API library, an implementation of the FireCracker (CM17A) Communications Specification, is used to send out the correct 1s and 0s in response to human-friendly commands. Many thanks to him for doing all the low-level bit twiddling and sharing the goodies with us!
Cost: Free to readers of Pragmatic Project Automation
Assembling the Kit
With that hardware in hand, you’re ready to start the assembly process. The Firecracker Automation System includes instructions written for your average home electronics consumer, so your average computer/network geek should have no trouble. I’ll spare you all the gory details and instead run through a quick visual tutorial of my setup.
Start by plugging the Firecracker Computer Interface into a serial port of your scheduled build machine:
This little gem sends a wireless signal from the computer to the transceiver module. Notice that you don’t lose the serial port. You can plug another serial device into the back of Firecracker Computer Interface.
Next, plug the transceiver module into any wall outlet within your electrical wiring system. Then turn on the lamp you want the build process to light up when the build fails (the red lamp) and plug it into the transceiver module:
See that antennae on the transceiver? The transceiver picks up the RF signal sent by the Firecracker Computer Interface connected to the computer, converts it into an X10 signal, and broadcasts the X10 signal across the electrical wiring system.
Every X10 module is uniquely identified by a house code (A-P) and a unit code (1-16). By default, the transceiver is configured to listen on "A1". So when the Firecracker Computer Interface sends a signal that tells module "A1" to turn on, the device that’s connected to the transceiver—the red lamp—is turned on.
Next, plug the lamp module into a wall outlet and set its house and unit code to "A2". Then turn on the lamp you want the build process to light up when the build passes (the green lamp) and plug it into the lamp module, like so:
When the Firecracker Computer Interface sends a signal instructing the "A2" module to turn on, the transceiver picks up the signal and broadcasts it out over the electrical wires. The lamp module hears the signal and turns on the green lamp.
That’s it for assembly!
At this point it’s a good idea to make sure you can turn these lamps on and off at will using the free software (separate download) that emulates the Palm Pad Remote Control. It sends signals through the Firecracker Computer Interface, so it’s a good sanity check that you have everything hooked up correctly.
Installing the Software
The README file describes how to install and test the software in detail. The final step is to register the CruiseControl plug-in that effectively wires up the lamps to indicate the status of each CruiseControl build cycle. Just to demonstrate how easy that is, here’s the XML you need to add to CruiseControl’s config.xml file:
<plugin name="x10publisher" classname="com.pragauto.X10Publisher"/> <publishers> <x10publisher port="COM1" passDeviceCode="A2" failDeviceCode="A1" /> </publishers>
Edit the attributes of the <x10publisher> element as necessary for your serial port and device codes. A complete config.xml file is included in the project as a reference.
Bubbles While You Work
Once you’ve fired up CruiseControl and a build succeeds, you’ll see something like this on the console:
BUILD SUCCESSFUL Total time: 10 seconds [cc]Jul-08 16:56:53 Project - Project dms: merging accumulated log files [cc]Jul-08 16:56:53 Project - Project dms: publishing build results [cc]Jul-08 16:56:53 X10Publisher - Turning pass device (A2) on; fail device (A1) off ... [cc]Jul-08 16:56:56 Project - Project dms: idle [cc]Jul-08 16:56:56 Project - Project dms: next build in 1 minutes
At that point, the green lava lamp should turn on. Bask in that pleasant glow for a moment. When the lamp gets warmed up, you’ll get entertained by happy, green bubbles:
And then at some point somebody might check in code that causes the build to fail. (Hey, it happens to even the best programmers once in a while.) Here’s the early warning sign that the scheduled build is in trouble:
Eek! Notice that the ambient light in the red lamp goes on immediately. It will take a while for the red lava to heat up and start to boil. In the meantime, there’s work to be done. When you check the CruiseControl log, you’ll see something like this:
BUILD FAILED file:C:/work/dms/builds/checkout/dms/build.xml:77: Tests failed! Check test reports. Total time: 5 seconds [cc]Jul-08 16:58:20 Project - Project dms: merging accumulated log files [cc]Jul-08 16:58:20 Project - Project dms: publishing build results [cc]Jul-08 16:58:20 X10Publisher - Turning pass device (A2) off; fail device (A1) on... [cc]Jul-08 16:58:23 Project - Project dms: idle [cc]Jul-08 16:58:23 Project - Project dms: next build in 1 minutes
If it takes too long to fix the build, the red lamp will start to get angry:
The object of the game is to keep the green lamp glowing. :-)
Hearing the Build Break
You may have noticed that when the transceiver module turns on and off it makes a fairly loud snapping sound. That sound is caused by the mechanical relay inside. (The lamp module doesn’t make that sound, I suspect because it’s a low-current device that doesn’t use a mechanical relay.)
This audible feedback turns out to be quite handy if your team is working in close quarters. The "snap" could be yet another sound in your project soundscape. By plugging the red lamp into the transceiver module (A1), you’ll hear that snapping sound just before the red lamp turns on. So if you’re heads down (without headphones), the sound will alert you to a build failure. Indeed, you’ll hear the build break!
Important Safety Notes
These lamps get insanely hot. If you don’t let them cool down for at least five minutes before touching the glass, you’ll find out just how hot. (Yes, even the green one is hot.)
The instructions for my lamps note that they perform best if operated for less than ten hours at a time. Your local fire marshal would certainly agree. But who will remember to turn off the lamps at the end of every programming day? Well, that’s a job for the ol’ computer. Just write a shutdown program that uses the Pragmatic Automation X10 software to turn off the lamps. For example:
new X10Device("COM1", "A1").off(); new X10Device("COM1", "A2").off();
Then schedule an at or cron job on the scheduled build machine that runs the shutdown program at some hour of every evening, and another program that turns the lamps on every morning.
What About My Macintosh?
The Firecracker Computer Interface plugs into a serial port. Modern day Macintosh computers don’t have a serial port. Sadly, none of the USB-to-serial converters I tried worked with the Firecracker Computer Interface. (I’d love to hear otherwise.)
You can purchase X10 kits that plug into USB, but I chose to use the Firecracker kit because it’s relatively cheap and it’s what is described in the book. Thankfully, by writing and testing most of this software against a mock device, I was able to do the majority of the development on my PowerBook. :-)
It’s relatively easy and inexpensive to make build monitoring a spectator sport. Put the lava lamps in a highly-visible area of your project and use them as visual (and audible) feedback devices, and to show off your programming prowess, of course. And that’s just the beginning. You can use any appliance to monitor anything that’s valuable to your team.
Are you using feedback devices to spice up your project? If so, please share your story.