What is Cucumber?

Cucumber is a Behavior Driven Development (http://bit.ly/r7L4) framework for integration tests.

Cucumber uses plain-text descriptions as automated tests. The language used is called Gherkin.

The plain-text descriptions can be written by anyone, but usually they are written by the management team of the project who will do a role play for each of the users who use the system. The QA team would usually be involved in every step of creating the descriptions.

The honey moon period

You have started to write your application, writing a few cucumber descriptions, a little RSpec. You have your tests running with AutoTest and even have a notification from Growl (on a mac) to tell you that your tests have passed, but this can be short lived.

As your application grows, so do the amount of cucumber tests. This means it takes more time for the tests to run, and every time you make a change to your code, autotest will run all of your tests again. This can take a lot of time! Autotest is good, but it is pretty dumb!

Lazy Loading

But wait! There is a tool to solve the problem that Autotest has, its called Cucover (http://bit.ly/dg3Je3).

Cucover is a think wrapper for Cucumber, that well makes it lazy. It works by using RCov to detect which parts of the code have changed, Cucover will then only rerun the scenarios that are affected by the code changes.

You can install Cucover by using this command:

sudo gem install mattwynne-cucover --source http://gems.github.com

Lazy loading can also be used for loading web services, this is so time is not wasted loading up services that a feature does not require.

Handy Cucumber features

Another way to speed up your tests during development is to use the handy features built into cucumber.

Tagging: $ cucumber –tags @media

Tagging is used to run certain scenarios.

Filenames: $ cucumber visitor_*

You can name files with a naming convention and only run those files using a regex.

Subsystems: $ cucumber admin_suite/*

Put each of your different features into folders and get cucumber to run all features in that folder.

Continuous Integration

Another way to rocket fuel your cucumbers is to use Continuous Integration. There are many continuous integration systems out there, here are some:

• Hudson
• Team City
• Integrity
• Bamboo
• Run Code Run
• CI Joe
• CruiseControl.rb
• Cerberus

Spork

Spork (http://bit.ly/1zUlXg) is Tim Harper’s implementation of test server (similar to the script/spec_server provided by rspec-rails), except rather than using the Rails constant unloading to reload your files, it forks a copy of the server each time you run your tests. The result? Spork runs more solid: it doesn’t get corrupted over time, and it properly handles modules and any voo-doo meta programming you may have put in your app.

Divide and Conquer

One way to divide your application is to use Rails Engines. Rails Engines are mini Rails applications that are run from the vendor/plugins directory, you can write separate cucumber tests and run these against your rails engine.

Another way is to use Service Oriented Architecture (http://bit.ly/PTT-SOA) by using this design principle, you can separate your cucumber tests for each service of your application.

Axing Treetop

Treetop is the parser that Cucumber uses to read the plain-text descriptions, but it is well….a bit slow.

This is where Ragel comes in.

Here are some statistics comparing Regal and Treetop:

To parse 1257 Scenarios when using tags:

Treetop took 60 seconds

Regal took 5 seconds.

Regal is currently being integrated with Cucumber, but you can get it now by running:

sudo gem install gherkin

Looking to the Cloud

Amazon EC2 is a good way to use cloud computing to run your cucumber tests.

To run 1257 steps for a http://www.songkick.com/ on one build server took 4 hours.

On 19 Amazon S3 instances it took 13minutes and 40 seconds.

The key is to have an image created so that you can just startup as many instances as you need, so that they are all setup and ready to receive tests.

To use multiple servers to run your tests you can use a tool called Testjour.

Testjour can distribute your tests over multiple servers or if you like, multiple cores of your build machine.

To run 254 Features, and 1257 steps, took 4 hours on one build server.

When using 3 servers and Testjour, it took 2.

The only problem with Testjour is that its poorly documented, it says it can do things that it can’t.

It is also very fragile!

This is how Testjour works, it first uploads your code to all of the slave servers.

Next it uploads the tests to a Redis Work Queue, this then sends the tests to which ever slave servers are free to be tested against the application.

Joseph’s company spends around $80 a day on Amazon EC2 instances, but this saves dividends

Useful tip

To see how long your cucumber tests take to run, you can run the following command:
cucumber -format usage features/

sudo apt-get install hfsplus hfsprogs hfsutils

This is so Linux can read the filesystem on the harddrive.

Now, to find out which drive is our harddrive we need to use a utility called parted, this will show us all the drives attached and their partitions. You have to be a superuser to use parted.

Start up parted:

sudo parted

Now print a list of all the drive:

print all

Here is the output for the harddrive I wish to mount:

Model: WD 10EACS External (scsi)
Disk /dev/sdc: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
1 20.5kB 210MB 210MB fat32 EFI System Partition boot
2 210MB 1000GB 1000GB hfsx Untitled

The output tells us where the disk is: /dev/sdc and the number of partitions.

I want to mount the second partition as thats the one with all my data on it, to mount the second partition you add a 2 to the end of /dev/sdc to say you want the second partition:

sudo mount -t hfsplus /dev/sdc2 /mnt

Now the drive is mounted, all the files on the drive will be available in /mnt.

First, download the minimal install of Ubuntu Karmic Koala (12.1mb x86 12.2mb x64)

Download either the x86 or x64 version dependent on your hardware.

Once the disk image has downloaded either burn it to CD or use UNetbootin to boot from a USB pen drive.

Reboot the computer you wish to install xbmc on, and boot from the CD or USB pen drive, you may need to change some settings in your bios to boot from CD or USB.

Start the installation, and follow the onscreen instructions to set your language and keyboard layout. Enter a username and password for your main account, for this I entered xbmc.

The installer will ask you what packages to install, scroll down to OpenSSH Server and press SPACE, then press ENTER to continue.

After the installation has completed, your computer will reboot.

When you get to the login screen, login with the username and password you entered.

Once you have logged in we need to add the PPA for XBMC.

sudo nano /etc/apt/sources.list

And these lines to the end.


deb http://ppa.launchpad.net/nvidia-vdpau/ppa/ubuntu karmic main
deb-src http://ppa.launchpad.net/nvidia-vdpau/ppa/ubuntu karmic main
deb http://ppa.launchpad.net/team-xbmc/karmic-ppa/ubuntu karmic main
deb-src http://ppa.launchpad.net/team-xbmc/karmic-ppa/ubuntu karmic main


We will need to add the a key to aptitude to stop it complaining.

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 64234534 40618B66 CEC06767 318C7509 91E7EE5E

Sometimes the key server will return this error:
gpg: keyserver timed out
gpg: keyserver receive failed: keyserver error

A trick I found was to ping the key server address, after it responded try and run the previous command again:

ping keyserver.ubuntu.com

Now we need to update aptitude.

sudo apt-get update


Now we will install the NVidia drivers:

sudo apt-get install nvidia-glx-190

You will need to enter your password again.

Next, we want sound for our media, so we will install some sound drivers.

sudo apt-get install linux-sound-base alsa-base alsa-utils


Your user needs to be added to the sound group.

sudo usermod -a -G audio xbmc


Change xbmc to the username that you entered.

The sound level will be set to zero, to change the volumes we need to enter the sound mixer.

sudo alsamixer


Use you up and down keys and set the volumes to the maximum they will go. Press the right key until you get to IEC958, EC958 D, EC958 1 and press M on each of them to un-mute them.

Press ESC to quit out of the mixer.

To make alsa save the volumes run.

sudo alsactl store 0


Now we can install XBMC.

sudo apt-get install xbmc xbmc-skin-* xbmc-eventclients-* xbmc-scripts-*


This will install xbmc, all the skins and eventclients.

Now X will need to know about your monitor, so run:

sudo nvidia-xconfig

XBMC will need to control power settings of the computer:

sudo apt-get install pm-utils policykit


And give your user access to these power features:

sudo polkit-auth --user xbmc --grant org.freedesktop.hal.power-management.suspend
sudo polkit-auth --user xbmc --grant org.freedesktop.hal.power-management.hibernate
sudo polkit-auth --user xbmc --grant org.freedesktop.hal.power-management.reboot
sudo polkit-auth --user xbmc --grant org.freedesktop.hal.power-management.shutdown
sudo polkit-auth --user xbmc --grant org.freedesktop.hal.power-management.reboot-multiple-sessions
sudo polkit-auth --user xbmc --grant org.freedesktop.hal.power-management.shutdown-multiple-sessions


Again you will have have to change –user xbmc to the username that you entered in the installation.

Now the last thing to do is make XBMC launch at startup.

sudo nano /etc/init/tty1.conf


Change the line

exec /sbin/getty 38400 tty1


To

exec /bin/login -f xbmc < /dev/tty1 > /dev/tty1 2>&1

Next we need to get Ubuntu to clear the screen and start X:

nano ~/.bash_profile


And add these lines to the file:

case "`tty`" in
/dev/tty1) clear && startx &>/dev/null;;
esac


Now we need to tell X to start XBMC:

nano ~/.xsessionrc


Add the lines:

exec xbmc --standalone

This next step is OPTIONAL, to hide all the information about what is being loaded, we shall install a usplash boot screen.

sudo apt-get install usplash libusplash-dev usplash-theme-xbmc-*


Once the splash screen installation has completed we need to select a splash screen:

sudo update-alternatives --config usplash-artwork.so


Enter the number of the splash screen you wish to use, find examples below:

Pulsating Logo
Spinner Black
Spinner Blue
XBMC Logo

All the previews where created by DU-Duke

Next set the screen resolution of your tv in the usplash settings:

sudo nano /etc/usplash.conf


And add these lines:

resx=1920
resy=1080


My TV is 1080p, so the settings above will suite yours if it is full HD, for 720p enter:

resx=1280
resy=720


To make the new splash screen active run:

sudo update-initramfs -u

Now reboot your computer:

sudo reboot


When the computer restarts, you should see the splash screen you selected, and XBMC should boot up.

Now, go into XBMC’s Videos settings and select VDPAU for the render mode (if your graphics card supports it) and edit the Sound settings:

Audio Output: Digital
AC3: Off
DTS: Off
Audio Capable Device: plughw:hdmi
Passthrough Output Device: hdmi
Downmix: On


And that’s it, you should have a fully functional media centre running the latest version of Ubuntu and XBMC.

As this is an alpha version, you will need to perform some updates now and again until the final release is out.

To so this, ssh into your computer and update it:

ssh xbmc@your media centre IP
sudo apt-get upgrade


Now I can’t take all the credit for this, I have collected some information from other sources and put them together from here:

http://xbmc.org/forum/showthread.php?t=53812
http://xbmc.org/forum/showthread.php?t=38804

Thanks to jonassw from XBMC forums, who suggested using the latest version of the NVidia drivers.

I know the blog has been down for a long time, only displaying the nice words of the default Apache page, but rest assured I am back! But this time im going to be using this blog for iPhone development instead of Rails.

I have been writing some iPhone applications recently and have discovered some good tips that I want to share.

With the things I wanted to do there were not very many resources out there to help me, but I figured them out and I am going to share the wealth!

Im working on a new design for the blog, so watch this space!