Raspberry Pi! The cheap $25/$35 board with 700Mhz ARM cpu, GPU, 256 mb RAM, dual USB, ethernet and a bunch of general purpose IO pins. Looking awesome in its bare metal and firing it up is no problem. I flashed an SD card with the Raspbian “wheezy” Linux distribution. To write the image to the SD card I used Win32DiskImager from a PC with SD card slot.
After attaching USB keyboard, network cable and HDMI it comes to life by using a micro USB as power supply. The diods flashes and even X runs quite smooth on this limited hardware.
However, after playing around I soon realised I will be much more comfortable working on a distance from my ordinary desktop machine. So how to enable ssh?
A lot of tutorials talks about something as simple as this to enable ssh daemon on boot.
sudo mv /boot/boot_enable_ssh.rc /boot/boot.rc
Sorry, I have no such files in my /boot directory. Furthermore, when trying to start the ssh daemon with
it refuses to start. Clues in the startup log are
Could not load host key: /etc/ssh/ssh_host_rsa_key Could not load host key: /etc/ssh/ssh_host_dsa_key
Why these are corrupt I don't know, but it's easy to regenerate them.
ssh-keygen -t rsa1 -f /etc/ssh/ssh_host_rsa_key
ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key
Make ssh daemon start permanent
sudo update-rc.d ssh defaults
A sudo reboot and everything seems ok.
Now, my mission for tonight was to get a web server running on the chipset. Here's what you need to do to make Tomcat 7 run.
Tomcat obviously need Java:
sudo apt-get install openjdk-6-jdk
And you obviously need a potent editor
sudo apt-get install vim
Clean up your installs to save some space on the SD card
sudo apt-get clean
Now, download, unpack and install Tomcat
tar xzf apache-tomcat-7.0.28.tar.gz
Add a user to the authorization file, directly below <tomcat-users> add
<user username="system" password="raspberry" roles="manager-gui"/>
Now start Tomcat
sudo sh startup.sh
Nice! From your PC (or via a browser on the Pi) surf against the Tomcat console.
(Figure out the ip address via for example ifconfig)
It takes a short while to warm up the server but then you can login via Manager App. Now, it's business as usual. Upload a war archive and you have a nifty web server running you web application, for $35!