New blog

After just a few short week, we have gotten fed up with the limitations of having our blog hosted by wordpress.com and decided to host our own. Our new blog is at http://devver.net/blog. Please update your reader and sorry for the inconvenience.

Using Ruby to configure EC2 instances: a lesson learned

On Tuesday, we had Mike Culver from Amazon give a great talk about Amazon’s web services. We had pretty much decided on using AWS for Devver, but Mike’s talk convinced us even more.

So for the past few days we’ve been porting our code to work with EC2 . We’ve also been building scripts that will configure the machine instances on boot.

When you’re using EC2, you can store custom machine images, but you really don’t really want to be saving a new image for every tweak you make to the machine. It’s a lot more flexible to just save a basic image and give the instance a script to run when it boots, like this:

ec2-run-instances [some-image-name] -f config.rb

In this example, I’m passing a Ruby script, but you can pass any type of file at all.

I found a couple of great tutorials, but unfortunately they didn’t do quite what I wanted, so I hacked up my own solution. It’s just a few lines in the /etc/rc.local file (which runs after the machine boots) that grabs the config.rb file and runs it.

Unfortunately, for some reason, my Ruby script was not getting run. After a painfully long debugging session, I figured out that the environment had not been configured for RubyGems when my script was run, so my ‘require’ statements were breaking the code. The key lesson is that no matter what language you’re using, /etc/rc.local is running in a different environment than a logged-in user, so environment variables like PATH (and in this case, RUBY_OPT) will not be set up the same way.

Anyway, here’s the code I added to my /etc/rc.local file:

# AMI configuration code, based on code from
#http://developer.amazonwebservices.com/connect/entry.jspa?externalID=1085&categoryID=100 

# grab the file from Amazon's web service. Yes, this IP address is always the same
/usr/bin/wget http://169.254.169.254/latest/user-data -O /tmp/payload.rb

# if wget error code is 0, there was no error
if [ $? -eq 0 ]; then
  if [ -e /tmp/payload.rb ]; then
    # DON'T forget the -rubygems option! You need it if you call 'require' in your config code
    /usr/bin/ruby -rubygems /tmp/payload.rb
  else
    echo "rc.local : No payload.rb script to run"
  fi
else
  echo "rc.local : error retrieving user data"
fi

I hope that helps anyone out there starting to play with EC2…

What Is Common Ruby Development?

Since we are working on development tools initially focused on Ruby developers, we wanted to get a better picture of what is normal in Ruby development. We thought it would be good to make a short informal survey and collect the results, which we plan to share back with the Ruby community (aggregated and anonymous). We are hoping to learn a little bit more about the average size of a project, testing practices, web frameworks, and development environments.

Feel free to pass the survey link on to other Ruby hackers you know in the community. We would appreciate any additional feedback so feel free to contact us. We hope that what we learn can help us to build some tools that will help make Ruby hackers lives a little bit easier (as if it isn’t already made easy enough by comparison to some languages… ha).

So if you have some time, please take the Devver Ruby Developer Survey. Feel free to take this even if Ruby isn’t your primary language as we hope to be able to bring our tools to other languages in the future.

Sunday Funday*

* Note: this phrase only applies if you’re like us and consider writing code all day “fun”

We’ve survived our first week of TechStars. So far, so good. We’ve had the opportunity to meet tons of great founders and mentors this week. The only problem is that with sessions and meetings every day, we haven’t had as much time as we’d like to actually write code. We wanted to do more Saturday, but got caught up with errands and a friends birthday in Denver. Luckily, we’ve got nothing going on today, so we’re going to crank out a lot of code. So much for that “day of rest” stuff.