Strangely enough this started as a request from Tyler Bird after reviewing my Capistrano presentation. He was interested in learning how I use Capistrano to update external site dependencies, like a local cached copy of the Google Analytics JavaScript files.
Originally all I did was have this task in my Capfile, and hooked it in after the deploy:symlink task:
desc "Update local urchin.js file"
task :update_urchin, :role => :web do
run "wget -O #{current_path}/public/urchin.js http://www.google-analytics.com/urchin.js"
end
I then simply changed the configurations of the Google Analytics plugin to point to local urchin.js file.
Wow, thats simple enough, but what’s the catch?
Two things bothered me, support for the newer ga.js file, and not having access to Rails’ timestamping of assets for far future caching.
I pointed out to Tyler that I’m revisiting a lot of things we do with Capistrano and will post them here as I go along. The Analytics issue was one that bothered me constantly, so I set out to correct it.
I made my own fork of the Google Analytics plugin over at GitHub, and added support for having local copies of both the legacy and new Analytics JavaScript files, complete with Rails timestamping in the mix. I also added a rake task to help out with keeping the files up to date.
So the capistrano task I mentioned earlier would be changed to look like this now:
desc "Update local Analytics cached files"
task :update_analytics, :role => :web do
run "cd #{current_path} && rake google_analytics:update RAILS_ENV=#{rails_env}"
end
Now you can neatly update your cached copies on each deployment.
Please visit the GitHub fork for more information on the plugin itself. I’ll set up a local project page on this blog tomorrow. The whole excercise was aimed at showing how to use Capistrano for updating external dependencies, although I have to admit it got a little lost in the noise as I carried on.