I have written a plugin for the continuous integration server Hudson which uses a metric-fu rake task at its core to build and present graphs representing different metrics over successful builds.
It currently supports:

• Flog (Complexity)
• Flay (Duplication)
• Rcov (Code coverage)

The source is available on Github:

http://github.com/josephwilk/rubymetricfu

Installing

Currently all Hudson’s plugins are stored in something called SVN. Being more of a GIT myself you have to manually install the plugin rather than using the automatic Hudon GUI install method.

Install steps:

1. Ensure you have the Ruby and Rake Hudson plugins installed.
2. Follow the metric-fu installation guide (http://metric-fu.rubyforge.org/)
3. Ensure project code has a metrics:all rake task (auto added when you require metric-fu)
4. Download the rubymetricfu.hpi plugin file
5. Copy the file into your plugins folder within you Hudson install. Hudson’s default is ~/.hudson/plugins
6. Restart hudson
7. Go to the ‘configure’ link for a project and select the Ruby Metric-fu report option (see below)
8. (Optionally) Pick which Rake version you want to use.

Future

• Futher metrics to graph:
  • Roodi (design issues)
  • Reek (Code smells)
  • Saikuro (cyclomatic complexity)
• Configure which metrics you want on your project page.
• Create a Crap4R meter using Rcov and Flog (Similar to Crap4J).
• Better integration with the html reports generated by metric-fu.