Installing Metric_Fu on Centos/Red-Hat Linux

July 22, 2009

To gain the benefit of integrated code-quality analysis within my continuous integration process for my Ruby projects, I’ve been integrating the excellent Metric_Fu package by Jake Scruggs. I’ve now completed an installation on OS-X, CentOS and Red-Hat where I had some quirks to resolve on CentOS and RedHat. This post provides my view on the best install procedure I can offer.


First the underlying OS package pre-requisites…

sudo yum install libxml2           => v2.6.26-
sudo yum install libxml2-devel     => v2.6.26-2.1.2
sudo yum install libxslt           => v1.1.17-2
sudo yum install libxslt-devel     => v1.1.17-2
sudo yum install ImageMagick       => v6.2.8.0-3.el5.4(see note)
sudo yum install ImageMagick-devel => v6.2.8.0-3.el5.4

Note the version of the ImageMagick package I have installed. There is a version depenency here with the rmagick gem which is installed in the next section. As far as I can see, for this version of the ImageMagick package, you must install the v1.x gem. As such I installed the highest version of the gem v1.15.17 below the v2.x.x baseline. If you have later versions of this ImageMagick package then I believe you can avoid this particular issue.

The TrueType Fonts dependency…

The rmagick gem has an installation dependency on the the presence of a set of true-type fonts in the base OS installation. On both the CentOS and RedHat installs I have done, this issue has been present. So before we go ahead and install the gems, we need to rectify this issue.The dependency relates to the presence of the /usr/share/fonts/default/TrueType folder which needs to be created with the following steps. (Note – you don’t need to install these fonts if you already have TrueType fonts installed – in which case skip to the next section).

yum install rpm-build wget
rpm -ivh cabextract-1.2-1.i386.rpm 
rpmbuild -ba msttcorefonts-2.0-1.spec
rpm -ivh /usr/src/redhat/RPMS/noarch/msttcorefonts-2.0-1.noarch.rpm
cd /usr/share/fonts/default
ln -s /usr/share/fonts/msttcorefonts/ TrueType

Now the Gems…

Then install the gems:

sudo gem sources -a
sudo gem install jscruggs-metric_fu

Note at this point one of the installed depenencies, the ‘flog’ gem at v2.1.2, has an issue that will prevent it from running. I have explicitly modified the following file to get this to work:

vi /usr/local/lib/ruby/gems/1.8/gems/flog-2.1.2/bin/flog

Change the line: flogger.flog_files ARGV to flogger.flog ARGV and save the file. This is only a quick-n-dirty solution to get the flog integration to work within metric_fu.

sudo gem install reek
sudo gem install roodi
sudo gem install gruff
sudo gem install rmagick -v 1.15.17

When these gem installations complete you’re now ready to play with Metric_Fu. For more information on next steps refer to this article about some more version specific fixes or Jakes Metric_fu home.

Ruby Code Quality and Metric_Fu

July 9, 2009

I’ve been putting together a continuous integration framework for my Ruby projects and was very pleased to find the great work by Jake Scruggs ( ) by the name of Metric_Fu. On the whole this aggregation of tools covers all the key ‘quality’ bases and generates some elegant graphical reports that can be simply published alongside other build artifacts in CruiseControl.rb for example. On the whole the installation is very simple, but I hit some issues with the code and had to apply some class method overrides to get it to work.


My base environment is OSX 10.5.7, Ruby 1.8.6, Gem 1.3.3. I installed the gems jscruggs-metric_fu (1.1.1), rcov (, flog (2.1.2), flay (1.3.0), reek (1.1.3), roodi (1.4.0) and Saikuro (1.1.0). Following the instructions at I was complete in short order, and ran the rake task as per the example.

The first problem I hit was a method naming issue where the a Flog#flog_files method was being called which didn’t exist in the versions I was using. I ended up with a quick-n-dirty fix which involved amending the /gems/flog-2.1.2/bin/flog script to remove the call to flog_files, replacing it with the correct method name flog:

flogger = options
flogger.flog ARGV

Second problem I hit was some floating point and divide-by-zero issue in the MetricFu::Generator#round_to_tenths method. I don’t profess to understand the core issue here, but the value of ‘NaN’ was appearing in the calculation – so I added a ‘very’ primitve override to filter this condition (elegance is not my middle name I you hadn’t realised already):

module MetricFu
  class Generator
    def round_to_tenths(decimal)
      decimal=0.0 if decimal.to_s.eql?('NaN')
      (decimal.to_i * 10).round / 10.0

Next I hit an issue with rcov not returning any results into the dashboard? I checked this out and located an error in the rcov.txt file generated as part of the execution. This simply informed me that the rcov commandline generated within the metric_fu rcov generator class was incorrect. After a little experimentation I worked out that the –include-file parameter was the issue…so I again redefined the problematic class method in my Rakefile to remove this issue:

Module MetricFu
  class Rcov
    def emit
        FileUtils.rm_rf(MetricFu::Rcov.metric_directory, :verbose => false)
        test_files = FileList[*MetricFu.rcov[:test_files]].join(' ')
        rcov_opts = MetricFu.rcov[:rcov_opts].join(' ')
        output = ">> #{MetricFu::Rcov.metric_directory}/rcov.txt"
        #PROBLEM: `rcov --include-file #{test_files}  #{rcov_opts} #{output}`
        `rcov #{test_files}  #{rcov_opts} #{output}`
      rescue LoadError
        if RUBY_PLATFORM =~ /java/
          puts 'running in jruby - rcov tasks not available'
          puts 'sudo gem install rcov # if you want the rcov tasks'

Next I hit a problem when modifying my declared MetricFu::Configuration object to change the location of the outputs of the analysis, to reduce the pollution in my project folder hierarchy (yep…I probably do have some deeper issues). I had added the following lines to the sample provide by Jake: do |config|
  config.base_directory = ENV['CC_BUILD_ARTIFACTS'] || 'quality'
  config.scratch_directory = File.join(config.base_directory, 'scratch')
  config.output_directory = File.join(config.base_directory, 'output')
  config.data_directory = File.join(config.base_directory, '_data')

With this new folder structure I also had to add a tweek to the Saikuro configuration entry in the same sample, to make sure the Saikuro outputs are picked up by the report aggregator. Without this tweek I was just getting a blank Saikuro template page offered by Metric_Fu:

(Ignore the space between the colon and the ‘o’ – it’s giving me smilies for some reason)

config.saikuro  = { : output_directory => 
                              File.join(config.scratch_directory, 'saikuro'), 

This change caused a failure in the MetricFu::Graph#generate method – which on closer inspection appeared to be hardwired in expecting a depth of 3 folders in the locations specified for these outputs? So again I re-declared this class in my Rakefile to make the specific change necessary to support any level of nesting. This fixed the problem and my folder feng-shui returned to equilibrium…mmmmmmm.

Module MetricFu
  class Graph
    def generate
      puts "Generating graphs"
      Dir[File.join(MetricFu.data_directory, '*.yml')].sort.each do |metric_file|
        puts "Generating graphs for #{metric_file}"
        #PROBLEM: date = metric_file.split('/')[3].split('.')[0]
        date = metric_file.split('/').last.split('.')[0]
        metrics = YAML::load(
        self.clazz.each do |grapher|
          grapher.get_metrics(metrics, date)
      self.clazz.each do |grapher|

So my installation of metric_fu works perfectly now and I’m very impressed with the output it’s providing so long as I don’t dwell too much on the fact that it’s telling me my code quality is somewhere between criminal and insane !!!

I hope these notes may help others experiencing similar frustration in trying to get the install working…and again my thanks to Jake Scruggs for this piece of goodness.

Cheers all !