Add some metrics to your Rakefiles

Rakefile

task :environment do
  puts "environment"
end

namespace :metrics do
  task :before do
    # Get time task started
    @started_at = Time.now.to_i
  end

  task :after, :name do |t, args|
    # Do something with the time taken
    puts "Task #{args[:name]} - took #{Time.now.to_i - @started_at}s"
  end
end

namespace :foo do
  task :bar => :environment do
    puts "bar"
    sleep(rand(5))
  end

  task :quick => :environment do 
    puts "quick"
  end
end

# Wrap each task in the foo namespace in with metrics before/after
Rake.application.tasks_in_scope(Rake::Scope.new(:foo)).each do |task|
  task.enhance(["metrics:before"]) do
    Rake::Task["metrics:after"].invoke(task.name)
  end
end