Scan many rails log files for a particular query parameter for a particular action

gistfile1.rb

require 'uri'
require 'csv'
i = 1
files = Dir.glob("app0*/*.log*")

data = files.map do |filename|
  puts "Reading #{filename} #{i}/#{files.count}"
  i = i + 1
  File.readlines(filename).select do |line|
    line.match /GET \"\/api\/image_search/
  end
end.flatten.reduce({}) do |memo, line|
  query = URI.decode(line.match(/GET \"\/api\/image_search.*[?&]query=([^?&\"]*)[&?\"]/)[1])
  memo[query] = (memo[query] || 0) + 1
  memo
end

puts "Data generated #{data.count} keys"

csv = CSV.generate("", :headers => [:query, :count]) do |csv|
  data.each do |query, count|
    csv << [query, count]
  end
end

puts "CSV generated, writing file"

File.open("result.csv", "wb") do |f|
  f.write(csv)
end