upload images to carrierwave with a local server.

thin_upload_carrier.rb

seed_data = [
  {model_name: "somename", image:"my_image.jpg"},
  #...
]

thin_server = Thread.start do
  Thin::Server.start('0.0.0.0', 4567) do
    run Rack::Directory.new( File.join(Dir.pwd,"seed-images") )
  end
end

seed_data.each do |seed|
  model = Model.find_by_name(seed[:model_name])
  model.remote_image_url="http://localhost:4567/#{model[:image]}"
  model.save
end

thin_server.kill