Script that helps to download images from old server using url stored in database and old :host_url:

image_loader.rb

class HomeController
  def download
    require 'open-uri'
    require 'fileutils'

    icons = Icon.all
    posts = Post.all
    snapshots = Snapshot.all

    icons.each do |icon|
      create_image icon.picture.url
      create_image icon.picture.url(:picture)
      create_image icon.picture.url(:picture2x)
    end

    posts.each do |post|
      create_image post.teaser.url
      create_image post.teaser.url(:thumbnail)
      create_image post.teaser.url(:picture)
      create_image post.teaser.url(:picture2x)
    end

    snapshots.each do |snapshot|
      create_image snapshot.snap.url
      create_image snapshot.snap.url(:thumbnail)
      create_image snapshot.snap.url(:thumbnail_2x)
    end
  end

  def create_image(url)
    remote_host = ':host_url:'

    url.gsub!(/\?.*/, "")

    name = File.basename(url)
    _url = url.gsub("/#{name}", "")
    path = ":local_public_folder:#{_url}"

    logger.debug "#{remote_host}#{url}"

    FileUtils.mkdir_p(path) unless File.exists?(path)

    logger.debug "#{path}/#{name}"

    open("#{path}/#{name}", 'wb') do |file|
      file << open("#{remote_host}#{url}").read
    end
  end
end