require_dependency 'url_helper' require_dependency 'file_helper' module Jobs class PullHotlinkedImages < Jobs::Base include UrlHelper def initialize # maximum size of the file in bytes @max_size = SiteSetting.max_image_size_kb.kilobytes end def execute(args) return unless SiteSetting.download_remote_images_to_local? post_id = args[:post_id] raise Discourse::InvalidParameters.new(:post_id) unless post_id.present? post = Post.find_by(id: post_id) return unless post.present? raw = post.raw.dup start_raw = raw.dup downloaded_urls = {} extract_images_from(post.cooked).each do |image| src = image['src'] src = "http:" + src if src.start_with?("//") if is_valid_image_url(src) hotlinked = nil begin # have we already downloaded that file? unless downloaded_urls.include?(src) begin hotlinked = FileHelper.download(src, @max_size, "discourse-hotlinked") rescue Discourse::InvalidParameters end if hotlinked if hotlinked.size <= @max_size filename = File.basename(URI.parse(src).path) upload = Upload.create_for(post.user_id, hotlinked, filename, hotlinked.size, { origin: src }) downloaded_urls[src] = upload.url else Rails.logger.error("Failed to pull hotlinked image: #{src} - Image is bigger than #{@max_size}") end else Rails.logger.error("There was an error while downloading '#{src}' locally.") end end # have we successfully downloaded that file? if downloaded_urls[src].present? url = downloaded_urls[src] escaped_src = Regexp.escape(src) # there are 6 ways to insert an image in a post # HTML tag - raw.gsub!(/src=["']#{escaped_src}["']/i, "src='#{url}'") # BBCode tag - [img]http://...[/img] raw.gsub!(/\[img\]#{escaped_src}\[\/img\]/i, "[img]#{url}[/img]") # Markdown linked image - [![alt](http://...)](http://...) raw.gsub!(/\[!\[([^\]]*)\]\(#{escaped_src}\)\]/) { "[#{$1}]" } # Markdown inline - ![alt](http://...) raw.gsub!(/!\[([^\]]*)\]\(#{escaped_src}\)/) { "![#{$1}](#{url})" } # Markdown reference - [x]: http:// raw.gsub!(/\[(\d+)\]: #{escaped_src}/) { "[#{$1}]: #{url}" } # Direct link raw.gsub!(src, "") end rescue => e Rails.logger.error("Failed to pull hotlinked image: #{src}\n" + e.message + "\n" + e.backtrace.join("\n")) ensure # close & delete the temp file hotlinked && hotlinked.close! end end end post.reload if start_raw != post.raw # post was edited - start over (after 10 minutes) backoff = args.fetch(:backoff, 1) + 1 delay = SiteSetting.ninja_edit_window * args[:backoff] Jobs.enqueue_in(delay.seconds.to_i, :pull_hotlinked_images, args.merge!(backoff: backoff)) elsif raw != post.raw changes = { raw: raw, edit_reason: I18n.t("upload.edit_reason") } # we never want that job to bump the topic options = { bypass_bump: true } post.revise(Discourse.system_user, changes, options) end end def extract_images_from(html) doc = Nokogiri::HTML::fragment(html) doc.css("img[src]") - doc.css(".onebox-result img") - doc.css("img.avatar") end def is_valid_image_url(src) # make sure we actually have a url return false unless src.present? # we don't want to pull uploaded images return false if Discourse.store.has_been_uploaded?(src) # we don't want to pull relative images return false if src =~ /\A\/[^\/]/i # parse the src begin uri = URI.parse(src) rescue URI::InvalidURIError return false end # we don't want to pull images hosted on the CDN (if we use one) return false if Discourse.asset_host.present? && URI.parse(Discourse.asset_host).hostname == uri.hostname return false if SiteSetting.s3_cdn_url.present? && URI.parse(SiteSetting.s3_cdn_url).hostname == uri.hostname # we don't want to pull images hosted on the main domain return false if URI.parse(Discourse.base_url_no_prefix).hostname == uri.hostname # check the domains blacklist SiteSetting.should_download_images?(src) end end end