Class: Jobs::PullHotlinkedImages

Inherits:
Base
  • Object
show all
Defined in:
app/jobs/regular/pull_hotlinked_images.rb

Direct Known Subclasses

PullUserProfileHotlinkedImages

Defined Under Namespace

Classes: ImageBrokenError, ImageTooLargeError, UploadCreateError

Instance Method Summary collapse

Methods inherited from Base

acquire_cluster_concurrency_lock!, clear_cluster_concurrency_lock!, cluster_concurrency, cluster_concurrency_redis_key, delayed_perform, #error_context, get_cluster_concurrency, #last_db_duration, #perform, #perform_immediately

Instance Method Details

#attempt_download(src, user_id) ⇒ Object

Raises:



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# File 'app/jobs/regular/pull_hotlinked_images.rb', line 129

def attempt_download(src, user_id)
  # secure-uploads endpoint prevents anonymous downloads, so we
  # need the presigned S3 URL here
  src = Upload.signed_url_from_secure_uploads_url(src) if Upload.secure_uploads_url?(src)

  hotlinked = download(src)
  raise ImageBrokenError if !hotlinked
  if File.size(hotlinked.path) > SiteSetting.max_image_size_kb.kilobytes
    raise ImageTooLargeError
  end

  filename = File.basename(URI.parse(src).path)
  filename << File.extname(hotlinked.path) unless filename["."]
  upload = UploadCreator.new(hotlinked, filename, origin: src).create_for(user_id)

  if upload.persisted?
    upload
  else
    log(
      :info,
      "Failed to persist downloaded hotlinked image for post: #{@post_id}: #{src} - #{upload.errors.full_messages.join("\n")}",
    )
    raise UploadCreateError
  end
end

#download(src) ⇒ Object



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# File 'app/jobs/regular/pull_hotlinked_images.rb', line 87

def download(src)
  downloaded = nil

  begin
    retries ||= 3

    if SiteSetting.verbose_upload_logging
      Rails.logger.warn("Verbose Upload Logging: Downloading hotlinked image from #{src}")
    end

    downloaded =
      FileHelper.download(
        src,
        max_file_size: SiteSetting.max_image_size_kb.kilobytes,
        retain_on_max_file_size_exceeded: true,
        tmp_file_name: "discourse-hotlinked",
        follow_redirect: true,
        read_timeout: 15,
      )
  rescue => e
    if SiteSetting.verbose_upload_logging
      Rails.logger.warn("Verbose Upload Logging: Error '#{e.message}' while downloading #{src}")
    end

    if (retries -= 1) > 0 && !Rails.env.test?
      sleep 1
      retry
    end
  end

  downloaded
end

#execute(args) ⇒ Object



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# File 'app/jobs/regular/pull_hotlinked_images.rb', line 7

def execute(args)
  disable_if_low_on_disk_space

  @post_id = args[:post_id]
  raise Discourse::InvalidParameters.new(:post_id) if @post_id.blank?

  # in test we have no choice cause we don't want to cause a deadlock
  if Jobs.run_immediately?
    pull_hotlinked_images
  else
    DistributedMutex.synchronize("pull_hotlinked_images_#{@post_id}", validity: 2.minutes) do
      pull_hotlinked_images
    end
  end
end

#extract_images_from(html) ⇒ Object



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# File 'app/jobs/regular/pull_hotlinked_images.rb', line 155

def extract_images_from(html)
  doc = Nokogiri::HTML5.fragment(html)

  doc.css("img[src], [#{PrettyText::BLOCKED_HOTLINKED_SRC_ATTR}], a.lightbox[href]") -
    doc.css("img.avatar") - doc.css(".lightbox img[src]")
end

#log(log_level, message) ⇒ Object



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# File 'app/jobs/regular/pull_hotlinked_images.rb', line 204

def log(log_level, message)
  Rails.logger.public_send(
    log_level,
    "#{RailsMultisite::ConnectionManagement.current_db}: #{message}",
  )
end

#pull_hotlinked_imagesObject



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# File 'app/jobs/regular/pull_hotlinked_images.rb', line 23

def pull_hotlinked_images
  post = Post.find_by(id: @post_id)
  return if post.nil? || post.topic.nil?

  hotlinked_map = post.post_hotlinked_media.map { |r| [r.url, r] }.to_h

  changed_hotlink_records = false

  extract_images_from(post.cooked).each do |node|
    download_src =
      original_src = node["src"] || node[PrettyText::BLOCKED_HOTLINKED_SRC_ATTR] || node["href"]
    download_src = replace_encoded_src(download_src)
    download_src =
      "#{SiteSetting.force_https ? "https" : "http"}:#{original_src}" if original_src.start_with?(
      "//",
    )
    normalized_src = normalize_src(download_src)

    next if !should_download_image?(download_src, post)

    hotlink_record = hotlinked_map[normalized_src]

    if hotlink_record.nil?
      hotlinked_map[normalized_src] = hotlink_record =
        PostHotlinkedMedia.new(post: post, url: normalized_src)
      begin
        hotlink_record.upload = attempt_download(download_src, post.user_id)
        hotlink_record.status = :downloaded
      rescue ImageTooLargeError
        hotlink_record.status = :too_large
      rescue ImageBrokenError
        hotlink_record.status = :download_failed
      rescue UploadCreateError
        hotlink_record.status = :upload_create_failed
      end
    end

    if hotlink_record.changed?
      changed_hotlink_records = true
      hotlink_record.save!
    end
  rescue => e
    raise e if Rails.env.test?
    log(
      :error,
      "Failed to pull hotlinked image (#{download_src}) post: #{@post_id}\n" + e.message +
        "\n" + e.backtrace.join("\n"),
    )
  end

  if changed_hotlink_records
    post.trigger_post_process(
      bypass_bump: true,
      skip_pull_hotlinked_images: true, # Avoid an infinite loop of job scheduling
    )
  end

  if hotlinked_map.size > 0
    Jobs.cancel_scheduled_job(:update_hotlinked_raw, post_id: post.id)
    update_raw_delay = SiteSetting.editing_grace_period + 1
    Jobs.enqueue_in(update_raw_delay, :update_hotlinked_raw, post_id: post.id)
  end
end

#should_download_image?(src, post = nil) ⇒ Boolean

Returns:

  • (Boolean)


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# File 'app/jobs/regular/pull_hotlinked_images.rb', line 162

def should_download_image?(src, post = nil)
  # make sure we actually have a url
  return false if src.blank?

  local_bases =
    [Discourse.base_url, Discourse.asset_host, SiteSetting.external_emoji_url.presence].compact
      .map { |s| normalize_src(s) }

  if Discourse.store.has_been_uploaded?(src) || normalize_src(src).start_with?(*local_bases) ||
       src =~ %r{\A/[^/]}i
    return false if !(src =~ %r{/uploads/} || Upload.secure_uploads_url?(src))

    # Someone could hotlink a file from a different site on the same CDN,
    # so check whether we have it in this database
    #
    # if the upload already exists and is attached to a different post,
    # or the original_sha1 is missing meaning it was created before secure
    # media was enabled, then we definitely want to redownload again otherwise
    # we end up reusing existing uploads which may be linked to many posts
    # already.
    upload = Upload.consider_for_reuse(Upload.get_from_url(src), post)

    return !upload.present?
  end

  # Don't download non-local images unless site setting enabled
  return false unless SiteSetting.download_remote_images_to_local?

  # parse the src
  begin
    uri = URI.parse(src)
  rescue URI::Error
    return false
  end

  hostname = uri.hostname
  return false unless hostname

  # check the domains blocklist
  SiteSetting.should_download_images?(src)
end