discourse/lib/tasks/uploads.rake

require "digest/sha1"

task "uploads:backfill_shas" => :environment do
  RailsMultisite::ConnectionManagement.each_connection do |db|
    puts "Backfilling #{db}"
    Upload.select([:id, :sha, :url]).find_each do |u|
      if u.sha.nil?
        putc "."
        path = "#{Rails.root}/public/#{u.url}"
        sha = Digest::SHA1.file(path).hexdigest
        begin
          Upload.update_all ["sha = ?", sha], ["id = ?", u.id]
        rescue ActiveRecord::RecordNotUnique
          # not a big deal if we've got a few duplicates
        end
      end
    end
  end
  puts "done"
end

task "uploads:migrate_from_s3" => :environment do
  require 'file_store/local_store'
  require 'file_helper'

  local_store = FileStore::LocalStore.new
  max_file_size = [SiteSetting.max_image_size_kb, SiteSetting.max_attachment_size_kb].max.kilobytes

  puts "Migrating uploads from S3 to local storage"
  puts

  Upload.order(:id).find_each do |upload|

    # remove invalid uploads
    if upload.url.blank?
      upload.destroy!
      next
    end

    # no need to download an upload twice
    if local_store.has_been_uploaded?(upload.url)
      putc '.'
      next
    end

    # try to download the upload
    begin
      # keep track of the previous url
      previous_url = upload.url
      # fix the name of pasted images
      upload.original_filename = "blob.png" if upload.original_filename == "blob"
      # download the file (in a temp file)
      temp_file = FileHelper.download("http:" + previous_url, max_file_size, "from_s3")
      # store the file locally
      upload.url = local_store.store_upload(temp_file, upload)
      # save the new url
      if upload.save
        # update & rebake the posts (if any)
        Post.where("raw ILIKE ?", "%#{previous_url}%").find_each do |post|
          post.raw.gsub!(previous_url, upload.url)
          post.rebake!
        end

        putc '#'
      else
        putc 'X'
      end

      # close the temp_file
      temp_file.close! if temp_file.respond_to? :close!
    rescue
      putc 'X'
    end

  end

  puts

end