Add S3_FORCE_SINGLE_REQUEST env var to work around S3 compatibility issues (#16866)

Fixes #16822

config/application.rb

@@ -27,6 +27,7 @@ require_relative '../lib/sanitize_ext/sanitize_config'
 require_relative '../lib/redis/namespace_extensions'
 require_relative '../lib/paperclip/url_generator_extensions'
 require_relative '../lib/paperclip/attachment_extensions'
+require_relative '../lib/paperclip/storage_extensions'
 require_relative '../lib/paperclip/lazy_thumbnail'
 require_relative '../lib/paperclip/gif_transcoder'
 require_relative '../lib/paperclip/transcoder'

lib/paperclip/storage_extensions.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+# Some S3-compatible providers might not actually be compatible with some APIs
+# used by kt-paperclip, see https://github.com/mastodon/mastodon/issues/16822
+if ENV['S3_ENABLED'] == 'true' && ENV['S3_FORCE_SINGLE_REQUEST'] == 'true'
+  module Paperclip
+    module Storage
+      module S3Extensions
+        def copy_to_local_file(style, local_dest_path)
+          log("copying #{path(style)} to local file #{local_dest_path}")
+          s3_object(style).download_file(local_dest_path, { mode: 'single_request' })
+        rescue Aws::Errors::ServiceError => e
+          warn("#{e} - cannot copy #{path(style)} to local file #{local_dest_path}")
+          false
+        end
+      end
+    end
+  end
+
+  Paperclip::Storage::S3.prepend(Paperclip::Storage::S3Extensions)
+end