Fix-up variants controller

app/controllers/active_storage/direct_uploads_controller.rb

+class ActiveStorage::DirectUploadsController < ActionController::Base
+  def create
+    blob = ActiveStorage::Blob.create_before_direct_upload!(blob_args)
+    render json: { url: blob.url_for_direct_upload, sgid: blob.to_sgid.to_param }
+  end
+
+  private
+    def blob_args
+      params.require(:blob).permit(:filename, :byte_size, :checksum, :content_type, :metadata).to_h.symbolize_keys
+    end
+end

lib/active_storage/controllers/variants_controller.rb

-require "action_controller"
-require "active_storage/blob"
-
-class ActiveStorage::Controllers::VariantsController < ActionController::Base
-  def show
-    if blob_key = decode_verified_key
-      variant = ActiveStorage::Variant.find_or_create_by(blob_key: blob_key, variation_key: params[:variation_key])
-      redirect_to variant.url
-    else
-      head :not_found
-    end
-  end
-
-  private
-    def decode_verified_key
-      ActiveStorage::VerifiedKeyWithExpiration.decode(params[:encoded_key])
-    end
-
-    def disposition_param
-      params[:disposition].presence_in(%w( inline attachment )) || 'inline'
-    end
-end