shrine (rubygems): Shrine is a toolkit for file attachments in Ruby applications. It supports uploading, downloading, processing and deleting IO objects, backed by various storage engines. It uses efficient streaming for low memory usage.  Shrine comes with a high-level interface for attaching uploaded files to database records, saving their location and metadata to a database column, and tying them to record's lifecycle. It natively supports background jobs and direct uploads for fully asynchronous user experience. 
Keywords: attachment|background-jobs|direct-upload|file-upload|filesystem|metadata|orm|rack|ruby|s3|storage