I have images that are generated by users and written to
config.serve_static_files = true
config.assets.compile = true
Rails.application.config.assets.paths << Rails.root.join('public', 'designer', 'designer_output')
public folder is used as the web root for the rails server.
You need to drop
public in the path or URL:
<!-- file is at /public/foo/bar.png --!> <img src="/foo/bar.png" />