image_url gives different result when run from controller?

问题

The problem

This code: image_url('my_image.png') generates this url from within the view:

http://localhost:3000/assets/my_image-d229e5de55e4f8589c78e2419221fa3ae4f9d4026f.png

But when the same code is run from the controller, it generates this:

http://localhost:3000/images/my_image.png

Only the first url actually works. How can I generate the correct url (the one containing the fingerprint) from the controller?

What I tried

I found a way to make it work locally, by generating the digest manually.

This method generates the correct url

def make_image_url_with_fingerprint(image_path)
  request.base_url + "/assets/" + Rails.application.assets.find_asset(image_path).digest_path 
end

And to use it:

make_image_url_with_fingerprint('my_image.png')
=> http://localhost:3000/assets/my_image-d229e5de55e4f8589c78e2419221fa3ae4f9d4026f.png

However, this doesn't work in production, probably because the assets are already compiled and therefore there's nothing at Rails.application.assets.find_asset(image_path)

Other notes:

• Similar question here: rails 4 not using digests in asset filenames, but only in production

• I couldn't solve this in production after 9 hours. So I created a new S3 bucket, copied the image there, and reference it directly from it's S3 url. This is annoying since it skips all of the rails conventions (assets in one place, precompilation etc), but I needed a quick fix and can figure out a better solution in good time.

来源：https://stackoverflow.com/questions/65990841/image-url-gives-different-result-when-run-from-controller