Active Storage (Disk) - Access uploads across subdomains

Question

I have a SaaS app built on subdomains per tenant. Following a Rails migration, I am trying to replace CarrierWave with ActiveStorage.

The application is structured like this:

• www.givingfire.test - marketing site
• admin.givingfire.test - admin portal
• tenant-1.givingfire.test - tenant 1

After migrating the images from CarrierWave to ActiveStorage I noticed that the images would give a 404. Then I uploaded an image in the admin.givingfire.com subdomain. It was accessible in the admin subdomain but not elsewhere.

• http://www.givingfire.test/rails/active_storage/disk/ey.../ipad-app.jpeg [404]
• http://admin.givingfire.test/rails/active_storage/disk/ey.../ipad-app.jpeg Ok

Ideally we would put it in a S3 bucket and use CloudFront as a CDN but its not an option here and at least for a start we will be using disk storage.

I looked in ActiveStorage tables in the DB and I can't see any config pointing towards a subdomain. I wonder if it is included in the ActiveStorage::Blob#checksum.

class Upload < ApplicationRecord
  has_one_attached :file
end

// It is a Trailblazer::Cell
.col-sm-3
  .blog-details
    - featured_image do |image|
      .blog-image.mb-10
        = link_to view_path do
          = image_tag(\
            image.file.representation(resize_to_fill: [266, 156]).processed.url,
            class: 'img-responsive',
          )

# config/environmentes/development.rb

require 'active_support/core_ext/integer/time'

Rails.application.configure do
  # ...
  config.hosts << /givingfire\.test/
  config.hosts << /[a-z0-9]+\.givingfire\.test/
end

# config/storage.yml
local:
  service: Disk
  root: <%= Rails.root.join("storage") %>

Anyone know why and how I can solve this problem?