s3_directory_service.rb

# frozen_string_literal: true

# This file lives in lib/active_storage/service/s3_directory_service.rb.

require 'aws-sdk-s3'
require 'active_storage/service/s3_service'
require 'active_support/core_ext/numeric/bytes'

module ActiveStorage
  class Service
    class S3DirectoryService < S3Service
      def proxy_url(url)
        return url unless ENV['ATTACHMENT_HOST']

        URI.join(ENV['ATTACHMENT_HOST'], URI(url).path).to_s
      end

      def url(key, **)
        instrument :url, key: key do |payload|
          payload[:url] = proxy_url object_for(key).public_url
        end
      end
    end
  end
end

storage.yml

# This file lives in config/storage.yml.

test:
  service: Disk
  root: <%= Rails.root.join("tmp/storage") %>

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

amazon:
  service: S3Directory
  access_key_id: <%= ENV['AWS_ACCESS_KEY_ID'] %>
  secret_access_key: <%= ENV['AWS_SECRET_ACCESS_KEY'] %>
  region: <%= ENV['AWS_S3_REGION'] %>
  bucket: <%= ENV['AWS_BUCKET'] %>
  upload:
    cache_control: 'public, max-age=31536000'