make active storage work only when set up to locally store files

app/controllers/local_files_controller.rb

@@ -0,0 +1,16 @@
+class LocalFilesController < ApplicationController
+  skip_forgery_protection
+
+  def show
+    blob = ActiveStorage::Blob.find_by(key: params[:key])
+
+    if blob.present? && blob.service.is_a?(ActiveStorage::Service::DiskService)
+      send_file blob.service.path_for(blob.key),
+        type: blob.content_type,               # Set correct MIME type
+        disposition: :inline,                  # Show in browser
+        filename: blob.filename.to_s           # Ensure correct filename
+    else
+      head :not_found
+    end
+  end
+end

config/initializers/active_storage_blob_patch.rb

@@ -0,0 +1,44 @@
+# ensure logger is available
+logger = Rails.logger
+
+if ENV["SKIP_ACTIVE_STORAGE_PATCH"] == "true"
+  logger.info "SKIP_ACTIVE_STORAGE_PATCH is set. Skip loading Active Storage Patch ..."
+else
+  Rails.application.config.to_prepare do
+    logger.info "Loading Active Storage Blob Patch ..."
+
+    class ActiveStorage::Blob < ActiveStorage::Record
+      # Ensure variants are deleted only if variants tracking is disabled
+      # This is needed because ActiveStorage::PurgeJob fails if variants are tracked
+      # but also fails if variants are not tracked. The latter also keeps files in
+      # the variants folder which are basically stale.
+      # see https://github.com/rails/rails/issues/50583
+      def delete
+        service.delete(key)
+        
+        # Never delete variants
+        # I had to edit the github snippet to make it work
+        # service.delete_prefixed("variants/#{key}/") if image? && !ActiveStorage.track_variants
+      end
+
+      # Override url method
+      # This is needed because ActiveStorage::Blob#url method does not work with local disk service
+      # Use LocalFilesController to serve local files if active storage service is local disk
+      # Otherwise use the default ActiveStorage::Blob#url method
+      def url(**options)
+        if service.is_a?(ActiveStorage::Service::DiskService)
+          Rails.application.routes.url_helpers.local_file_url(key: key, host: Rails.application.base_url)
+        else
+          service.url(
+            key,
+            expires_in: 5.minutes,
+            disposition: :inline,
+            filename: self.filename,
+            content_type: self.content_type,
+            **options
+          )
+        end
+      end
+    end
+  end
+end

config/initializers/active_storage_blob_purge_patch.rb

@@ -1,27 +0,0 @@
-# https://github.com/rails/rails/issues/50583#issuecomment-1920061327
-
-# ensure logger is available
-logger = Rails.logger
-
-if ENV["SKIP_ACTIVE_STORAGE_PATCH"] == "true"
-  logger.info "SKIP_ACTIVE_STORAGE_PATCH is set. Skip loading Active Storage Patch ..."
-else
-  # Ensure variants are deleted only if variants tracking is disabled
-  # This is needed because ActiveStorage::PurgeJob fails if variants are tracked
-  # but also fails if variants are not tracked. The latter also keeps files in
-  # the variants folder which are basically stale.
-  # see https://github.com/rails/rails/issues/50583
-  Rails.application.config.to_prepare do
-    logger.info "Loading Active Storage Blob Purge Patch ..."
-
-    class ActiveStorage::Blob < ActiveStorage::Record
-      def delete
-        service.delete(key)
-        
-        # Never delete variants
-        # I had to edit the github snippet to make it work
-        # service.delete_prefixed("variants/#{key}/") if image? && !ActiveStorage.track_variants
-      end
-    end
-  end
-end

config/routes.rb

@@ -1,6 +1,9 @@
 Rails.application.routes.draw do
   if !Rails.application.multi_tenancy?
     mount Rswag::Api::Engine => '/api-docs'
+    
+    # in case active storage backend is local disk
+    get "/local_files/:key", to: "local_files#show", as: :local_file
   end
 
   if Rails.application.multi_tenancy?