Revert to using Paperclip's filesystem storage, and fix dangling records in remove_remote (#8339)

* Fix uncaching worker

* Revert to using Paperclip's filesystem backend instead of fog-local

fog-local has lots of concurrency issues, causing failure to delete files,
dangling file records, and spurious errors UncacheMediaWorker

Gemfile

@@ -16,7 +16,6 @@ gem 'dotenv-rails', '~> 2.2', '< 2.3'
 
 gem 'aws-sdk-s3', '~> 1.9', require: false
 gem 'fog-core', '~> 1.45'
-gem 'fog-local', '~> 0.5', require: false
 gem 'fog-openstack', '~> 0.1', require: false
 gem 'paperclip', '~> 6.0'
 gem 'paperclip-av-transcoder', '~> 0.6'

Gemfile.lock

@@ -220,8 +220,6 @@ GEM
     fog-json (1.0.2)
       fog-core (~> 1.0)
       multi_json (~> 1.10)
-    fog-local (0.5.0)
-      fog-core (>= 1.27, < 3.0)
     fog-openstack (0.1.25)
       fog-core (~> 1.40)
       fog-json (>= 1.0)
@@ -679,7 +677,6 @@ DEPENDENCIES
   fast_blank (~> 1.0)
   fastimage
   fog-core (~> 1.45)
-  fog-local (~> 0.5)
   fog-openstack (~> 0.1)
   fuubar (~> 2.2)
   goldfinger (~> 2.1)

app/workers/maintenance/uncache_media_worker.rb

@@ -8,7 +8,7 @@ class Maintenance::UncacheMediaWorker
   def perform(media_attachment_id)
     media = MediaAttachment.find(media_attachment_id)
 
-    return unless media.file.exists?
+    return if media.file.blank?
 
     media.file.destroy
     media.save

config/initializers/paperclip.rb

@@ -74,14 +74,10 @@ elsif ENV['SWIFT_ENABLED'] == 'true'
     fog_public: true
   )
 else
-  require 'fog/local'
-
   Paperclip::Attachment.default_options.merge!(
-    fog_credentials: {
-      provider: 'Local',
-      local_root: ENV.fetch('PAPERCLIP_ROOT_PATH') { Rails.root.join('public', 'system') },
-    },
-    fog_directory: '',
-    fog_host: ENV.fetch('PAPERCLIP_ROOT_URL') { '/system' }
+    storage: :filesystem,
+    use_timestamp: true,
+    path: (ENV['PAPERCLIP_ROOT_PATH'] || ':rails_root/public/system') + '/:class/:attachment/:id_partition/:style/:filename',
+    url: (ENV['PAPERCLIP_ROOT_URL'] || '/system') + '/:class/:attachment/:id_partition/:style/:filename',
   )
 end