Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
	app/views/layouts/application.html.haml

Edited:
        app/helpers/application_helper.rb
        app/views/admin/domain_blocks/new.html.haml

Conflict wasn't really one, just two changes too close to one another.
Edition was to adapt the class names for themes to class names for
skins and flavours.

Also edited app/views/admin/domain_blocks/new.html.haml to strip the
duplicate admin pack inclusion thing.

lib/mastodon/media_cli.rb

@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require_relative '../../config/boot'
+require_relative '../../config/environment'
+
+# rubocop:disable Rails/Output
+
+module Mastodon
+  class MediaCLI < Thor
+    option :days, type: :numeric, default: 7
+    option :background, type: :boolean, default: false
+    desc 'remove', 'remove remote media files'
+    long_desc <<-DESC
+      Removes locally cached copies of media attachments from other servers.
+
+      The --days option specifies how old media attachments have to be before
+      they are removed. It defaults to 7 days.
+
+      With the --background option, instead of deleting the files sequentially,
+      they will be queued into Sidekiq and the command will exit as soon as
+      possible. In Sidekiq they will be processed with higher concurrency, but
+      it may impact other operations of the Mastodon server, and it may overload
+      the underlying file storage.
+    DESC
+    def remove
+      time_ago = options[:days].days.ago
+      queued   = 0
+
+      MediaAttachment.where.not(remote_url: '').where.not(file_file_name: nil).where('created_at < ?', time_ago).select(:id).reorder(nil).find_in_batches do |media_attachments|
+        if options[:background]
+          queued += media_attachments.size
+          Maintenance::UncacheMediaWorker.push_bulk(media_attachments.map(&:id))
+        else
+          media_attachments.each do |m|
+            Maintenance::UncacheMediaWorker.new.perform(m)
+            print '.'
+          end
+        end
+      end
+
+      puts
+      puts "Scheduled the deletion of #{queued} media attachments" if options[:background]
+    end
+  end
+end
+
+# rubocop:enable Rails/Output