Restart Rails server during deploy

config/deploy.rb

@@ -50,3 +50,5 @@ append :linked_dirs,
 # Uncomment the following to require manually verifying the host key
 # before first deploy.
 # set :ssh_options, verify_host_key: :secure
+
+after 'deploy:published', 'rails:restart'

config/puma/production.rb

@@ -32,4 +32,4 @@ threads threads_count, threads_count
 bind "unix://#{Rails.root.join('tmp', 'sockets', 'puma.sock')}"
 
 # Allow puma to be restarted by `rails restart` command.
-# plugin :tmp_restart
+plugin :tmp_restart

lib/capistrano/tasks/rails.rake

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+namespace :load do
+  task :defaults do
+    set :rails_restart_roles, %i[web]
+  end
+end
+
+namespace :rails do
+  desc 'Restart app by touching tmp/restart.txt'
+  task :restart do
+    on roles(fetch(:rails_restart_roles)) do |_host|
+      within release_path do
+        execute :bundle, :exec, :rails, :restart
+      end
+    end
+  end
+end