Cookbook [postgresql] (https://supermarket.chef.io/cookbooks/postgresql) contains a recipe called server_conf.rb
whose content is:
change_notify = node['postgresql']['server']['config_change_notify']
template "#{node['postgresql']['dir']}/postgresql.conf" do
source "postgresql.conf.erb"
owner "postgres"
group "postgres"
mode 0600
notifies change_notify, 'service[postgresql]', :immediately