discourse/config/initializers/100-watch_for_restart.rb

45 lines
1.4 KiB
Ruby

# frozen_string_literal: true
# this is a trivial graceful restart on touch of tmp/restart.
#
# It simply drains all the requests (waits up to 4 seconds) and issues a HUP
# if you need a more sophisticated cycling restart for multiple thins it will need to be written
#
# This works fine for Discourse.org cause we host our app accross multiple machines, if you hosting
# on a single machine you have a trickier problem at hand as you need to cycle the processes in order
#
# VIM users rejoice, if you add this to your .vimrc CTRL-a will restart puma:
# nmap <C-a> <Esc>:!touch tmp/restart<CR><CR>
Thread.new do
file = "#{Rails.root}/tmp/restart"
old_time = File.ctime(file).to_i if File.exists? file
wait_seconds = 4
if Rails.env.development? && $PROGRAM_NAME =~ /puma/
require 'listen'
time = nil
begin
listener = Listen.to("#{Rails.root}/tmp", only: /restart/) do
time = File.ctime(file).to_i if File.exists? file
if old_time != time
Rails.logger.info "attempting to reload #{$$} #{$PROGRAM_NAME} in #{wait_seconds} seconds"
$shutdown = true # rubocop:disable Style/GlobalVars
sleep wait_seconds
Rails.logger.info "restarting #{$$}"
Process.kill("USR2", $$)
end
end
listener.start
sleep
rescue => e
puts "Failed to watch for restart, this probably means the old postgres directory is in tmp, remove it #{e}"
end
end
end