Sergey S. erdbehrmund

Zero downtime deploys with unicorn + nginx + runit + rvm + chef

Below are the actual files we use in one of our latest production applications at Agora Games to achieve zero downtime deploys with unicorn. You've probably already read the GitHub blog post on Unicorn and would like to try zero downtime deploys for your application. I hope these files and notes help. I am happy to update these files or these notes if there are comments/questions. YMMV (of course).

Other application notes:

Our application uses MongoDB, so we don't have database migrations to worry about as with MySQL or postgresql. That does not mean that we won't have to worry about issues with the database with indexes being built in MongoDB or what have you.
We use capistrano for deployment.

Salient points for each file:

	#!/bin/bash
	# WAN Load-Balancing Symmetry workaround
	# steven.kath@vyatta.com 2012-09-22
	# See https://bugzilla.vyatta.com/show_bug.cgi?id=6245 for background.

	if [[ $UID != 0 ]]; then
	echo -e "This script must be run with root permissions. Try:\n sudo $0"
	exit
	fi

	# Your NAS Synology device suddenly lost connection to your Windows Domain Controller, and or intermittent AD connectivity issues.
	# Symptoms include but not limited to:
	# - Failing to rejoin after removing the account on the Domain.
	# - Failing to rejoin without any changes
	# - Join attempt results in = "Failed to join the Windows domain. Please check your domain and firewall settings and try again"
	# - Synology is joined, but attempting to connect from domain clients results in "There are no logon servers available to service the logon request"
	# - This problem happens intermittently, sometimes rebooting the Synology device allows you to rejoin (Not a solution).
	# - Sometimes rebooting both Synology device and Domain Controller allows you to rejoin (Not a solution).

	# 1st.) OPTIONAL Remove the AD Synology device from Avtice Directory Users/Computers.

	#!/bin/bash

	### BEGIN INIT INFO
	# Provides: ahn
	# Required-Start: ahn daemon
	# Required-Stop: ahn daemon
	# chkconfig: 2345 91 60
	# Default-Start: 2 3 4 5
	# Default-Stop: 0 1 6
	# Short-Description: Adhearsion daemon

	# with my git configuration the spree repo was giving me issues with line endings
	# this fixed the issue for me: marking a file as binary causes git to ignore it completely

	core/vendor/assets/javascripts/jquery.alerts/jquery.alerts.css.erb binary
	core/vendor/assets/javascripts/jquery.alerts/jquery.alerts.js binary
	core/vendor/assets/javascripts/jquery.jstree/themes/apple/style.css binary
	sample/db/sample/spree/line_items.yml binary
	sample/db/sample/spree/products.yml binary

	update-rc.d logstash-shipper defaults
	update-rc.d logstash-reader defaults

	worker: QUEUE=* bundle exec rake environment resque:work
	scheduler: bundle exec rake environment resque:scheduler