John Albietz inthecloud247

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:

	sudo apt-get update
	sudo apt-get install -y libssl1.0.0 openssl

	# Confirm Build Date is at least Aril 7th 2014
	openssl version -a

	# Restart all services listed by this command:
	sudo lsof -n \| grep ssl \| grep DEL

	FROM google/cloud-sdk
	RUN apt-get update && apt-get install -y --no-install-recommends curl sshpass netcat-traditional
	RUN curl https://get.docker.io/builds/Linux/x86_64/docker-latest -o /bin/docker && chmod +x /bin/docker
	RUN curl http://stedolan.github.io/jq/download/linux64/jq -o /bin/jq && chmod +x /bin/jq
	ADD gce2docker-fork.sh /
	EXPOSE 44243
	ENV DOCKER_HOST :44243
	ENTRYPOINT ["/gce2docker-fork.sh"]

	#!/bin/bash
	#
	# This file is managed by Chef, using the <%= node.name %> cookbook.
	# Editing this file by hand is highly discouraged!
	#

	# Copyright (c) 2014 Jean Mertz <[email protected]>
	#
	# Permission is hereby granted, free of charge, to any person obtaining a copy
	# of this software and associated documentation files (the "Software"), to deal

	#!/bin/sh
	echo Install all AppStore Apps at first!
	# no solution to automate AppStore installs
	read -p "Press any key to continue... " -n1 -s
	echo '\n'

	echo Install and Set San Francisco as System Font
	ruby -e "$(curl -fsSL https://raw.github.com/wellsriley/YosemiteSanFranciscoFont/master/install)"
	echo Install Homebrew, Postgres, wget and cask
	ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"

	# Example config to run single processes in docker, managed by
	# supervisord.
	#
	# This probably isn't the "right" way to do it, I haven't
	# found a better solution online though. Keep in mind, supervisor
	# wants non-daemonized processes, which is why we run them with the
	# -i flag. If you are running something like mysqld, be sure to use
	# the pidproxy application as described here:
	# http://supervisord.org/subprocess.html?highlight=pidproxy#pidproxy-program
	#

	# Setup the application's runit directory
	/etc/sv/application:
	file.directory:
	- mode: 0755
	- user: someuser
	- group: someuser
	- recurse:
	- user
	- group
	- mode

	<%
	salt_master_subnet='10.0.1.0/24'
	db_subnet='10.0.2.0/24'
	app_subnet='10.0.3.0/24'
	%>

	- mcp-salt-master:
	- acl:
	- inbound:
	- {rule: 100, source: ${salt_master_subnet}, tcp: 22, allow-deny: 'ALLOW'}

	from fabric.api import *
	from fabric.operations import local,put
	import subprocess
	import os

	@task
	def deploy_small_ec2_instance():
	local('/usr/bin/ec2-run-instances ami-6dacf728 --instance-type m1.small --region us-west-1 --key ${EC2_KEYPAIR} --user-data-file user-data.sh --group ${SGROUP}')

	@task

	salt-minion:
	pkg:
	- installed
	service:
	- running
	- require:
	- pkg: salt-minion
	- watch:
	- file: /etc/salt/minion.d/grains.conf