Serving Rails Apps with RVM, Nginx, Unicorn and Upstart

Posted Saturday, January 29, 2011

Ever since reading GitHub’s blog post on Unicorn, I’ve been interested in trying it out. This post will document the process I used to get Unicorn serving a Rails application behind Nginx, with RVM managing Ruby. If you’ve read GitHub’s post, some of the config will look very familiar. Ideally, though, you should be able to follow this post from start to finish and have a working setup going.

Introduction

I installed this setup on Ubuntu 10.04 LTS Server Edition, 64-bit. You should be able to follow along pretty well on any sane system; that being said, I do use Upstart to manage the services toward the end of the guide. If you don’t use Upstart, you will need to substitute in your own SysVinit scripts (or scripts for whatever you use instead).

In a few listings, I use curl with Gist URLs to fetch the contents of files; the contents of these files are shown below the shell commands, for reference.

Installing RVM

Since we’ll use RVM to manage our Rubies and gemsets on the server, we’ll start with a server-wide install of RVM. We’ll start out by installing curl and git, if necessary, then RVM, and finally the other packages RVM asks us to install. (Be sure to pay attention to these; you can view them again via rvm notes. You may need to install additional packages for your distro of Linux or for the Rubies you wish to use). I’m using Ruby 1.9.2-p136 here.

We’ll also take care to add the current user to the ‘rvm’ group. Finally, we’ll create a user called ‘unicorn’ to own our test application, later.

# Install RVM and dependencies sudo aptitude install curl git-core sudo bash < <( curl -L http://bit.ly/rvm-install-system-wide ) sudo aptitude install build-essential bison openssl libreadline6 libreadline6-dev curl git-core zlib1g zlib1g-dev libssl-dev libyaml-dev libsqlite3-0 libsqlite3-dev sqlite3 libxml2-dev libxslt-dev autoconf libc6-dev sudo adduser `whoami` rvm echo 'source /usr/local/lib/rvm' >> ~/.bashrc # Set up users and groups sudo useradd --home /var/www --create-home --groups rvm unicorn && sudo chmod g+w /var/www sudo adduser `whoami` unicorn # # >> Log out and back in to SSH, open a new shell, etc. -- something to reload your environment # # Install Ruby 1.9.2-p136 and make it default rvm install ruby-1.9.2-p136 # Make a sandwich while you wait (or have someone make you one: http://xkcd.com/149/) rvm use ruby-1.9.2-p136 --defaultView Gist for 00_rvm.sh on GitHub

Installing and Configuring Nginx

For simplicity’s sake, we’ll be using Nginx from APT. To make sure we’re up to date, we’ll use Nginx’s PPA.

You can see in the configuration file that I’ve jumped the gun and included the location of the shared socket we’ll use with our Unicorn application.

# Install Nginx sudo bash -c 'echo "deb http://ppa.launchpad.net/nginx/stable/ubuntu $(lsb_release -cs) main" > /etc/apt/sources.list.d/nginx-stable-$(lsb_release -cs).list' sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys C300EE8C && sudo aptitude update sudo aptitude install nginx sudo bash -c 'curl -L https://gist.github.com/raw/802568/3a62636146eb2615cf42081b2574e8602d199658/nginx.conf > /etc/nginx/nginx.conf'View Gist for 01_nginx.sh on GitHub

/etc/nginx/nginx.conf:

worker_processes 1; user www-data www-data; pid /tmp/nginx.pid; error_log /tmp/nginx.error.log; events { worker_connections 1024; accept_mutex off; } http { include mime.types; default_type application/octet-stream; access_log /tmp/nginx.access.log combined; sendfile on; tcp_nopush on; tcp_nodelay off; gzip on; gzip_http_version 1.0; gzip_proxied any; gzip_min_length 500; gzip_disable "MSIE [1-6]\."; gzip_types text/plain text/html text/xml text/css text/comma-separated-values text/javascript application/x-javascript application/atom+xml; upstream unicorn_test { server unix:/var/www/test_app/tmp/sockets/unicorn.sock fail_timeout=0; } server { listen 80; client_max_body_size 4G; server_name _; keepalive_timeout 5; root /var/www/test_app/public; location / { proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header Host $http_host; proxy_redirect off; if (!-f $request_filename) { proxy_pass http://unicorn_test; break; } } error_page 500 502 503 504 /500.html; location = /500.html { root /var/www/test_app/public; } } }View Gist for etc_nginx.conf on GitHub

Configuring Upstart for Nginx

If you don’t use Upstart, or you don’t want to use Upstart, feel free to skip this section. By default, you can start Nginx with sudo /etc/init.d/nginx start.

sudo rm /etc/init.d/nginx for file in $(ls /etc/rc*/*nginx); do sudo rm $file; done sudo bash -c 'curl -L https://gist.github.com/raw/802568/e210f8754abdf137027daeb4c41db8cc301b36ad/nginx.conf > /etc/init/nginx.conf' sudo start nginxView Gist for 02_nginx_upstart.sh on GitHub

/etc/init/nginx.conf:

description "nginx http daemon" start on runlevel [2] stop on runlevel [016] console owner exec /usr/sbin/nginx -c /etc/nginx/nginx.conf -g "daemon off;" respawnView Gist for init_nginx.conf on GitHub

Creating a Sample Rails Application

Now we’ll create a test Rails application in /var/www/test_app. We’ll use a gemset called rails_app to demonstrate Unicorn’s ability to figure out which gemset it should use for our application (for more details on this, check out step four in my earlier post on Unicorn and Upstart). For this to work, we’ll also create an RVM wrapper for Unicorn. And, of course, don’t forget your config/unicorn.rb file.

Again, we’ll use Upstart to start and manage our Unicorn process, but you can use whatever you’d like. If you just want to test it out, try running unicorn -c /var/www/test_app/config/unicorn.rb from the ‘global’ gemset.

# Install Unicorn in the global gemset, and create a wrapper (yo yo yo in the hooouuuuuse!?) rvm use ruby-1.9.2-p136@global gem install unicorn --no-ri --no-rdoc rvm wrapper ruby-1.9.2-p136 r192 unicorn # Create and switch to a new gemset rvm gemset create rails_app && rvm gemset use rails_app gem install rails --no-ri --no-rdoc # Create a sample Rails application cd /var/www rails new test_app echo 'rvm use ruby-1.9.2-p136@rails_app --create' > test_app/.rvmrc cd test_app # # >> Accept the .rvmrc warning # echo "gem 'unicorn'" >> Gemfile && bundle install curl -L https://gist.github.com/raw/802568/998ac7c702e43d600f94fc3ee63ea05179315a0d/unicorn.rb > config/unicorn.rb sudo bash -c 'curl -L https://gist.github.com/raw/802568/ee3f5f320c34ec2e1d1b55521776d7dccd9140d4/test_app.conf > /etc/init/test_app.conf' sudo start test_appView Gist for 03_sample_app.sh on GitHub

/etc/init/test_app.conf:

description "Test rails application" start on runlevel [2] stop on runlevel [016] console owner exec /usr/local/rvm/bin/r192_unicorn -c /var/www/test_app/config/unicorn.rb respawnView Gist for test_app.conf on GitHub

/var/www/test_app/config/unicorn.rb:

APP_ROOT = File.expand_path(File.dirname(File.dirname(__FILE__))) if ENV['MY_RUBY_HOME'] && ENV['MY_RUBY_HOME'].include?('rvm') begin rvm_path = File.dirname(File.dirname(ENV['MY_RUBY_HOME'])) rvm_lib_path = File.join(rvm_path, 'lib') $LOAD_PATH.unshift rvm_lib_path require 'rvm' RVM.use_from_path! APP_ROOT rescue LoadError raise "RVM ruby lib is currently unavailable." end end ENV['BUNDLE_GEMFILE'] = File.expand_path('../Gemfile', File.dirname(__FILE__)) require 'bundler/setup' worker_processes 4 working_directory APP_ROOT preload_app true timeout 30 listen APP_ROOT + "/tmp/sockets/unicorn.sock", :backlog => 64 pid APP_ROOT + "/tmp/pids/unicorn.pid" stderr_path APP_ROOT + "/log/unicorn.stderr.log" stdout_path APP_ROOT + "/log/unicorn.stdout.log" before_fork do |server, worker| defined?(ActiveRecord::Base) && ActiveRecord::Base.connection.disconnect! old_pid = RAILS_ROOT + '/tmp/pids/unicorn.pid.oldbin' if File.exists?(old_pid) && server.pid != old_pid begin Process.kill("QUIT", File.read(old_pid).to_i) rescue Errno::ENOENT, Errno::ESRCH puts "Old master alerady dead" end end end after_fork do |server, worker| defined?(ActiveRecord::Base) && ActiveRecord::Base.establish_connection endView Gist for unicorn.rb on GitHub

Profit!

And that’s that! Upstart will manage both Nginx and Unicorn (although either could benefit from something like Monit or God, but I’ll leave that as an exercise for the reader and/or a future blog post).

Michelle Tilley

From the mind of a geek