Rails, Unicorn and Nginx on Slackware

I was trying to deploy a Rails application using Apache and got into some problems when I tried to configure the app so that Apache will be the one that serves the precompiled assets (javascripts, css, images and others). Since I’m on tight deadline (yeah, I should’ve tested production mode much more earlier), I tried my luck with Nginx and it worked easily without any hassle. So, this is how I did it.

Goals

• Precompiled assets will be served by Nginx and not the Rails server itself.
• Assets will be served in gzip.

Environments

• Slackware v14
• Rails v3.2.10
• Ruby v1.9.3

Guides

First of all, install nginx from Slackbuild.

Be sure to turn off Apache’s startup script if you have it installed:

chmod -x /etc/rc.d/rc.httpd

This is to ensure no conflict since both of them by default will use port 80.

Put unicorn in your Gemfile and run bundle.

I’m putting my Rails app in /opt/neuro, so, adjust it accordingly.

Create nginx.conf in /opt/neuro/config/nginx.conf:

upstream neuro {
  server unix:/tmp/unicorn.neuro.sock fail_timeout=0;
}

server {
  listen neuro.husmnet:80;
  server_name neuro.husmnet
  root /opt/neuro/public;

  location ^~ /assets/ {
    root /opt/neuro/public;
    gzip_static on;
    expires max;
    add_header Cache-Control public;
  }

  try_files $uri/index.html $uri @unicorn;

  location @unicorn {
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_redirect off;
    proxy_pass http://neuro;
  }

  error_page 500 502 503 504 /500.html;
  client_max_body_size 4G;
  keepalive_timeout 10;
}

Create unicorn.rb in /opt/neuro/config/unicorn.rb

root = "#{Dir.pwd}"

# Define worker directory for Unicorn
working_directory root

# Location of PID file
pid "#{root}/tmp/pids/unicorn.pid"

# Define Log paths
stderr_path "#{root}/log/unicorn.log"
stdout_path "#{root}/log/unicorn.log"

# Listen on a UNIX data socket
listen "/tmp/unicorn.neuro.sock", :backlog => 64
# houllisten 8080, :tcp_nopush => true

worker_processes 2

# Load rails before forking workers for better worker spawn time
preload_app true

# Restart workes hangin' out for more than 240 secs
timeout 240

Replace /etc/nginx/nginx.conf with this content:

# user  root;
worker_processes  1;

error_log  /var/log/nginx/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/nginx.pid;

events {
  worker_connections  1024;
}

http {
  include       mime.types;
  default_type  application/octet-stream;

  sendfile        on;

  keepalive_timeout  65;

  gzip  on;

  include /etc/nginx/sites-enabled/*;
}

Create sites-enabled directory in /etc/nginx and create a softlink to the nginx.conf in our app:

$ mkdir /etc/nginx/sites-enabled
$ ln -s /opt/neuro/config/nginx.conf neuro.conf

Create a directory for the pid

$ mkdir /opt/neuro/tmp/pids

Before starting it for the first time, let us monitor important logs (open it using different terminals) :

$ tail -f /var/log/nginx/error.log
$ tail -f /opt/neuro/log/unicorn.log

Make sure you’ve precompiled your assets:

$ rake assets:clean
$ rake assets:precompile

Start unicorn:

$ cd /opt/neuro
$ unicorn -c config/unicorn.rb -E production -D

Start nginx:

$ nginx

Congratulation! Make sure there’s no error in your logs. If there’re, you can use these commands to stop nginx and unicorn to start everything back:

$ nginx -s stop
$ killall unicorn

Let’s test the gzip compression using curl:

$ curl -LI --compressed http://neuro.husmnet/

You’ll get something like this (notice the gzip info):

HTTP/1.1 200 OK
Server: nginx/1.2.2
Date: Sat, 05 Jan 2013 21:00:26 GMT
Content-Type: text/html; charset=utf-8
Connection: keep-alive
Status: 200 OK
X-UA-Compatible: IE=Edge,chrome=1
ETag: "a66ac1d43d8f07ecc0737e64dd8a3366"
Cache-Control: max-age=0, private, must-revalidate
Set-Cookie: _neuro_session=BAh7B0kiD3Nlc3Npb25faWQGOgZFRkkiJTQ2YTU2NjE3MDY0Y2RkNzk0Yzk3ODhhNDJlYmQ3ODA3BjsAVEkiEF9jc3JmX3Rva2VuBjsARkkiMVNvOXVTS2I2RXJIcTljbS9WeGRDODZyTUpVZENXL2NPVnJhTGR0V2xydGM9BjsARg%3D%3D--173e9d56a5cc434eb675b6626d90aced1cc17cd6; path=/; HttpOnly
X-Request-Id: 760e233de4980dc75169f2c68a53dc31
X-Runtime: 0.017885
X-Rack-Cache: miss
Content-Encoding: gzip

I admit, this is a very simple config, but it’s good enough for a beginner like me to get started. So, good luck!