How to Deploy Rails Application using Nginx with Unicorn

Steps for Unicorn & Nginx Deployment in Rails

Unicorn Configuration

1. Add unicorn in gem file

gem 'unicorn'

2. Create new file in config folder

$ vim config/unicorn.rb

Paste the below codes in unicorn.rb file

# set path to application

app_dir = File.expand_path("../..", __FILE__)

shared_dir = "#{app_dir}/shared"

working_directory app_dir

# Set unicorn options

worker_processes 2

preload_app true

timeout 30

# Set up socket location

listen "#{shared_dir}/sockets/unicorn.sock", :backlog => 64

# Logging

stderr_path "#{shared_dir}/log/unicorn.stderr.log"

stdout_path "#{shared_dir}/log/unicorn.stdout.log"

# Set master PID location

pid "#{shared_dir}/pids/unicorn.pid"

3. Create the folder were referred in unicorn.rb files

$  mkdir -p shared/pids shared/sockets shared/log

Unicorn init script setup

1. Create init script file

$  sudo vim /etc/init.d/unicorn_serversetup

2. Paste the below script in unicorn_serversetup file

#!/bin/sh

### BEGIN INIT INFO

# Provides:          unicorn

# Required-Start:    $all

# Required-Stop:     $all

# Default-Start:     2 3 4 5

# Default-Stop:      0 1 6

# Short-Description: starts the unicorn app server

# Description:       starts unicorn using start-stop-daemon

### END INIT INFO

set -e

USAGE="Usage: $0 <start|stop|restart|upgrade|rotate|force-stop>"

# app settings

USER="rajkumar"

APP_NAME="/Rajkumar/Projects/serversetup"

APP_ROOT="/home/$USER/$APP_NAME"

ENV="production"

# environment settings

PATH="/home/$USER/.rbenv/shims:/home/$USER/.rbenv/bin:$PATH"

CMD="cd $APP_ROOT && bundle exec unicorn -c config/unicorn.rb -E $ENV -D"

PID="$APP_ROOT/shared/pids/unicorn.pid"

OLD_PID="$PID.oldbin"

# make sure the app exists

cd $APP_ROOT || exit 1

sig () {

  test -s "$PID" && kill -$1 `cat $PID`

}

oldsig () {

  test -s $OLD_PID && kill -$1 `cat $OLD_PID`

}

case $1 in

  start)

    sig 0 && echo >&2 "Already running" && exit 0

    echo "Starting $APP_NAME"

    su - $USER -c "$CMD"

    ;;

  stop)

    echo "Stopping $APP_NAME"

    sig QUIT && exit 0

    echo >&2 "Not running"

    ;;

  force-stop)

    echo "Force stopping $APP_NAME"

    sig TERM && exit 0

    echo >&2 "Not running"

    ;;

  restart|reload|upgrade)

    sig USR2 && echo "reloaded $APP_NAME" && exit 0

    echo >&2 "Couldn't reload, starting '$CMD' instead"

    $CMD

    ;;

  rotate)

    sig USR1 && echo rotated logs OK && exit 0

    echo >&2 "Couldn't rotate logs" && exit 1

    ;;

  *)

    echo >&2 $USAGE

    exit 1

    ;;

esac

3. Give user name and app name and save the files

4. Update the script's permissions and enable Unicorn to start on boot:

  $ sudo chmod 755 /etc/init.d/unicorn_serversetup

  $  sudo update-rc.d unicorn_serversetup defaults 

5. start the unicorn 

  $  sudo service unicorn_serversetup start

6. Your application will run shared/sockets/unicorn.sock 

Install and Configure Nginx

1. $ sudo apt-get install nginx

2. $ sudo vi /etc/nginx/sites-available/default

3. configure below items

upstream app {

    # Path to Unicorn SOCK file, as defined previously

    server unix:/home/deploy/appname/shared/sockets/unicorn.sock fail_timeout=0;

}

server {

    listen 80;

    server_name localhost;

    root /home/deploy/appname/public;

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

    location @app {

        proxy_pass http://app;

        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

        proxy_set_header Host $http_host;

        proxy_redirect off;

    }

    error_page 500 502 503 504 /500.html;

    client_max_body_size 4G;

    keepalive_timeout 10;

}

4. $ sudo service nginx restart

5. Any 403 error you can check the sudo /var/log/nginx/error.log