Unicorn init.d script (chkconfig compatible) /etc/init.d/unicorn with example application configuration scripts

rpcm.conf

# starts all unicorns listed in /etc/unicorn/*.conf
# lives under /etc/unicorn/rpcm.conf

ENV=production
APP_ROOT=/opt/rpcm

unicorn.rb

# Example Unicorn configuration for sinatra app
# must live under <APP_ROOT>/config/unicorn.rb

APP_ROOT = File.expand_path '../', File.dirname(__FILE__)
 
worker_processes 2
  
working_directory APP_ROOT
 
pid "#{APP_ROOT}/tmp/unicorn.pid"
  
# This is where we specify the socket. 
# We will point the upstream nginx module to this socket later on 
listen "#{APP_ROOT}/tmp/sockets/unicorn.sock", :backlog => 64
# alternatively use "listen 8080" to listen on a tcp port 
 
stderr_path "#{APP_ROOT}/log/unicorn.stderr.log"
stdout_path "#{APP_ROOT}/log/unicorn.stdout.log"
 
before_fork do |server, worker|
  old_pid = "#{APP_ROOT}/tmp/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
      # someone else did our job for us
    end
  end
end

unicorn.sh

#!/bin/sh
#
# unicorn - init.d script for single or multiple unicorn installations. Expects at least one .conf
# chkconfig:   - 85 15
# description:  Unicorn is an HTTP server for Rack applications designed to only serve fast clients on low-latency,
#               high-bandwidth connections and take advantage of features in Unix/Unix-like kernels
# processname: unicorn
# config:      /etc/unicorn/*.conf
#
# Modified by wol
# based on http://gist.github.com/308216 by http://github.com/mguterl
#
## A sample /etc/unicorn/my_app.conf
##
## ENV=production
## APP_ROOT=/var/apps/www/my_app/current
#
# This configures a unicorn master for your app at /var/apps/www/my_app/current running in
# production mode. It will read config/unicorn.rb for further set up.
#
# You should ensure different ports or sockets are set in each config/unicorn.rb if
# you are running more than one master concurrently.
#
# If you call this script without any config parameters, it will attempt to run the
# init command for all your unicorn configurations listed in /etc/unicorn/*.conf
#
# /etc/init.d/unicorn start # starts all unicorns
#
# If you specify a particular config, it will only operate on that one
#
# /etc/init.d/unicorn start /etc/unicorn/my_app.conf

set -e

sig () {
  test -s "$PID" && kill -$1 `cat "$PID"`
}

oldsig () {
  test -s "$OLD_PID" && kill -$1 `cat "$OLD_PID"`
}

cmd () {

  case $1 in
    start)
      sig 0 && echo >&2 "Already running" && exit 0
      echo "Starting"
      $CMD
      ;;
    stop)
      sig QUIT && echo "Stopping" && exit 0
      echo >&2 "Not running"
      ;;
    force-stop)
      sig TERM && echo "Forcing a stop" && exit 0
      echo >&2 "Not running"
      ;;
    restart|reload)
      sig USR2 && sleep 5 && oldsig QUIT && echo "Killing old master" `cat $OLD_PID` && exit 0
      echo >&2 "Couldn't reload, starting '$CMD' instead"
      $CMD
      ;;
    upgrade)
      sig USR2 && echo Upgraded && exit 0
      echo >&2 "Couldn't upgrade, starting '$CMD' instead"
      $CMD
      ;;
    rotate)
            sig USR1 && echo rotated logs OK && exit 0
            echo >&2 "Couldn't rotate logs" && exit 1
            ;;
    *)
      echo >&2 "Usage: $0 <start|stop|restart|upgrade|rotate|force-stop>"
      exit 1
      ;;
    esac
}

setup () {

  echo -n "$APP_ROOT: "
  cd $APP_ROOT || exit 1
  export PID=$APP_ROOT/tmp/unicorn.pid
  export OLD_PID="$PID.oldbin"

  CMD="/usr/bin/unicorn -c config/unicorn.rb -E $ENV -D"
}

start_stop () {

  # either run the start/stop/reload/etc command for every config under /etc/unicorn
  # or just do it for a specific one

  # $1 contains the start/stop/etc command
  # $2 if it exists, should be the specific config we want to act on
  if [ $2 ]; then
    . $2
    setup
    cmd $1
  else
    for CONFIG in /etc/unicorn/*.conf; do
      # import the variables
      . $CONFIG
      setup

      # run the start/stop/etc command
      cmd $1
    done
   fi
}

ARGS="$1 $2"
start_stop $ARGS

hi niwo... i have a copy of your unicorn init.d script. my problem was that most of the time restarts failed. i started playing around with the sleep time and reducing it to sleep 2 fixed the issue. Any thought on that?

hi aslan!
My gist is based on the script found here: https://gist.github.com/504875.
Seems strange to me that 5 seconds of sleep would break the script, never experienced such behavior.

Hi niwo

I think the issue was indirectly related. I was trying to kill the old pid both in the init.d script and unicorn.rb. Most of the time unicorn.rb's before fork block did remove the old pid before the init.d and that would cause init.d to not exit properly. reducing the sleep to 2 seconds sometimes gave the init.d the time it required to kill the old pid before unicorn.rb did. Thats why i thought i was fixing the problem. I am not killing the old pid in the init.d any more and every thing seems to be working fine now. Any idea way a 5 second sleep was placed in the first place?