Initializer or Gem not loaded with Unicorn causing 500 internal server error

Question

I deploy my application to an Ubuntu VPS. I followed the "deploy to VPS" railscast.

Everything went smooth, up until I added the following gem: https://github.com/marceldegraaf/sisow

On my local development machine it works like a charm, but after I deployed it to my production environment, the rails application will not start anymore (500 Internal Server Error).

I have tried a number of "tweaks" to my unicorn configuration, deploy.rb and a bunch of other files, but nothing seems to work.

The weird thing is that when I use:

RAILS_ENV=production bundle exec rails c

I can use the gem without any problems (?)

unicorn.log

E, [2012-05-25T16:38:14.742805 #27916] ERROR -- : reaped #<Process::Status: pid 5777 exit 1> worker=1
I, [2012-05-25T16:38:14.742998 #27916]  INFO -- : worker=1 spawning...
I, [2012-05-25T16:38:14.746132 #5803]  INFO -- : worker=1 spawned pid=5803
I, [2012-05-25T16:38:14.746557 #5803]  INFO -- : Refreshing Gem list
/home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:251:in `require': cannot load such file -- sisow (LoadError)
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:251:in `block in require'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:236:in `load_dependency'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:251:in `require'
    from /home/deployer/apps/my_app/releases/20120525140057/config/initializers/sisow.rb:1:in `<top (required)>'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:245:in `load'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:245:in `block in load'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:236:in `load_dependency'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:245:in `load'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/railties-3.2.0/lib/rails/engine.rb:588:in `block (2 levels) in <class:Engine>'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/railties-3.2.0/lib/rails/engine.rb:587:in `each'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/railties-3.2.0/lib/rails/engine.rb:587:in `block in <class:Engine>'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/railties-3.2.0/lib/rails/initializable.rb:30:in `instance_exec'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/railties-3.2.0/lib/rails/initializable.rb:30:in `run'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/railties-3.2.0/lib/rails/initializable.rb:55:in `block in run_initializers'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/railties-3.2.0/lib/rails/initializable.rb:54:in `each'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/railties-3.2.0/lib/rails/initializable.rb:54:in `run_initializers'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/railties-3.2.0/lib/rails/application.rb:136:in `initialize!'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/railties-3.2.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
    from /home/deployer/apps/my_app/releases/20120525140057/config/environment.rb:5:in `<top (required)>'
    from config.ru:4:in `require'
    from config.ru:4:in `block in <main>'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize'
    from config.ru:1:in `new'
    from config.ru:1:in `<main>'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/unicorn-4.3.1/lib/unicorn.rb:44:in `eval'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/unicorn-4.3.1/lib/unicorn.rb:44:in `block in builder'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/unicorn-4.3.1/lib/unicorn/http_server.rb:696:in `call'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/unicorn-4.3.1/lib/unicorn/http_server.rb:696:in `build_app!'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/unicorn-4.3.1/lib/unicorn/http_server.rb:569:in `init_worker_process'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/unicorn-4.3.1/lib/unicorn/http_server.rb:589:in `worker_loop'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/unicorn-4.3.1/lib/unicorn/http_server.rb:487:in `spawn_missing_workers'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/unicorn-4.3.1/lib/unicorn/http_server.rb:498:in `maintain_worker_count'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/unicorn-4.3.1/lib/unicorn/http_server.rb:272:in `join'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/gems/unicorn-4.3.1/bin/unicorn:121:in `<top (required)>'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/bin/unicorn:23:in `load'
    from /home/deployer/apps/my_app/shared/bundle/ruby/1.9.1/bin/unicorn:23:in `<main>'
E, [201

unicorn.rb

app_path = "/home/deployer/apps/my_app"
root = "/home/deployer/apps/my_app/current"
bundle_path = "#{app_path}/shared/bundle"
working_directory root
pid "#{root}/tmp/pids/unicorn.pid"
stderr_path "#{root}/log/unicorn.log"
stdout_path "#{root}/log/unicorn.log"

listen "/tmp/unicorn.my_app.sock"
worker_processes 4
timeout 30

before_exec do |server|                                                         
  ENV["BUNDLE_GEMFILE"] = "#{root}/Gemfile"                               
end

unicorn_init.sh

#!/bin/sh
set -e

# Feel free to change any of the following variables for your app:
TIMEOUT=${TIMEOUT-60}
APP_ROOT=/home/deployer/apps/my_app/current
PID=$APP_ROOT/tmp/pids/unicorn.pid
CMD="cd $APP_ROOT; bundle exec unicorn -D -c $APP_ROOT/config/unicorn.rb -E production"
AS_USER=deployer
set -u

OLD_PIN="$PID.oldbin"

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

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

run () {
  if [ "$(id -un)" = "$AS_USER" ]; then
    eval $1
  else
    su -c "$1" - $AS_USER
  fi
}

case "$1" in
start)
  sig 0 && echo >&2 "Already running" && exit 0
  run "$CMD"
  ;;
stop)
  sig QUIT && exit 0
  echo >&2 "Not running"
  ;;
force-stop)
  sig TERM && exit 0
  echo >&2 "Not running"
  ;;
restart|reload)
  sig HUP && echo reloaded OK && exit 0
  echo >&2 "Couldn't reload, starting '$CMD' instead"
  run "$CMD"
  ;;
upgrade)
  if sig USR2 && sleep 2 && sig 0 && oldsig QUIT
  then
    n=$TIMEOUT
    while test -s $OLD_PIN && test $n -ge 0
    do
      printf '.' && sleep 1 && n=$(( $n - 1 ))
    done
    echo

    if test $n -lt 0 && test -s $OLD_PIN
    then
      echo >&2 "$OLD_PIN still exists after $TIMEOUT seconds"
      exit 1
    fi
    exit 0
  fi
  echo >&2 "Couldn't upgrade, starting '$CMD' instead"
  run "$CMD"
  ;;
reopen-logs)
  sig USR1
  ;;
*)
  echo >&2 "Usage: $0 <start|stop|restart|upgrade|force-stop|reopen-logs>"
  exit 1
  ;;
esac

Gemfile

source 'http://rubygems.org'

gem 'rails', '3.2.0'
gem "net-ssh", "~> 2.5.1"

# Bundle edge Rails instead:
# gem 'rails',     :git => 'git://github.com/rails/rails.git'

gem 'pg'
gem "cocoon"
gem 'nokogiri'
gem 'hpricot'
gem "formtastic", "~> 2.1.1"
gem "activeadmin", "~> 0.4.4"
gem 'omniauth'
gem 'country-select'
gem "paperclip", "~> 3.0"
gem 'cancan'
gem 'rolify'

gem "meta_search",    '>= 1.1.0.pre'
gem 'bourbon', "~> 2.0.0.rc1"
gem "rails-boilerplate"
gem 'geocoder'
gem 'httparty'
gem 'hashie'
gem 'will_paginate', :git => "git://github.com/mislav/will_paginate.git"
gem 'thinking-sphinx', '2.0.10'
gem 'sanitize'
gem 'feedzirra'
gem "crypt19", "~> 1.2.1"
gem 'wicked_pdf'
gem 'forem', :git => "git://github.com/radar/forem.git"
gem 'thin'
gem 'whenever', :require => false
gem "ckeditor", "3.7.1"
gem 'sisow'

# Gems used only for assets and not required
# in production environments by default.
group :assets do
  gem 'sass-rails',   '~> 3.2.3'
  gem 'coffee-rails', '~> 3.2.1'
  gem 'uglifier', '>= 1.0.3'
end

gem 'haml-rails' 
gem 'jquery-rails'

group :development do
    gem 'ruby_parser'
end


# To use ActiveModel has_secure_password
# gem 'bcrypt-ruby', '~> 3.0.0'

# Use unicorn as the web server
gem 'unicorn'

# Deploy with Capistrano
gem 'capistrano'

# To use debugger
# gem 'ruby-debug19', :require => 'ruby-debug'

Answer 1

I had the exact same issue. Restarting the unicorn service fixed it for me:

/etc/init.d/unicorn_my_app stop
/etc/init.d/unicorn_my_app start

Credit goes to: https://github.com/jdutil/contact_us/issues/15#issuecomment-7954768.

Answer 2

I've had the exact same problem (although with different gem - icalendar). I tried many things but what helped me eventually was to reinstall ruby (via rbenv), cleanup gems, remove the app from server, add this to my unicorn.rb:

before_exec do |server| 
  ENV["BUNDLE_GEMFILE"] = "/path/to/app/current/Gemfile" 
end

and finally make fresh deploy from the beginning (deply:setup).

I'm not 100% sure about the solution (it was quite a mess in the end) but I hope it'll help you too.