errordeveloper/Unicorn_and_Upstart.md

## Unicorn_and_Upstart.md

      
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              Unicorn_and_Upstart.md
            
          
    Using Unicorn with Upstart

This configuration works with Upstart on Ubuntu 12.04 LTS
The reason why it needs to be done this way (i.e. with the pre-start and post-stop stanzas), is because Upstart
is unable to track whever Unicorn master process re-execs itself on hot deploys. One can use it without hot-deploys
and run Unicorn in foreground also, it then only needs one exec stanza.
This presumes you are not using RVM, so no voodoo dances.
#/etc/init/my-app.conf
description "My App"
author "Ilya Dmitrichenko <errordeveloper@gmail.com>"

start on virtual-filesystems
stop on runlevel [06]

env PATH=/opt/ruby/shims:/opt/ruby/rbenv/bin:/usr/local/bin:/usr/bin:/bin

env RAILS_ENV=production

setuid nobody
setgid nobody

chdir /opt/my_app/

pre-start exec ./bin/unicorn_rails -D -c /opt/my_app/config/unicorn.rb --env production

post-stop exec kill `cat /opt/my_app/run/unicorn.pid`

The next example allows one to run a very descriptive command
from their deploy script:
initctl emit my-app-deploy TAG=v1.2.3`.

It demonstrates a very appropriate use of Upstart's events.
Please also note that it can be used for roll-back just as well.
#/etc/init/my-app-deploy-task.conf
description "Upgade My App!"
author "Ilya Dmitrichenko <errordeveloper@gmail.com>"

on my-app-deploy

task

console log

env PATH=/opt/ruby/shims:/opt/ruby/rbenv/bin:/usr/local/bin:/usr/bin:/bin

chdir /opt/my_app/

script
  git fetch --quiet --all --tags origin
  git checkout --quiet --force --detach $TAG
  bundle --quiet install
  kill -USR2 `cat ./run/unicorn.pid`
end script