upstart node.js can't save files, wrong permissions?

I got my own linode server the other day and moved a small nodejs / express I was playing around with over from an aws linux. Everything works great, but if I launch the app with upstart it doesnt run with the right permissions and can't write files to disk. I tried all kinds of variations of the upstart script, as root, as my username, www-data and nothing works. I set the public directory of express to 777 even just as a test but no luck. I start my upstart job with sudo start now-images-manager. When I run ps -ef I get the following output:

root     25150     1  0 11:26 ?        00:00:00 sudo node /home/myusername/sites/now-images-manager/app.js
root     25151 25150  0 11:26 ?        00:00:03 node /home/myusername/sites/now-images-manager/app.js

Here is my upstart script:

#!upstart
description "now-images-manager startup script"
author      "me@me.com"

start on startup
stop on shutdown

script
    export HOME="/root"
    echo $ > /var/run/now-images-manager.pid
    exec sudo node /home/myusername/sites/now-images-manager/app.js >> /home/myusername/sites/now-images-manager/now-images-manager.sys.log 2>&1
    # exec sudo -u myusername /usr/bin/node /home/myusername/sites/now-images-manager/app.js >> /home/myusername/sites/now-images-manager/now-images-manager.sys.log 2>&1
end script

pre-start script
    # Date format same as (new Date()).toISOString() for consistency
    echo "[`date -u +%Y-%m-%dT%T.%3NZ`] (sys) Starting" >> /var/log/now-images-manager.sys.log
end script

pre-stop script
    rm /var/run/now-images-manager.pid
    echo "[`date -u +%Y-%m-%dT%T.%3NZ`] (sys) Stopping" >> /var/log/now-images-manager.sys.log
end script

Here is a sample from the log:

downloadFileFromURL  { [Error: ENOENT, open 'public/images/tumblr_m9h1uh4KSi1qzl9k6o1_500.jpg']
  errno: 34,
  code: 'ENOENT',
  path: 'public/images/tumblr_m9h1uh4KSi1qzl9k6o1_500.jpg' }
When I start the app with node app.js in the shell it works perfectly fine.