Docker Image using Packer and Ansible

To generate the docker image for the express app (app.tar.gz), install packer, docker and run

# check the express application 
tar -zxf app.tar.gz
rm app.tar.gz
cd app

# compress express application back (make sure the name is app.tar.gz)
tar -czf  app.tar.gz ./app

# paste the startup script in startup.sh

# cross check the ansible customizations in common.yaml 

packer validate packer.json
packer build packer.json
# wait for some time
docker run -p 3000:3000 <image_id_form_build_log> &

Reference https://ixis.co.uk/blog/pack-it-packaging-docker-images-packer#comment-1460