Think of it as a VM without the performance penalty of having a VM. It uses all sorts of trickery to make authoring of these images a painless experience and contains a central repo where users can share images. The concept is that developers and sysadmins can author simple images, usually authored using Dockerfiles that provide a pristine state that encapsulate an application. Last week I decided to spend some time experimenting with DockerĪn open source project to pack, ship and run any application as a lightweight container

This is why we often outsource the task to application as a service providers. Yes, we have passenger, however, getting it installed and working with rvm/rbenv is a bit of a black art, and let us not mention daemonizing Sidekiq or Resque. You would think that years along we would have made some progress in this front, but no, deploying Rails is almost as complicated as it was back in the mongrel days. Deploying Rails applications is something we all struggle with:

Download phpbb docker