The workflow for building an OpenFaaS function involves creating a container image, pushing it into a registry and then deploying it into a cluster. That cluster could be remote, or running on your own PC, but during development this push and pull phase can cause a significant lag for testing changes.

In this blog post we’ll explore how to test out kim, a new project written at Rancher Labs which can build a container image directly into a node’s image library. That means that we can shave off several seconds whenever we want to build a new function and deploy it compared to using faas-cli up with Docker or buildkit.

I also think it's important to cover prior art, so we do that where it belongs - in the introduction.

I'd be interested to know what you all are using to build images and accelerate your "inner loop". Are there any limitations or downsides?