BuildKit is a good tool for building Docker images on a Kubernetes cluster where you have root access.
Kaniko is another usable tool but it is not as intuitive as buildkit
-cli -for -kubectl to use. As a matter of fact, tricky issues might arise when building Docker images using Kaniko. buildah is a tool that facilitates building OCI images. It can be use on Kubernetes too but is quite complicated to configure and is not as popular as Kaniko currently.