buildah is a (daemon-free) container build utility

The Buildah package provides a command line tool that can be used to

* create a working container, either from scratch or using an image as a
  starting point
* create an image, either from a working container or via the instructions in a
  Dockerfile
* images can be built in either the OCI image format or the traditional
  upstream docker image format
* mount a working container's root filesystem for manipulation
* unmount a working container's root filesystem
* use the updated contents of a container's root filesystem as a filesystem
  layer to create a new image
* delete a working container or an image
* rename a local container

For examples, see:
* https://github.com/containers/buildah or /usr/doc/buildah-*/README.md
* man pages

non-root usage:

plenty of kernel recent kernel's support the user-namespace sub uid/gid
mapping. Only recent versions of shadow-utils will append a new mapping for
users when they are created. You may have to add a mapping for your user like
so:

```shell
echo "$YOURUSER:100000:65536" > /etc/subuid
echo "$YOURGROUP:100000:65536" > /etc/subgid
```

if you have more than one non-root user to add a mapping for, then their start
number (like `100000` above) would begin after 100000+65536.