warewulf4 is a rewrite of the well known warewulf cluster management tool in golang. With this new iteration its possible to leverage the possibilities which emerged with broad use of containers. The origins of warewulf4 is the hpcng community which is/was also behind projects like Apptainer (former known as Singularity), Centos and Rocky linux. A basic setup of a HPC cluster and the key concept of the configuration mechanism of warewulf4 are covered in this talk.