it seems the CentOS 7 NetInstall.iso images of CentOS do not come with any packages…

so you will have to provide a mirror, University https://rwth-aachen.de does a magnificent job with that, even properly configured https (!)

so what you do is

  1. Networking is disabled per default, go to Network and put it to „on“
  2. go to software and type: https://ftp.halifax.rwth-aachen.de/centos/7.6.1810/os/x86_64/

admin