krb5: deploy, authenticate with, and manage a Kerberos 5 KDC
    
    The krb5 variable supports deploying a new containerized Kerberos 5 KDC (using the krb5-fedora image from
    https://pagure.io/krb5-fedora and quay.io/factory2/krb5-fedora). It provides methods for running admin
    commands (adding user and service principals), authenticating to the KDC, and running commands in an
    environment with a valid Kerberos ccache. It can be used to configure services for Kerberos authentication
    and validate their correct operation.