Dockerfile

ARG VERSION=7

FROM centos:${VERSION}
LABEL maintainer="HIFIS (https://www.hifis.net)"
ENV container=podman

# Install systemd -- See https://hub.docker.com/_/centos/
RUN yum -y update; yum clean all; \
(cd /lib/systemd/system/sysinit.target.wants/; for i in *; do [ $i == systemd-tmpfiles-setup.service ] || rm -f $i; done); \
rm -f /lib/systemd/system/multi-user.target.wants/*;\
rm -f /etc/systemd/system/*.wants/*;\
rm -f /lib/systemd/system/local-fs.target.wants/*; \
rm -f /lib/systemd/system/sockets.target.wants/*udev*; \
rm -f /lib/systemd/system/sockets.target.wants/*initctl*; \
rm -f /lib/systemd/system/basic.target.wants/*;\
rm -f /lib/systemd/system/anaconda.target.wants/*;

# Install requirements.
RUN yum makecache fast \
 && yum -y install deltarpm epel-release initscripts wget \
 # Install a systemd version which support cgroupsv2
 && wget https://copr.fedorainfracloud.org/coprs/jsynacek/systemd-backports-for-centos-7/repo/epel-7/jsynacek-systemd-backports-for-centos-7-epel-7.repo -O /etc/yum.repos.d/jsynacek-systemd-centos-7.repo \
 && yum -y update \
 && yum -y install \
      sudo \
      which \
 && yum clean all

# Disable requiretty.
RUN sed -i -e 's/^\(Defaults\s*requiretty\)/#--- \1/'  /etc/sudoers

CMD ["/usr/lib/systemd/systemd"]