【Docker】CentOS8のDockerイメージでsystemctlを実行しようとすると「System has not been booted with systemd as init system (PID 1). Can’t operate.」と出る

docker run -d --privileged --name centos8 centos:8 /sbin/init
docker exec -it 93cf198ff349 /bin/bash

dnf -y install httpd
systemctl start httpd