====== わが子に命令したこと ======
  sudo yum remove docker docker-common docker-selinux docker-engine
  sudo yum install -y yum-utils device-mapper-persistent-data lvm2
  sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
  sudo yum makecache fast
  sudo yum install docker-ce
  sudo systemctl start docker
  sudo groupadd docker
  sudo usermod -aG docker $USER
  sudo systemctl enable docker

  docker pull gitlab/gitlab-ce

  sudo yum install java-1.6.0-openjdk