Building on top of @user3495504’s answer, what we did to fix the problem was adding an entry on top of the file /etc/yum.repos.d/docker-ce.repo, with this content:
[centos-extras]
name=Centos extras - $basearch
baseurl=http://mirror.centos.org/centos/7/extras/x86_64
enabled=1
gpgcheck=1
gpgkey=http://centos.org/keys/RPM-GPG-KEY-CentOS-7
Then the installation command:
yum -y install slirp4netns fuse-overlayfs container-selinux
was successful.
[Edit]
- enabled gpgcheck