...
(master-node)# !!!!! modif: Master + Ansible Node
su
rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
yum update -y
yum install ansible pyOpenSSL python-cryptography python-lxml -y
yum install kernel-devel kernel-headers -y && reboot
(slave-node)#
su
rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
yum update -y
yum install kernel-devel kernel-headers nfs-utils socat -y && reboot
...