Proxmox

• Download the base image

pveam update
pveam download <STOCKAGE> centos-7-default_20170504_amd64.tar.xz
mkdir ~/Workdir && cd ~/Workdir
tar -xJvf /mnt/pve/<STOCKAGE>/template/cache/centos-7-default_20170504_amd64.tar.xz
chroot .

• Once you are into the chroot, make your changes

echo "nameserver 80.67.169.12" > /etc/resolv.conf 
yum update
yum install php-fpm httpd php-mysql 
mkdir /var/log/httpd
systemctl enable httpd
systemctl enable php-fpm
echo "<?php echo 'Hello PHP world'; ?>" > /var/www/html/index.php
<CTRL+D>

Put it back in place

tar -cJvf /mnt/pve/<MONSTOCKAGE>/template/cache/mon-lamp-centos-a-moi.tar.xz .