Added a label :Z, because without it it does not work for CentOS7 with SELinux enabled - it cannot write files to the /shared/ directory
Details:
https://www.mankier.com/8/docker_selinux
http://manpages.org/docker-run
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux_atomic_host/7/html/container_security_guide/docker_selinux_security_policy