$ sudo usermod -aG docker [non-root user]
##########################################
# Dockerfile to change from root to
# non-root privilege
###########################################
# Base image is CentOS 7
FROM Centos:7
# Add a new user "john" with user id 8877
RUN useradd -u 8877 john
# Change to non-root privilege
USER john
sudo setfacl -m user:$USER:rw /var/run/docker.sock