FROM busybox RUN echo 'dockerio:x:1001:1001::/bin:/bin/false' >> /etc/passwd RUN echo 'dockerio:x:1001:' >> /etc/group RUN touch /exists RUN chown dockerio.dockerio /exists COPY test_file / RUN [ $(ls -l /test_file | awk '{print $3":"$4}') = 'root:root' ] RUN [ $(ls -l /test_file | awk '{print $1}') = '-rw-r--r--' ] RUN [ $(ls -l /exists | awk '{print $3":"$4}') = 'dockerio:dockerio' ]