FROM busybox RUN echo 'dockerio:x:1001:1001::/bin:/bin/false' >> /etc/passwd RUN echo 'dockerio:x:1001:' >> /etc/group RUN mkdir /exists RUN touch /exists/exists_file RUN chown -R dockerio.dockerio /exists COPY test_file1 test_file2 /exists/ ADD test_file3 test_file4 https://docker.com/robots.txt /exists/ RUN [ $(ls -l / | grep exists | awk '{print $3":"$4}') = 'dockerio:dockerio' ] RUN [ $(ls -l /exists/test_file1 | awk '{print $3":"$4}') = 'root:root' ] RUN [ $(ls -l /exists/test_file2 | awk '{print $3":"$4}') = 'root:root' ] RUN [ $(ls -l /exists/test_file3 | awk '{print $3":"$4}') = 'root:root' ] RUN [ $(ls -l /exists/test_file4 | awk '{print $3":"$4}') = 'root:root' ] RUN [ $(ls -l /exists/robots.txt | awk '{print $3":"$4}') = 'root:root' ] RUN [ $(ls -l /exists/exists_file | awk '{print $3":"$4}') = 'dockerio:dockerio' ]