FROM busybox ADD test.tar / RUN cat /test/foo | grep Hi ADD test.tar /test.tar RUN cat /test.tar/test/foo | grep Hi ADD test.tar /unlikely-to-exist RUN cat /unlikely-to-exist/test/foo | grep Hi ADD test.tar /unlikely-to-exist-trailing-slash/ RUN cat /unlikely-to-exist-trailing-slash/test/foo | grep Hi RUN mkdir /existing-directory ADD test.tar /existing-directory RUN cat /existing-directory/test/foo | grep Hi ADD test.tar /existing-directory-trailing-slash/ RUN cat /existing-directory-trailing-slash/test/foo | grep Hi