copying files using cp in dockfile fails

Question

I want to copy one file from one directory to another in an ubuntu image in a dockfile. I tried RUN cp make/A.mk ./B.mk RUN make -j4 But it failed. Anyone can help me fix the problem? Thanks

Answer 1

This is not the recommended method, in order to copy a file, you have

ADD https://docs.docker.com/engine/reference/builder/#add

and

COPY https://docs.docker.com/engine/reference/builder/#copy

in a Dockerfile

see What is the difference between the `COPY` and `ADD` commands in a Dockerfile? for example