Command line templating in Dockerfiles

Question

I am trying to build a Dockerfile that builds my project for multiple base images (e.g., Ubuntu 17.10 for multiple architectures)

I want to be able to write something like

FROM {{ ARCH }}/ubuntu:17.10
...

And have it resolve at build time to ubuntu:17.10 or ppc64le/ubuntu:17.10. Is there someway to do this?

Additionally a separate solution might be to have two docker files, but somehow include the common portions of the file into both the docker files.

Answer 1

You can use a build argument and use docker build --build-arg foo=bar to build the image.