How best to use with multi-stage?

[sVattic]

Love the tool idea. I am wondering how best to use ansible-bender with multi-stage builds.

In the Docker world, I can leave build dependencies behind by using two images:

FROM some-large-image as temp

RUN install the many build requirements...
RUN make


FROM clean-smaller-image
COPY --from=temp /result /dist
CMD ["/prod"]

With ansible-bender, I can see how to make the first image but not the second.
What do you think?

[TomasTomecek]

I think this could be doable by mounting the same host path to both container image builds:

$ ansible-bender build --build-volumes /path first-playbook.yaml
$ ansible-bender build --build-volumes /path second-playbook.yaml

I agree it would be lovely to get native support in bender for multi-stage builds.

[sVattic]

Oh, that makes sense! That's a perfect workaround for now.

[TomasTomecek]

okay, so let's treat this issue as a lack of documentation

[slopedog]

Just found this after leaving a comment on Tomáš's blog. Here's a different way I found to do this:

- name: Start up compile image container
  delegate_to: localhost
  shell: |
    set -e
    buildah rm compile-container || true
    buildah from --name compile-container compile-image
    buildah mount compile-container
  register: compile_img_path
  changed_when: false
  tags: no-cache

- set_fact:
    compile_img_path: "{{ compile_img_path.stdout_lines[-1] }}"

This will put the source image's local filesystem path in the variable compile_img_path, and you can copy things from there.

[cognifloyd]

Maybe a mode where each play gets treated as a separate image (or layer)?

[irhawks]

However, currently mounting using overlay in rootless mode is not supported. when buildah mount compile-container as a non-root user, an exception raises:

$ buildah mount pulsar-all-temp
cannot mount using driver overlay in rootless mode. You need to run it in a `buildah unshare` session