Does anyone have an example where

docker_image

is an dependency? Meaning that some other targets depend on a docker image. e.g. running tests using that image, building another image using it as a base image, etc.

Have you tried something and it’s not working as you expect?

Thank you, I saw this and its previous post, but both example have very simple Dockerfile just adding PEX. What is the good practice if docker build is slow (e.g. with many

apt-get install

)? I only want to rerun when necessary. A few options I can think of are 1. Single Dockerfile with separate layer and rely on docker build cache -> difficult to reuse cache in CI/CD and sometimes save/load are still slow when the final image is big. 2. Use pants caching: Two dockerfile,

Dockerfile-base

adds some specific tag (e.g.

-t apt-installs-latest

) and the next

Dockerfile-main

uses it (

FROM apt-installs-latest

). Pants dependency could be set so that building

Dockerfile-main

depends on

Dockerfile-base

. With

--change-from

, it could skip building

Dockerfile-base

if not changed. -> relying on tag seems brittle Any thoughts?

Pants doesn’t directly cache docker image layers at the moment, so relying on docker build cache is required either way, unfortunately. Some relevant issues if you want to track them: https://github.com/pantsbuild/pants/issues/18287 https://github.com/pantsbuild/pants/issues/15199

Thank you so much! The issues are very relevant. I’ll look into them more.