Hi team, When using the

docker_image

target in Pants the

COPY

command in a

Dockerfile

appears to bypass

.dockerignore

logic (

COPY folder folder

) if the files are matched by

files(
sources=[
    "folder/**/*"]
)

in BUILD. All files are materialized in the build sandbox and subsequently copied into the image, even if they are listed in

.dockerignore

. While I can use

!

exclusions in the

BUILD

file, should not pants honors the

.dockerignore

file automatically to be more compliant with the Docker/Podman?

cc @curved-television-6568 does this ring a bell? It does look like we don't reference .dockerignore at all, so I would consider this a bug

Well, yes and no. It's all "by design" (even when/if lacking 😂 ) What's happening is that pants is responsible for materializing files in the sandbox for the docker build context, and pants does not consult

.dockerignore

Then when pants runs

docker build

using the sandbox as build context, it (i.e. docker) will respect any

.dockerignore

in the sandbox meaning, you'll need to make sure that pants materializes it there, by including

.dockerignore

in some valid target source type that is a dependency of your

docker_image

I will open an issue and create a tiny repo as soon as I have more time. I guess including the

.dockerignore

files by default into the sandbox is the best and simplest approach for now. Maybe adding a parameter (feature flag) to

pants.toml

in order to activate it (and adding a deprecation warning that in future releases the behaviour will change) would be the safest approach to prevent unexpected behaviours when updating the pants version.