Got a docker question. I'd like to avoid proliferating our AWS ECR registry ID around our repo (since it's complicated). The

pants.toml

setting was great to set up something like

[docker.registries.aws-ecr]

so that I could refer to them. However, one of my images depends on a base image we store in that registry. It seems like I still have to do

FROM <my long registry ID>/<image name>:<image tag>

instead of just

FROM <image name>:<image tag>

. My target configuration looks like this

docker_image(
    name = "gnc_ground",
    registries = ["@aws-ecr"],
    tags = ["ground_software_service"],
)

In a non-Pants use of Docker, I’ve done:

ARG base_image
FROM ${base_image}

Hmm, so maybe I can use build_args to configure that globally

Yeah, perhaps support to pickup registry addresses as build args would be useful; but the workaround you found is ok, only not DRY.

Yeah, at least the duplication is collocated in

pants.toml

so it's not too bad for now.

Note as well as there is magic in place if you ever need to use another docker_image target as base..

I did a slightly modified version of this where I set

[docker]
build_args = ["ECR_ID=<my registry ID>"]

and then in the Dockerfile, I did

ARG ECR_ID
FROM ${ECR_ID}/<base image>:<image tag>

. Hopefully that keeps each

Dockerfile

more tunable.