When configuring

docker_image

targets, would it be useful/are there any plans to include a

version

property and for this to be available as a placeholder

{version}

for tagging? This would be useful for more complex tag formats e.g. if I wanted to add build and commit info into version tags like so for every docker image that would be built:

reg.address/docker/repo:v1.2-build5-fd6s82hr

It would also be useful to be able to set the

image_tags

in

pants.toml

if the format is consistent for an entire registry. This could then use the

{version}

placeholder (+ env vars) to create tag formats like:

[docker.registries.reg0]
image_tags = ["{version}-build{BUILD_NUM}-{GIT_COMMIT}"]

Currently to do the above I’d have to set up a plugin or set that format for every

docker_image

target AFAIK. Are there any plans for something close to this or should I look to just write a plugin for now? 🙂

I think you could do that with a macro around

docker_image

today. <https://www.pantsbuild.org/docs/macros> snippet:

commit_sha = env("CI_COMMIT_SHA")
    if commit_sha:
        image_tags.append(commit_sha)
        extra_build_args.append(f"COMMIT_SHA={commit_sha}")
    if env("CI_COMMIT_SHORT_SHA"):
        image_tags.append(env("CI_COMMIT_SHORT_SHA"))
    if env("CI_COMMIT_REF_PROTECTED") == "true":
        image_tags.append(f"protected-{env('CI_COMMIT_SHA')}")
    if env("CI_COMMIT_BRANCH") == "main":
        image_tags.append("latest")

Regarding

image_tags

in

pants.toml

see

extra_image_tags

here: https://www.pantsbuild.org/docs/tagging-docker-images#configuring-registries

I assumed that the “extra” implied that the way that tags should be set primarily is in the

docker_image

target

image_tags

. So I guess my second suggestion was more around best practice.

The

extra

was meant to highlight the fact that it doesn’t replace any image tags on the

docker_image

but adds to them. Perhaps

additional_image_tags

would’ve been better, but that’s getting unwieldy.. 😛

Ah that makes sense. What is your opinion on the idea of setting image tags like I described? Since we can already pull info for placeholders from the image target like

{name}

you can set your own placeholders using build args (https://www.pantsbuild.org/docs/tagging-docker-images#using-env-vars-to-include-dynamic-data-in-tags), or do the interpolation your self using env vars in the BUILD file (using

env

) — so it is not clear to me what beyond that you are suggesting (besides easier to use syntax?)

I was suggesting two things: 1, having another dynamic(?) placeholder (to be used in pants.toml) that comes from the

docker_image

target, in the same way that

{name}

does but for the version of the image. But currently

docker_image

doesn’t have a version property, so 2 would be adding that version property. I was wondering if this sounds like anything would be possible in future, basically. As I’m happy to write a plugin that does it for me for now if need be. :)

there is https://www.pantsbuild.org/docs/reference-docker_image#codeextra_build_argscode

docker_image(
  extra_build_args=["VERSION=1.2"],
  image_tags=["{build_args.VERSION]"],
)

so, it’s not in a dedicated field, but it is set on the target..