Adding annotation/label to a container-image without creating the container first

[tarun360]

For adding some annotations/labels to a image, we first have to create the container from the image, and then we can add some annotations/labels using buildah-config: buildah-config [options] containerID

But this requires first creating a container from image, then adding the required annotation/label, and then committing the changes back to an image.

But creating a container just for making some small change to the image configuration seems a unnecessary step which would take additional time and memory.

Is there a better way to add annotations/labels to a image?

[flouthoc]

Hi @tarun360 I don't think buildah can modify existing container image in storage, maybe skopeo is better candidate for this but @vrothberg and @mtrmac can confirm better if skopeo can do this or plan to do this in future or not.

[vrothberg]

Thanks for reaching out! Skopeo does not ship such a functionality. As pointed out, buildah config operates on a (build) container but a command to alter an image sounds reasonable to me.

[mtrmac]

Editing configs of images has, so far, been out of Skopeo’s scope. I agree Buildah is the appropriate tool.

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WRT changing Buildah not to use a container in such situations, I think it’s worth exploring but as someone not very familiar with Buildah (who saw the Containerfile processing loops and they are complex), I’m worried about the extra complexity.

[rhatdan]

@nalind @flouthoc WDYT?

[nalind]

Skipping the step where we create a rootfs if we don't end up needing one would be faster in the general case, but it's kind of baked into the API.