acr-cli Purge behavior differs from documentation

Describe the bug When I attempted to purge untagged images using the

acr purge
    --registry <Registry Name>
    --filter <Repository Name>:<Regex filter>
    --untagged

I received the following error Error: required flag(s) "ago" not set. So I added --ago 0d and the command went through, but it also deleted tagged images. My filter was set to repname:.* as I assumed the tag filter was irrelevant when you specify the --untagged switch. Setting the filter to repname:^$ fixed the problem, but the --untagged is still required. Omitting this switch results in no images being deleted. Is this behaviour expected?

So the working command was

acr purge
    --registry <Registry Name>
    --filter <Repository Name>:^$
    --ago 0d
    --untagged

Mar 02 '20 18:03 pikausp

In our process we rely heavily on "floating tags". The simplest of docker examples is the latest tag, this means we have a significant number of untagged manifests that it would be highly beneficial to be able to purge.

Sep 21 '20 23:09 SailingYYC

I came here with the same problem but after carefully reading the documentation twice, I realized that the --untagged parameter does not mean that it would delete only untagged images. It is meant to delete untagged images if they are available.

--untagged - Specifies that manifests that don't have associated tags (untagged manifests) are deleted.

Still, I believe many of us read that documentation to find a way to purge only untagged images, not deleting all images. I would suggest that Microsoft update that doc to show how to purge only untagged images.

Jul 06 '21 14:07 pitawatn

Exactly this. This needs to be clarified in the documentation and we need some information on how to only delete untagged manifests, but leave the tags in place.