flavor's suffix not applied to `latest`

[porridge]

Contributing guidelines

• I've read the contributing guidelines and wholeheartedly agree

I've found a bug, and:

• The documentation does not mention anything about my problem
• There are no open or closed issues that are related to my problem

Description

I'm using the configuration pasted below and run this workflow on a v0.4.1 tag.

Expected behaviour

I'd expect the following tags according to docs:

          "quay.io/stackrox-io/image-prefetcher:v0.4.1-s390x",
          "quay.io/stackrox-io/image-prefetcher:v0.4-s390x",
          "quay.io/stackrox-io/image-prefetcher:v0-s390x",
          "quay.io/stackrox-io/image-prefetcher:sha-1f1047a-s390x",
          "quay.io/stackrox-io/image-prefetcher:latest-s390"

Actual behaviour

Instead results in the following tags:

          "quay.io/stackrox-io/image-prefetcher:v0.4.1-s390x",
          "quay.io/stackrox-io/image-prefetcher:v0.4-s390x",
          "quay.io/stackrox-io/image-prefetcher:v0-s390x",
          "quay.io/stackrox-io/image-prefetcher:sha-1f1047a-s390x",
          "quay.io/stackrox-io/image-prefetcher:latest"

Note the lack of suffix on the last line.

Repository URL

https://github.com/stackrox/image-prefetcher

Workflow run URL

https://github.com/stackrox/image-prefetcher/actions/runs/19629851352/job/56206761899#step:20:150

YAML workflow

- name: Prepare manifest OCI metadata for s390x
  id: meta-s390x
  uses: docker/metadata-action@v5
  with:
    images: "quay.io/stackrox-io/image-prefetcher"
    flavor: suffix=-s390x
    tags: |
      type=ref,event=branch,prefix=branch-
      type=semver,pattern=v{{major}}.{{minor}}.{{patch}}
      type=semver,pattern=v{{major}}.{{minor}}
      type=semver,pattern=v{{major}}
      type=sha

Workflow logs

Bake file definition (tags)
  {
    "target": {
      "docker-metadata-action": {
        "tags": [
          "quay.io/stackrox-io/image-prefetcher:v0.4.1-s390x",
          "quay.io/stackrox-io/image-prefetcher:v0.4-s390x",
          "quay.io/stackrox-io/image-prefetcher:v0-s390x",
          "quay.io/stackrox-io/image-prefetcher:sha-1f1047a-s390x",
          "quay.io/stackrox-io/image-prefetcher:latest"
        ],
        "args": {
          "DOCKER_META_IMAGES": "quay.io/stackrox-io/image-prefetcher",
          "DOCKER_META_VERSION": "v0.4.1-s390x"
        }
      }
    }
  }

logs_50625962950.zip

BuildKit logs

Additional info

No response

[polarathene]

The docs state that you need to use ,onlatest=true when you want the suffix applied to an implicitly added latest tag (which the default flavor.latest=auto does).

For more information see:

• Enable Flag in Raw Tag does not work as expected #461 (comment)
• Automatically Tag Latest Official Version with 'latest' in Docker Repository Based on Semantic Versioning #407 (comment)

---

Solution A

You just need to append ,onlatest=true in your case:

flavor: |
  latest=auto
  suffix=-s390x,onlatest=true

Solution B

You can avoid the flavor.latest=auto magic and manage latest explicitly:

flavor: |
  latest=false
  suffix=-s390x
tags: |
  type=raw,value=latest,enable={{ is_default_branch }}

NOTE: That enable condition should be adjusted to match your actual expectations for when it should enable the latest tag.

Roughly mimic flavor.latest=auto condition

Usage of any of these tags types will implicitly enable a latest tag as the docs explain when flavor.latest=auto would evaluate to flavor.latest=true:

• type=ref,event=tag (source: always true)
• type=semver,pattern=... (source: false if pre-release or invalid semver)
• type=pep440,pattern=... (source: false if pre-release or invalid pep440)
• type=match,pattern=... (source: always true)

NOTE:

• Those all rely on github.ref_type == 'tag' (a push event trigger from a tag rather than a commit), unless they were given an explicit value as input instead.
• latest will be determined by the first tags input entry processed by the action (which is dependent upon the sort order based on their associated priority attribute).
  • type=semver (900) / type=pep440 (900) > type=match (800) > type=ref (600)
  • When priority is the same value, the secondary sorting factor is the declaration order from the tags input.
  • If a different tag type from those four mentioned was given a higher priority (or already had higher by default, eg: type=schedule (1000)), then that tags default flavor.latest=auto logic is to set latest=false, preventing an implicitly added a latest tag.

So you should be able to mimic that behaviour with:

flavor: |
  latest=false
  suffix=-s390x
tags: |
  type=raw,value=latest,enable=${{ github.ref_type == 'tag' }}

If you were to provide a value explicitly and the ref type of the event trigger wouldn't be a tag, then you'll need to account for that as well. Alternatively, use the first suggestion with ,onlatest=true 👍

EDIT: Be mindful that this example did not handle pre-release semver tag detection like type=semver + type=pep440 support.

[porridge]

Thank you for the detailed response @polarathene ! I'll try this out soon.

[porridge]

FTR, "Solution A" worked flawlessly!