server@7061c59ea636

This is not an image: it is a BuildKit attestation entry of a multi-arch index.

docker buildx stores the attestations it generates as an extra entry of the index, with the placeholder platform unknown/unknown, describing the variant b77a52f63391. It appears whenever a build records provenance — on by default since Docker 24 / buildx 0.11 — or an SBOM (--sbom=true); images built with plain docker build or with --provenance=false have no such entry. docker pull never fetches it by itself; docker buildx imagetools inspect and docker sbom read it.

This entry contains: SLSA provenance v1 (25.1 KiB) — no SBOM: the build did not pass --sbom=true.

It belongs to server:0.4.2, so it cannot be deleted on its own: removing it would break that index. Delete the tag or the index and the next prune untagged run (or a retention policy) removes this entry; garbage collection reclaims its bytes.

To build without attestation entries: docker buildx build --provenance=false --sbom=false …

docker pull chicor.ee/tund/server@sha256:7061c59ea6361cd9a660a497aa83897442feb2ac10981ac7d94cdbea38574daf

Digest: 7061c59ea6361cd9a660
Media type: application/vnd.oci.image.manifest.v1+json
Platform: none — attestation entry (unknown/unknown)
Total size: 25.1 KiB
Pushed: Oct 6, 2026byruohki

Cargo plan

1 layer25.1 KiB

#	Instruction	Digest	Shared	Size
1	`—`	60d4368f1cf8	unique	25.1 KiB

{
  "schemaVersion": 2,
  "mediaType": "application/vnd.oci.image.manifest.v1+json",
  "artifactType": "application/vnd.docker.attestation.manifest.v1+json",
  "config": {
    "mediaType": "application/vnd.oci.empty.v1+json",
    "digest": "sha256:44136fa355b3678a1146ad16f7e8649e94fb4fc21fe77e8310c060f61caaff8a",
    "size": 2,
    "data": "e30="
  },
  "layers": [
    {
      "mediaType": "application/vnd.in-toto+json",
      "digest": "sha256:60d4368f1cf8af22d71e03b94722edb4bba4ba43a4d91d6dbb078f6f08778272",
      "size": 25721,
      "annotations": {
        "in-toto.io/predicate-type": "https://slsa.dev/provenance/v1"
      }
    }
  ],
  "subject": {
    "mediaType": "application/vnd.oci.image.manifest.v1+json",
    "digest": "sha256:b77a52f633912784b42e5ae79ac4688d12c769c838f27a9342d3f2b6af3a67c7",
    "size": 1056
  }
}