ostree container image deploy: support platform variant

[rriemann]

Some old x86_64 devices require variant "v2" to be set explicitly with images defaulting to "v3".

I make such images with:

bluebuild build -vv -S sigstore --platform linux/amd64/v2 --push ./recipes/$RECIPE

Unfortunately, this breaks ostree:

This is the skopeo output:

skopeo inspect --raw docker://registry.gitlab.com/eu-os/workspace-images/eu-os-base-demo/eu-os-demo:latest
{
  "schemaVersion": 2,
  "mediaType": "application/vnd.oci.image.index.v1+json",
  "manifests": [
    {
      "mediaType": "application/vnd.oci.image.manifest.v1+json",
      "digest": "sha256:45b6d9b0aeb1eb149dae0b6d6d3a446ea20d8a47d67df6aa6fc7cbca29d97f75",
      "size": 22226,
      "platform": {
        "architecture": "amd64",
        "os": "linux",
        "variant": "v2"
      }
    },
    {
      "mediaType": "application/vnd.oci.image.manifest.v1+json",
      "digest": "sha256:ce197c50c59a449e9ad11f7111ac92db84fdeca190138909b7ff334546a00334",
      "size": 566,
      "annotations": {
        "vnd.docker.reference.digest": "sha256:45b6d9b0aeb1eb149dae0b6d6d3a446ea20d8a47d67df6aa6fc7cbca29d97f75",
        "vnd.docker.reference.type": "attestation-manifest"
      },
      "platform": {
        "architecture": "unknown",
        "os": "unknown"
      }
    }
  ]
}⏎          

Can we please add a way to configure variant and document it for both ostree and bootc?

[cgwalters]

Does skopeo inspect -n docker://<image> also work on this target device? The bootc/ostree backend is just reusing core skopeo logic (albeit via the image proxy) and should resolve multi-arch manifests in exactly the same way.

(Don't use --raw for this test, which will always just give the raw multi-arch manifest and not follow per arch)

[rriemann]

Hi @cgwalters ,

the container registry is from foreman. The anaconda installer environment has ostree and bootc (fedora 42), but no skopeo. Hence, I call skopeo from an almalinux computer.

The call here below is from when I imported already an image to foreman built without "--platform linux/amd64/v2". This is why no variant is in here.

$ skopeo inspect -n docker://fleet.eu-os.internal/public_organisation/eu_os/demo
{
    "Name": "fleet.eu-os.internal/public_organisation/eu_os/demo",
    "Digest": "sha256:a12ecea9406718126a66c3dca843c4c28941620c22f421dfd60c9f40827cf3ad",
    "RepoTags": [],
    "Created": "2025-11-24T11:29:48.427799721Z",
    "DockerVersion": "",
    "Labels": {
        "containers.bootc": "1",
        "io.artifacthub.package.logo-url": "https://avatars.githubusercontent.com/u/120078124?s=200\u0026v=4",
        "io.artifacthub.package.readme-url": "https://raw.githubusercontent.com/blue-build/cli/main/README.md",
        "io.buildah.version": "1.33.7",
        "org.blue-build.build-id": "59a8c430-fe72-4c77-91ce-8d8d780847b8",
        "org.opencontainers.image.base.digest": "sha256:40a4a5b0482be48ea82457094f2bd4878e7587b92d0555b2c2b0b12db67b338a",
        "org.opencontainers.image.base.name": "ghcr.io/ublue-os/kinoite-main:42",
        "org.opencontainers.image.created": "2025-11-24T11:22:32.742897354+00:00",
        "org.opencontainers.image.description": "Demo base image for EU OS. EU OS is a Proof-of-Concept for the deloyment of a Fedora-based Linux operating system with a KDE Plasma desktop environment in a typical public sector organisation.",
        "org.opencontainers.image.source": "https://gitlab.com/eu-os/workspace-images/eu-os-base-demo",
        "org.opencontainers.image.title": "eu-os-demo",
        "org.opencontainers.image.version": "42.20251124.1",
        "ostree.bootable": "true",
        "ostree.commit": "e38bc91c19289f3cfa92bbae3488ea447922ef25659a85461a965334c77f61b8",
        "ostree.final-diffid": "sha256:12787d84fa137cd5649a9005efe98ec9d05ea46245fdc50aecb7dd007f2035b1",
        "ostree.linux": "6.17.8-200.fc42.x86_64",
        "quay.expires-after": "4w",
        "rpmostree.inputhash": "bdc794ecdd621c5d124382c149fe80f16131e0ac96bfd0c4893aea302053e23b"
    },
    "Architecture": "amd64",
    "Os": "linux",
    "Layers": [
        "sha256:c900bc46a1b0c65a193bcdf51760641f0d281660f93f6e9b62e61be429f26964",
        "sha256:efe7fffb3151d34de9837ab15c1428dd8c0b78fd96b5e32a95424ef67aa5ecd2",
        "redacted....",
        "sha256:e4eb52992aeb18e038be8d938e6485b0bd286a5bd6c47ea88dcd06903973d01f"
    ],
    "LayersData": [
        {
            "MIMEType": "application/vnd.oci.image.layer.v1.tar+gzip",
            "Digest": "sha256:c900bc46a1b0c65a193bcdf51760641f0d281660f93f6e9b62e61be429f26964",
            "Size": 8738014,
            "Annotations": null
        },
        {
            "redacted": true
        },
    ],
    "Env": [
        "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
    ]
}