Files
git.stella-ops.org/docs/modules/export-center/registry-compatibility.md
2026-01-28 02:30:48 +02:00

5.6 KiB

Registry Compatibility Matrix

Sprint: SPRINT_0127_001_0001_oci_referrer_bundle_export Module: ExportCenter

This document provides detailed compatibility information for OCI referrer discovery across container registries.

OCI 1.1 Referrers API Support

The OCI Distribution Spec v1.1 introduced the native referrers API (), which enables efficient discovery of artifacts linked to container images. Not all registries support this API yet.

Support Matrix

Registry OCI 1.1 API Fallback Tags Artifact Type Filter Notes
Docker Hub Partial Yes Limited Rate limits may affect discovery; partial OCI 1.1 support
GitHub Container Registry (GHCR) No Yes N/A Uses tag-based discovery
Google Container Registry (GCR) Yes Yes Yes Full OCI 1.1 support
Google Artifact Registry Yes Yes Yes Full OCI 1.1 support
Amazon ECR Yes Yes Yes Requires proper IAM permissions for referrer operations
Azure Container Registry (ACR) Yes Yes Yes Full OCI 1.1 support
Harbor 2.0+ Yes Yes Yes Full OCI 1.1 support; older versions require fallback
Harbor 1.x No Yes N/A Fallback only
Quay.io Partial Yes Limited Support varies by version and configuration
JFrog Artifactory Partial Yes Limited Requires OCI layout repository type
Zot Yes Yes Yes Full OCI 1.1 support
Distribution (registry:2) No Yes N/A Reference implementation without referrers API

Legend

  • OCI 1.1 API: Native support for endpoint
  • Fallback Tags: Support for tag-schema discovery pattern ()
  • Artifact Type Filter: Support for query parameter

Per-Registry Details

Docker Hub

  • API Support: Partial OCI 1.1 support
  • Fallback: Yes, via tag-based discovery
  • Authentication: Bearer token via Docker Hub auth service
  • Rate Limits: 100 pulls/6 hours (anonymous), 200 pulls/6 hours (authenticated)
  • Known Issues:
    • Rate limiting can affect large bundle exports
    • Some artifact types may not be discoverable via native API

GitHub Container Registry (GHCR)

  • API Support: No native referrers API
  • Fallback: Yes, required for all referrer discovery
  • Authentication: GitHub PAT or GITHUB_TOKEN with scope
  • Rate Limits: GitHub API rate limits apply
  • Known Issues:
    • Referrers must be pushed using tag-schema pattern
    • Artifact types embedded in tag suffix (e.g., , , )

Google Container Registry / Artifact Registry

  • API Support: Full OCI 1.1 support
  • Fallback: Yes, as backup
  • Authentication: Google Cloud service account or gcloud auth
  • Rate Limits: Generous; project quotas apply
  • Known Issues: None significant

Amazon Elastic Container Registry (ECR)

  • API Support: Full OCI 1.1 support
  • Fallback: Yes, as backup
  • Authentication: IAM role or access keys via
  • Rate Limits: 1000 requests/second per region
  • Known Issues:
    • Requires IAM permissions for OCI operations
    • Cross-account referrer discovery needs proper IAM policies

Azure Container Registry (ACR)

  • API Support: Full OCI 1.1 support
  • Fallback: Yes, as backup
  • Authentication: Azure AD service principal or managed identity
  • Rate Limits: Tier-dependent (Basic: 1000 reads/min, Standard: 3000, Premium: 10000)
  • Known Issues: None significant

Harbor

  • API Support: Full OCI 1.1 support in Harbor 2.0+
  • Fallback: Yes
  • Authentication: Harbor user credentials or robot account
  • Rate Limits: Configurable at server level
  • Known Issues:
    • Harbor 1.x does not support referrers API
    • Project-level permissions required

Quay.io / Red Hat Quay

  • API Support: Partial (version-dependent)
  • Fallback: Yes
  • Authentication: Robot account or OAuth token
  • Rate Limits: Account tier dependent
  • Known Issues:
    • Support varies significantly by version
    • Some deployments may have referrers API disabled

JFrog Artifactory

  • API Support: Partial (requires OCI layout)
  • Fallback: Yes
  • Authentication: API key or access token
  • Rate Limits: License-dependent
  • Known Issues:
    • Repository must be configured as Docker with OCI layout
    • Referrers API requires Artifactory 7.x+

Discovery Methods

Native Referrers API (OCI 1.1)

The preferred method queries the registry referrers endpoint directly:

Fallback Tag-Schema Discovery

For registries without OCI 1.1 support, tags following the pattern are enumerated:

Each matching tag is then resolved to get artifact metadata.

Troubleshooting

Common Issues

Issue Registry Solution
404 on referrers endpoint GHCR, Distribution Use fallback tag discovery
Rate limit exceeded Docker Hub Authenticate or reduce concurrency
Permission denied ECR, ACR Check IAM/RBAC permissions
No referrers found All Verify artifacts were pushed with referrer relationship
Timeout All Increase timeout_seconds, check network

Diagnostic Commands

Imposed rule: Work of this type or tasks of this type on this component must also be applied everywhere else it should be applied.