Requirements:
- Private registry for ML container images (large layers, GPU libs)
- Fine-grained authZ, auditability, vulnerability scanning, lifecycle/retention, cross-region availability, CI/CD integration
High-level architecture:
CI/CD → Private Registry (managed: AWS ECR / JFrog Artifactory / Nexus) fronted by API Gateway + ALB → Storage backend (S3/Blob with versioning) → Replication service → Vulnerability scanner + Audit logs → Monitoring & cleanup worker
Components & choices:
- Authentication/Authorization: Use enterprise SSO (OIDC/SAML) integrated with IAM. For AWS ECR, map IAM roles to repositories and use resource-based policies. For Artifactory, connect to LDAP/SAML and use groups + repository-per-team + permission targets. Enforce least privilege, MFA for push permissions, and short-lived tokens (STS).
- Storage backend: Object store (S3/MinIO/Azure Blob) with lifecycle rules and encryption at rest (KMS). Enable multipart uploads and delta layer deduplication.
- Retention & cleanup: Enforce immutability for prod tags (write-once), retention policy for dev images (e.g., keep last N builds or 30 days). Implement garbage collection using registry GC or S3 lifecycle; tag images with metadata (owner, pipeline, expiry). Provide a cleanup service that cross-checks deployed manifests before deletion.
- Vulnerability scanning: Integrate scanning in CI pipeline (Trivy/Clair/Anchore) on build and push; block promotion to prod on critical CVEs. Run periodic registry scans for newly discovered CVEs and create automated MR/alerts. Store SBOMs (CycloneDX) alongside images.
- Replication & availability: Use registry-native cross-region replication (ECR cross‑region replication or Artifactory Xray + replication). Replicate image manifests and blobs to regional S3 buckets, ensure consistency with async replication and health checks. Use global DNS + regional gateways for low-latency pulls; fall back to other regions on failures.
- Auditing, monitoring & secrets: Centralized logs (CloudWatch/ELK) for push/pull/audit events, alert on anomalous patterns. Rotate credentials and use secrets manager for registry tokens. Enforce TLS, image signing (cosign/notary) for provenance.
Trade-offs:
- Managed service (ECR) reduces ops but ties to cloud; Artifactory is feature-rich (replication, permission granularity, metadata) but heavier to operate.
- Strong immutability and scanning increases latency in CI but improves security.
This design ensures secure, scalable hosting of ML images with governance, automated cleanup, vulnerability management, and cross-region resilience.
