# OCI Ancestry Extraction

## Module
Scanner

## Status
VERIFIED

## Description
Extract base image references from OCI manifest config.history to populate lineage parent relationships.

## Implementation Details
- **Ancestry Extractor**:
  - `src/Scanner/__Libraries/StellaOps.Scanner.Storage.Oci/IOciAncestryExtractor.cs` - `IOciAncestryExtractor` interface defining the ancestry extraction contract
  - `src/Scanner/__Libraries/StellaOps.Scanner.Storage.Oci/OciAncestryExtractor.cs` - `OciAncestryExtractor` extracts base image references from OCI manifest config.history to populate lineage parent relationships
- **Layer Dependency Graph**:
  - `src/Scanner/__Libraries/StellaOps.Scanner.Core/Models/LayerDependencyGraph.cs` - `LayerDependencyGraph` models parent-child layer relationships from ancestry data

## E2E Test Plan
- [ ] Scan a container image built from a known base image and verify the OCI ancestry extractor identifies the base image reference from config.history
- [ ] Verify lineage parent relationships are populated correctly linking child image to base image
- [ ] Verify multi-stage build ancestry is correctly resolved (identifying intermediate build stages)
- [ ] Verify images with `LABEL` or `org.opencontainers.image.base.name` annotations use those for ancestry when available
- [ ] Verify images without config.history (scratch-based) are handled gracefully with no parent relationship

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## Verification

| Check | Result |
|-------|--------|
| Tier 0 - Source files exist | PASS |
| Tier 1 - Build + code review | PASS |
| Tier 2 - Integration tests | PASS |
| Verified | 2026-02-13T18:10:00Z |