# RPM Legacy BDB Packages Database Fallback

## Module
Scanner

## Status
IMPLEMENTED

## Description
Adds fallback support for legacy Berkeley DB (BDB) format RPM package databases alongside the modern SQLite format, enabling package discovery on older RHEL/CentOS images.

## Implementation Details
- **Berkeley DB Reader**:
  - `src/Scanner/__Libraries/StellaOps.Scanner.Analyzers.OS.Rpm/Internal/BerkeleyDbReader.cs` - `BerkeleyDbReader` parses legacy BDB format RPM package databases for older RHEL/CentOS images
- **RPM Database Reader**:
  - `src/Scanner/__Libraries/StellaOps.Scanner.Analyzers.OS.Rpm/RpmDatabaseReader.cs` - `RpmDatabaseReader` with fallback logic: tries modern SQLite format first, falls back to BDB format for legacy images

## E2E Test Plan
- [ ] Scan an older RHEL/CentOS image (pre-RHEL 8) using BDB format RPM database and verify packages are discovered
- [ ] Scan a modern RHEL/CentOS image using SQLite format RPM database and verify it uses the primary path
- [ ] Verify the fallback logic correctly detects the database format and chooses the appropriate reader
- [ ] Verify BDB-parsed packages include correct name, version, release, and architecture metadata
- [ ] Verify both BDB and SQLite paths produce consistent package lists for the same set of installed packages