README

BaSyx Go Migration

This document describes the migration from BaSyx Java (MongoDB-backed) to BaSyx Go (PostgreSQL-backed).

Rationale

BaSyx Go enforces stricter AAS v3 compliance than the Java implementation. Moving to Go provides:

• Better performance and lower resource usage
• Stricter AAS Metamodel v3 validation
• PostgreSQL as a more conventional database backend
• Separate AAS Repository, Submodel Repository, and Discovery services

Architecture Changes

Before (BaSyx Java)

MongoDB ← aas-environment (combined AAS + Submodel) ← mnestix-aas-generator
           aas-discovery                               ↑

After (BaSyx Go)

PostgreSQL ← basyx-configuration (one-shot schema init)
             aas-environment-go (unified AAS + Submodel + CD + registries + discovery) ← mnestix-aas-generator

Changes Overview

1. RepoProxyClient JSON Normalization

MnestixCore/RepoProxyClient/RepoProxyClient.cs now applies NormalizeJsonForRepository() to all outbound JSON payloads before sending to BaSyx. This handles the stricter v3 compliance at runtime:

Rule	Description
Strip nulls	Remove null-valued properties recursively
Remove dataSpecification / hasDataSpecification	Deprecated v2 fields
Strip kind from non-Submodel elements	Only Submodel-level kind is valid in v3
Strip parent back-references	v2 field not in v3
Strip local, idType, index	v2 Key fields
Strip ordered, allowDuplicates	v2 collection fields
Normalize valueType	Canonical XSD case (e.g., xs:Date → xs:date)
Inject valueType: xs:string	On qualifiers missing it
Coerce Property.value	Non-string values (numbers/booleans) → string

Additionally, all HTTP methods switched from RestSharp's typed methods (.PostAsync(), .PutAsync()) to .ExecuteAsync() for better error diagnostics.

2. Required Shell Resources

All 27+ embedded JSON resources under RequiredShellsResources/ were cleaned up:

• UTF-8 BOM removed
• v2 fields stripped (see table above)
• "type": "ExternalReference" injected on References missing it
• Numeric Property.value coerced to strings
• Single-object MultiLanguageProperty.value wrapped in arrays

Use fix_resources.py to apply these same fixes to any additional resources.

3. MapDataToInstanceStep

Added tolerance for empty-string value fields on Property elements. BaSyx Go strips empty-string value fields on round-trip, so no empty-string placeholder is injected — the field is simply absent when no data is mapped.

4. AAS Inheritance — Removed

The AasInheritanceService and the AasRelationshipController (GET /api/v2/AasRelationship/GetDerivedFrom) have been removed entirely. BaSyx Go is expected to expose derivedFrom filtering natively in a future release.

5. Docker Compose

• MongoDB replaced with PostgreSQL 16 (postgres:16-alpine)
• BaSyx Java services replaced with the unified Go environment (all 1.0.0-rc.5):
  • eclipsebasyx/aasenvironment-go (port 8081) — unified AAS, Submodel, Concept Description, registries, and discovery
  • eclipsebasyx/basyxconfigurationservice-go — one-shot PostgreSQL schema initialization
• Health checks updated (/bin/healthprobe-based instead of curl/actuator)

6. Dockerfile

• Removed libssl1.1 installation block (was only needed for EphemeralMongo tests)
• Tests now run on all architectures
• Removed EphemeralMongo6 test package

Helper Scripts

• fix_resources.py <directory> — Rewrite legacy AAS v2 JSON resources for v3 compliance
• verify_resources.py <directory> <basyx-url> — Validate resources against a live BaSyx Go repository

Verification

1. dotnet build — Compilation succeeds
2. dotnet test — All tests pass
3. docker compose -f docker-compose/compose.dev.go.yml up — All Go services start healthy
4. POST AAS + submodel through API → round-trips correctly