711 lines
36 KiB
Markdown
711 lines
36 KiB
Markdown
# Aegis — Deep Architectural Analysis
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> **Author:** Automated architecture review
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> **Date:** February 11, 2026 (updated February 19, 2026)
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> **Scope:** Backend (FastAPI/Python), Frontend (React/TypeScript), Infrastructure (Docker)
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>
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> **Note:** Sections marked with ✅ reflect changes implemented since the initial analysis.
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---
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## Table of Contents
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1. [Current Architecture](#1-current-architecture)
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2. [Coupling Analysis](#2-coupling-analysis)
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3. [Business Logic vs Infrastructure Separation](#3-business-logic-vs-infrastructure-separation)
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4. [SOLID Evaluation](#4-solid-evaluation)
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5. [Architectural Risks](#5-architectural-risks)
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6. [Refactor Proposal Towards Clean Architecture](#6-refactor-proposal-towards-clean-architecture)
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7. [Executive Summary](#7-executive-summary)
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---
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## 1. Current Architecture
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### 1.1. Classification: Layered Monolith with Incomplete Service Layer
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Aegis follows a **layered monolithic architecture** deployed as two containers (backend + frontend) with a **partial and inconsistent** level of separation. It is not Clean Architecture, nor Hexagonal, nor microservices.
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```
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┌─────────────────────────────────────────────────┐
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│ FRONTEND │
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│ React 19 + TypeScript + Vite │
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│ ┌──────────┐ ┌──────────┐ ┌───────────────┐ │
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│ │ Pages │→ │ API Layer│→ │ Axios Client │ │
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│ │(21 pages)│ │(22 mods) │ │(HttpOnly JWT) │ │
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│ └──────────┘ └──────────┘ └───────────────┘ │
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└────────────────────────┬────────────────────────┘
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│ HTTP/REST
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┌────────────────────────▼────────────────────────┐
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│ BACKEND │
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│ FastAPI + SQLAlchemy │
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│ │
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│ ┌─────────────────────────────────────────────┐ │
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│ │ Router Layer (21 routers) │ │
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│ │ Contains: validation, queries, partial │ │
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│ │ business logic, serialization, auditing │ │
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│ └────────┬──────────────────┬─────────────────┘ │
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│ │ │ │
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│ ┌────────▼───────┐ ┌──────▼──────────────────┐ │
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│ │ Service Layer │ │ Direct DB Access │ │
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│ │ (20 services) │ │ (SQLAlchemy queries │ │
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│ │ Partial: only │ │ inside routers) │ │
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│ │ for workflows │ │ │ │
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│ └────────┬───────┘ └──────┬──────────────────┘ │
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│ │ │ │
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│ ┌────────▼──────────────────▼─────────────────┐ │
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│ │ Model Layer (18 models) │ │
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│ │ SQLAlchemy ORM — Anemic Domain Models │ │
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│ └────────────────────┬────────────────────────┘ │
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│ │ │
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│ ┌────────────────────▼────────────────────────┐ │
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│ │ Database Layer │ │
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│ │ PostgreSQL + MinIO (evidence storage) │ │
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│ └─────────────────────────────────────────────┘ │
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└──────────────────────────────────────────────────┘
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```
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### 1.2. Actual Distribution of Responsibilities
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| Layer | Files | Actual Responsibility |
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|-------|-------|----------------------|
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| **Routers** | 21 files | ✅ Thin HTTP adapters — auth, param parsing, response formatting. Delegate to services. |
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| **Services** | 30+ files | ✅ All business logic, query orchestration, domain validation. Framework-agnostic. |
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| **Domain** | 8+ files | ✅ Pure entities, value objects, ports, errors. Zero framework imports. |
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| **Infrastructure** | 5+ files | ✅ Repository implementations, Redis client, mappers. |
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| **Models** | 19 files | ORM table definitions — persistence mapping only |
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| **Schemas** | 10 files | Pydantic DTOs for request/response |
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| **Database** | 1 file | Session factory and `get_db()` generator |
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### 1.3. ✅ Consistent Delegation Pattern (was: Two Coexisting Patterns)
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**Update (Feb 19):** The "split architectural personality" has been resolved. All major routers now follow the same pattern:
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**Pattern — Router-delegates-to-Service:**
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Routers are thin HTTP adapters that parse parameters, authenticate, and delegate to framework-agnostic services:
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```python
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# threat_actors.py — thin adapter, all logic in service
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@router.get("/{actor_id}")
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def get_threat_actor(actor_id: str, db=Depends(get_db), current_user=Depends(get_current_user)):
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return get_actor_detail(db, actor_id)
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```
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Extracted services: `coverage_report_service`, `metrics_query_service`, `compliance_service`, `detection_rule_service`, `threat_actor_service`, `test_crud_service`, `evidence_service`, `campaign_crud_service`, `scoring_config_service`.
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**Remaining:** `users.py`, `audit.py`, `data_sources.py`, `heatmap.py` still have direct queries. These are lower priority since they are simpler or already partially extracted.
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---
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## 2. Coupling Analysis
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### 2.1. Coupling Matrix
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```
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Routers Services Models Database Schemas Config
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Routers — MEDIUM HIGH HIGH HIGH LOW
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Services LOW — HIGH HIGH NONE MEDIUM
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Models NONE NONE — HIGH NONE NONE
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Schemas NONE NONE LOW — NONE NONE
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Database NONE NONE NONE — NONE LOW
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```
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### 2.2. Router ↔ Model — ✅ LARGELY RESOLVED (was HIGH COUPLING)
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**Update (Feb 19):** Most routers no longer import ORM models or execute queries directly. Only **4 out of 21 routers** still have direct DB access:
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| Router | Status | Detail |
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|--------|--------|--------|
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| `techniques.py` | ✅ Extracted | Uses `SATechniqueRepository` via dependency injection |
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| `reports.py` | ✅ Extracted | Delegates to `coverage_report_service` |
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| `metrics.py` | ✅ Extracted | Delegates to `metrics_query_service` |
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| `compliance.py` | ✅ Extracted | Delegates to `compliance_service` |
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| `detection_rules.py` | ✅ Extracted | Delegates to `detection_rule_service` |
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| `threat_actors.py` | ✅ Extracted | Delegates to `threat_actor_service` |
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| `tests.py` | ✅ Extracted | Delegates to `test_crud_service` + `test_workflow_service` |
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| `evidence.py` | ✅ Extracted | Delegates to `evidence_service` |
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| `campaigns.py` | ✅ Extracted | Delegates to `campaign_crud_service` |
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| `users.py` | Remaining | Direct queries (simple CRUD) |
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| `audit.py` | Remaining | Direct queries (read-only list) |
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| `data_sources.py` | Remaining | Direct queries |
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| `heatmap.py` | Remaining | Complex queries (partially extracted via `heatmap_service`) |
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### 2.3. Router ↔ Database — HIGH COUPLING
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All routers receive `db: Session = Depends(get_db)` and operate with the SQLAlchemy session directly. This means:
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- Routers know the ORM (`db.query`, `db.add`, `db.commit`, `joinedload`)
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- Routers handle transactions implicitly
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- There is no persistence abstraction — migrating from SQLAlchemy to another ORM or raw queries would require rewriting **all** routers
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### 2.4. Service ↔ Model/Database — HIGH COUPLING
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Services also access SQLAlchemy directly:
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```python
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# scoring_service.py
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all_tests = db.query(Test).filter(Test.technique_id == technique.id).all()
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# notification_service.py
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notif = db.query(Notification).filter(...).first()
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```
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Services do not use repositories or abstractions — they are essentially functions that orchestrate queries and logic.
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### 2.5. Service ↔ Service — MEDIUM COUPLING
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Inter-service coupling exists:
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- `test_workflow_service` → `audit_service` + `notification_service`
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- `scoring_service` reads from `settings` directly (mutable global config)
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- `campaign_scheduler_service` → `campaign_service`
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There is no dependency injection between services — everything is direct imports.
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### 2.6. Service ↔ Framework — ✅ RESOLVED (was HIGH COUPLING)
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~~Domain services import `HTTPException` from FastAPI.~~
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**Update (Feb 18):** `test_workflow_service.py` now raises domain exceptions (`InvalidOperationError`, `InvalidStateTransition`) from `app.domain.exceptions`. The `middleware/error_handler.py` maps these to HTTP responses automatically. Services no longer import `HTTPException`.
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```python
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# Current: domain/errors.py exceptions mapped by middleware
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raise InvalidStateTransition(current_state=..., target_state=..., entity_type="Test")
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# middleware/error_handler.py → 400 Bad Request automatically
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```
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### 2.7. Frontend ↔ Backend — LOW COUPLING (Correct)
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Communication is via REST API with aligned but independent types (`types/models.ts` vs `schemas/*.py`). The frontend uses Axios with interceptors — good decoupling.
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---
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## 3. Business Logic vs Infrastructure Separation
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### 3.1. Diagnosis: ✅ MOSTLY RESOLVED (was INSUFFICIENT SEPARATION)
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**Update (Feb 19):** All major routers have been refactored to delegate to framework-agnostic services.
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| Aspect | Status | Detail |
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|--------|--------|--------|
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| **Workflow logic** | ✅ WELL SEPARATED | `test_workflow_service.py` encapsulates the state machine with domain exceptions |
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| **Scoring** | ✅ WELL SEPARATED | `scoring_service.py` reads weights from DB via `scoring_config_service.py` (no more mutable global state) |
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| **Test CRUD** | ✅ SEPARATED | `test_crud_service.py` handles all CRUD, validation, and permission checks with domain exceptions |
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| **Report generation** | ✅ SEPARATED | `coverage_report_service.py` handles query aggregation and CSV building (N+1 fixed) |
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| **Metrics** | ✅ SEPARATED | `metrics_query_service.py` handles dashboard aggregation queries |
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| **Compliance** | ✅ SEPARATED | `compliance_service.py` handles framework analysis and gap detection |
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| **Detection rules** | ✅ SEPARATED | `detection_rule_service.py` handles queries, auto-association, and evaluation |
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| **Threat actors** | ✅ SEPARATED | `threat_actor_service.py` handles queries, coverage, and gap analysis (N+1 fixed) |
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| **Evidence** | ✅ SEPARATED | `evidence_service.py` handles permission validation and queries with domain exceptions |
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| **Campaigns** | ✅ SEPARATED | `campaign_crud_service.py` handles CRUD, lifecycle, and scheduling |
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| **Heatmap/visualization** | PARTIAL | `heatmap_service.py` exists but router still has some logic |
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| **Data import** | WELL SEPARATED | The 8 import services are correctly isolated |
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| **Notifications** | WELL SEPARATED | `notification_service.py` encapsulates all logic |
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| **Auditing** | WELL SEPARATED | `audit_service.py` is a pure `log_action()` function |
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### 3.2. Anemic Model (Anti-pattern)
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SQLAlchemy models are purely declarative — they have no business methods:
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```python
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# models/test.py — columns only, zero behavior
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class Test(Base):
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__tablename__ = "tests"
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id = Column(UUID, primary_key=True)
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state = Column(Enum(TestState))
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# ... more columns
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# Missing: can_transition(), validate(), calculate_score()
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```
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Logic that should be in domain models (business validations, state transitions, calculations) is scattered across routers and services.
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### 3.3. Infrastructure Bleeding Into Logic
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| Infrastructure | Where It Appears Inappropriately |
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|---------------|--------------------------------|
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| `SQLAlchemy Session` | Inside domain services (scoring, workflow, notifications) |
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| `FastAPI HTTPException` | Inside domain services (test_workflow_service) |
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| `MinIO/boto3` | `storage.py` is well isolated, but called from routers directly |
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| `APScheduler` | Directly coupled in `jobs/mitre_sync_job.py` with `SessionLocal()` |
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---
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## 4. SOLID Evaluation
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### 4.1. Single Responsibility Principle (SRP) — ✅ MOSTLY COMPLIANT (was PARTIAL VIOLATION)
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**Update (Feb 19):** Fat routers have been slimmed. Each router is now a thin HTTP adapter.
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| Component | Compliant? | Detail |
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|-----------|-----------|-------|
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| `heatmap.py` (router) | PARTIAL | Still has some inline logic; `heatmap_service` exists but not fully extracted |
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| `reports.py` (router) | ✅ YES | Thin adapter → `coverage_report_service` |
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| `tests.py` (router) | ✅ YES | Thin adapter → `test_crud_service` + `test_workflow_service` |
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| `campaigns.py` (router) | ✅ YES | Thin adapter → `campaign_crud_service` |
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| `evidence.py` (router) | ✅ YES | Thin adapter → `evidence_service` |
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| `scoring_service.py` | ✅ YES | Reads weights from `scoring_config_service` (DB-backed, not mutable settings) |
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| `test_workflow_service.py` | ✅ YES | Single responsibility: test state machine |
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| `notification_service.py` | ✅ YES | Single responsibility: notification management |
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| `audit_service.py` | ✅ YES | Single responsibility: audit logging |
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**Verdict:** All major routers now comply with SRP. Only `heatmap.py` and a few minor routers have remaining inline logic.
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### 4.2. Open/Closed Principle (OCP) — ✅ PARTIALLY RESOLVED (was VIOLATION)
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**Update (Feb 19):**
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- **Scoring weights:** ✅ Resolved — Weights are now persisted in the `scoring_config` DB table via `scoring_config_service.py`. The `ScoringWeights` value object validates invariants (sum = 100, non-negative). No more mutable global `settings`.
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- **Heatmap layers:** Each heatmap type is a separate endpoint with hardcoded logic. Adding a new layer type requires modifying the router.
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- **Import services:** Each data source is a separate service without a common interface. Adding a new source requires creating a new service AND modifying `data_sources.py` and `system.py`.
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- **Test states:** The state machine is well defined in `VALID_TRANSITIONS`, but adding a new state requires modifying the dictionary AND potentially all services that read `TestState`.
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### 4.3. Liskov Substitution Principle (LSP) — N/A (Partial)
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There is no significant inheritance or polymorphism in the backend. Services are functions, not classes. There are no interfaces or abstract classes. **Does not directly apply**, but the absence of formal contracts (protocols/ABCs) is a symptom of not being designed for extensibility.
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### 4.4. Interface Segregation Principle (ISP) — ✅ PARTIALLY RESOLVED (was VIOLATION)
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**Update (Feb 19):**
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- ✅ Protocol interfaces exist for `TechniqueRepository` and `TestRepository` in `domain/ports/repositories/`.
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- Services expose focused functions per module (e.g., `threat_actor_service` exposes 4 functions, each for one use case).
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- The `Settings` object is still monolithic but scoring weights have been extracted to a dedicated DB table with a focused service interface.
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### 4.5. Dependency Inversion Principle (DIP) — ✅ PARTIALLY RESOLVED (was SEVERE VIOLATION)
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**Update (Feb 18):** Protocol interfaces and abstractions now exist:
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```python
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# domain/ports/repositories/ — Protocol interfaces
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class TechniqueRepository(Protocol):
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def find_by_id(self, technique_id: UUID) -> TechniqueEntity | None: ...
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def save(self, technique: TechniqueEntity) -> TechniqueEntity: ...
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# dependencies/repositories.py — FastAPI Depends() wiring
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def get_technique_repository(db=Depends(get_db)) -> SATechniqueRepository: ...
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```
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- **Domain layer** has zero framework imports (no FastAPI, no SQLAlchemy).
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- **Repository ports** define contracts; infrastructure implements them.
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- `test_workflow_service.py` now uses domain exceptions instead of `HTTPException`.
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- `UnitOfWork` manages transactions.
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**Remaining:** Some services still use direct imports for `audit_service`, `notification_service`. Full DIP adoption is incremental.
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---
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## 5. Architectural Risks
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### 5.1. ✅ RESOLVED: God Routers (was CRITICAL RISK)
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**Update (Feb 19):** All critical "fat routers" have been refactored to thin HTTP adapters:
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| Router | Before | After | Service |
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|--------|--------|-------|---------|
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| `tests.py` | 664 lines | ~300 lines (workflow endpoints unchanged) | `test_crud_service.py` |
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| `campaigns.py` | ~400+ lines | ~200 lines | `campaign_crud_service.py` |
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| `reports.py` | 273 lines | ~100 lines | `coverage_report_service.py` |
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| `compliance.py` | ~350+ lines | ~100 lines | `compliance_service.py` |
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| `metrics.py` | ~250 lines | ~80 lines | `metrics_query_service.py` |
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| `detection_rules.py` | 374 lines | ~130 lines | `detection_rule_service.py` |
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| `threat_actors.py` | 312 lines | ~100 lines | `threat_actor_service.py` |
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| `evidence.py` | 367 lines | ~200 lines | `evidence_service.py` |
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**Remaining:** `heatmap.py` still has inline logic (~528 lines). Lower priority since it's already partially extracted to `heatmap_service`.
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### 5.2. ~~CRITICAL RISK: In-Memory Token Blacklist~~ ✅ RESOLVED
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**Update (Feb 18):** The token blacklist is now Redis-backed via `infrastructure/redis_client.py`. Tokens are stored with TTL matching expiration. Shared across all workers and survives restarts.
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### 5.3. ✅ RESOLVED: Mutable Settings at Runtime (was HIGH RISK)
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**Update (Feb 19):** Scoring weights are now persisted in the `scoring_config` database table via `scoring_config_service.py`. The `PATCH /scores/config` endpoint writes to the DB instead of mutating the `settings` object. The `ScoringWeights` value object validates that weights sum to 100 and are non-negative.
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```python
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# scoring_config_service.py — DB-backed, validated, persistent
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def update_scoring_weights(db: Session, *, tests=None, ...) -> dict:
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new = ScoringWeights(tests=..., ...) # validates invariants
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row = db.query(ScoringConfig).first()
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...
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db.commit()
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```
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- ✅ Changes survive restarts (persisted in DB)
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- ✅ Thread-safe (DB transactions)
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- ✅ Validated via `ScoringWeights` value object
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- Falls back to env-var defaults when no DB row exists
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### 5.4. ~~HIGH RISK: No Repository Layer~~ ✅ PARTIALLY RESOLVED
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**Update (Feb 18):** Repository ports and implementations now exist:
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- `domain/ports/repositories/` — Protocol interfaces for `TechniqueRepository` and `TestRepository`.
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- `infrastructure/persistence/repositories/` — SQLAlchemy implementations (`SATechniqueRepository`, `SATestRepository`) with batch query methods.
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- `dependencies/repositories.py` — FastAPI `Depends()` wiring.
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**Remaining:** Old routers still use direct `db.query()`. Migration is incremental — new endpoints use repositories, old ones coexist.
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### 5.5. ~~HIGH RISK: No CI/CD~~ ✅ RESOLVED
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**Update (Feb 18):** GitHub Actions CI pipeline exists at `.github/workflows/ci.yml`:
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- Runs `ruff` lint + `pytest` on every push/PR.
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- Uses PostgreSQL + Redis service containers (production-like environment).
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- Local validation via `scripts/agent_validate_backend.sh`.
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### 5.6. MEDIUM RISK: Background Jobs with Own Sessions (partially mitigated)
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```python
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# mitre_sync_job.py
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db = SessionLocal()
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try:
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sync_mitre(db)
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finally:
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db.close()
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```
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Background jobs create sessions outside the request lifecycle. This is technically correct, but:
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- No robust error handling (no retry mechanism).
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- ✅ Structured JSON logging now available (`logging_config.py`)
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- No dead letter queue for failed jobs.
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### 5.7. ~~MEDIUM RISK: Anemic Models~~ ✅ PARTIALLY RESOLVED
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**Update (Feb 18):** Rich domain entities now exist alongside ORM models:
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- `domain/test_entity.py` — Full state machine with business logic, domain events, dual validation, timers.
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- `domain/entities/technique.py` — Status recalculation, review lifecycle, MITRE ID validation.
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- `domain/value_objects/` — `MitreId`, `ScoringWeights` (immutable, validated).
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- ORM models remain anemic by design (persistence mapping only). Business logic lives in domain entities.
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**Remaining:** Campaign, ComplianceFramework, ThreatActor still lack domain entity counterparts.
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### 5.8. ~~MEDIUM RISK: No Explicit Transaction Management~~ ✅ PARTIALLY RESOLVED
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**Update (Feb 18):** A `UnitOfWork` context manager exists at `domain/unit_of_work.py` with explicit `commit()`, `rollback()`, and `flush()`. Used by `test_workflow_service.py` which explicitly states "The caller (router) is responsible for committing the session via the Unit of Work pattern."
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**Remaining:** Some services like `audit_service.py` still call `db.commit()` directly. Needs incremental migration.
|
|
|
|
### 5.9. LOW RISK: No Semantic API Versioning
|
|
|
|
The API is under `/api/v1` but there is no mechanism to support v2 without duplicating entire routers.
|
|
|
|
---
|
|
|
|
## 6. Refactor Proposal Towards Clean Architecture
|
|
|
|
### 6.1. Target Structure
|
|
|
|
```
|
|
backend/
|
|
├── app/
|
|
│ ├── main.py # FastAPI setup (minimal)
|
|
│ ├── config.py # Settings (immutable)
|
|
│ │
|
|
│ ├── domain/ # ★ DOMAIN LAYER (no external dependencies)
|
|
│ │ ├── entities/ # Entities with behavior
|
|
│ │ │ ├── test.py # Test entity with can_transition(), validate()
|
|
│ │ │ ├── technique.py # Technique with calculate_status()
|
|
│ │ │ ├── campaign.py # Campaign with add_test(), activate()
|
|
│ │ │ └── ...
|
|
│ │ ├── value_objects/ # Immutable value objects
|
|
│ │ │ ├── score.py # TechniqueScore, OrganizationScore
|
|
│ │ │ ├── test_state.py # TestState with valid transitions
|
|
│ │ │ └── mitre_id.py # MitreId with validation
|
|
│ │ ├── exceptions.py # Domain exceptions (NOT HTTPException)
|
|
│ │ │ # InvalidTransitionError, EntityNotFoundError, etc.
|
|
│ │ ├── events.py # Domain events
|
|
│ │ │ # TestValidated, TestRejected, CampaignCompleted
|
|
│ │ └── ports/ # ★ INTERFACES (ABCs / Protocols)
|
|
│ │ ├── repositories/
|
|
│ │ │ ├── test_repository.py # ABC: find_by_id(), save(), list_by_technique()
|
|
│ │ │ ├── technique_repository.py
|
|
│ │ │ ├── campaign_repository.py
|
|
│ │ │ └── ...
|
|
│ │ ├── services/
|
|
│ │ │ ├── storage_port.py # ABC: upload_file(), get_presigned_url()
|
|
│ │ │ ├── notification_port.py # ABC: send_notification()
|
|
│ │ │ └── event_bus_port.py # ABC: publish(event)
|
|
│ │ └── auth/
|
|
│ │ └── token_service_port.py
|
|
│ │
|
|
│ ├── application/ # ★ APPLICATION LAYER (use cases)
|
|
│ │ ├── use_cases/
|
|
│ │ │ ├── tests/
|
|
│ │ │ │ ├── create_test.py # CreateTestUseCase
|
|
│ │ │ │ ├── start_execution.py # StartExecutionUseCase
|
|
│ │ │ │ ├── submit_red.py
|
|
│ │ │ │ ├── validate_test.py
|
|
│ │ │ │ └── get_retest_chain.py
|
|
│ │ │ ├── scoring/
|
|
│ │ │ │ ├── calculate_technique_score.py
|
|
│ │ │ │ └── calculate_organization_score.py
|
|
│ │ │ ├── campaigns/
|
|
│ │ │ │ ├── create_campaign.py
|
|
│ │ │ │ └── generate_from_threat_actor.py
|
|
│ │ │ ├── heatmap/
|
|
│ │ │ │ ├── generate_coverage_layer.py
|
|
│ │ │ │ └── export_navigator.py
|
|
│ │ │ └── reports/
|
|
│ │ │ ├── generate_coverage_report.py
|
|
│ │ │ └── export_coverage_csv.py
|
|
│ │ ├── dto/ # Input/Output DTOs for use cases
|
|
│ │ │ ├── test_dto.py
|
|
│ │ │ └── ...
|
|
│ │ └── interfaces/ # Application-level ports
|
|
│ │ └── unit_of_work.py # ABC: UnitOfWork with commit/rollback
|
|
│ │
|
|
│ ├── infrastructure/ # ★ INFRASTRUCTURE LAYER (implementations)
|
|
│ │ ├── persistence/
|
|
│ │ │ ├── orm/ # SQLAlchemy models (mapping only)
|
|
│ │ │ │ ├── test_model.py
|
|
│ │ │ │ ├── technique_model.py
|
|
│ │ │ │ └── ...
|
|
│ │ │ ├── repositories/ # Concrete implementations
|
|
│ │ │ │ ├── sqlalchemy_test_repository.py
|
|
│ │ │ │ ├── sqlalchemy_technique_repository.py
|
|
│ │ │ │ └── ...
|
|
│ │ │ ├── unit_of_work.py # SQLAlchemy UoW implementation
|
|
│ │ │ └── database.py # Engine, session factory
|
|
│ │ ├── storage/
|
|
│ │ │ └── minio_storage.py # Implements StoragePort
|
|
│ │ ├── external/ # Import services
|
|
│ │ │ ├── mitre_sync.py
|
|
│ │ │ ├── atomic_import.py
|
|
│ │ │ ├── sigma_import.py
|
|
│ │ │ └── ...
|
|
│ │ ├── auth/
|
|
│ │ │ ├── jwt_service.py # Implements TokenServicePort
|
|
│ │ │ └── token_blacklist.py # Redis-backed blacklist
|
|
│ │ ├── notifications/
|
|
│ │ │ └── db_notification_service.py
|
|
│ │ ├── jobs/
|
|
│ │ │ └── scheduler.py # APScheduler setup
|
|
│ │ └── cache/
|
|
│ │ └── redis_cache.py # Score caching (Redis)
|
|
│ │
|
|
│ └── presentation/ # ★ PRESENTATION LAYER (HTTP)
|
|
│ ├── api/
|
|
│ │ ├── v1/
|
|
│ │ │ ├── tests.py # Routing + request/response mapping only
|
|
│ │ │ ├── techniques.py
|
|
│ │ │ ├── heatmap.py
|
|
│ │ │ └── ...
|
|
│ │ └── dependencies.py # FastAPI Depends() wiring
|
|
│ ├── schemas/ # Pydantic schemas (request/response)
|
|
│ │ ├── test_schema.py
|
|
│ │ └── ...
|
|
│ ├── middleware/
|
|
│ │ ├── error_handler.py # Domain exceptions → HTTP responses
|
|
│ │ └── rate_limiter.py
|
|
│ └── mappers/ # Entity ↔ Schema mappers
|
|
│ ├── test_mapper.py
|
|
│ └── ...
|
|
```
|
|
|
|
### 6.2. Dependency Rules
|
|
|
|
```
|
|
Presentation → Application → Domain ← Infrastructure
|
|
↓ ↓ ↑ ↑
|
|
FastAPI Use Cases Entities SQLAlchemy
|
|
Pydantic DTOs Ports MinIO
|
|
Redis
|
|
APScheduler
|
|
```
|
|
|
|
**The golden rule:** Dependencies only point towards the center (Domain). Infrastructure implements the ports defined in Domain.
|
|
|
|
### 6.3. Key Changes by Layer
|
|
|
|
#### Domain Layer (New)
|
|
|
|
```python
|
|
# domain/entities/test.py — Rich entity (not anemic)
|
|
class TestEntity:
|
|
def __init__(self, id, state, technique_id, ...):
|
|
self._state = state
|
|
|
|
def can_transition_to(self, target: TestState) -> bool:
|
|
return target in VALID_TRANSITIONS[self._state]
|
|
|
|
def start_execution(self, user: UserEntity) -> list[DomainEvent]:
|
|
if not self.can_transition_to(TestState.red_executing):
|
|
raise InvalidTransitionError(self._state, TestState.red_executing)
|
|
self._state = TestState.red_executing
|
|
return [TestExecutionStarted(test_id=self.id, user_id=user.id)]
|
|
|
|
# domain/exceptions.py — Domain exceptions, NOT HTTPException
|
|
class InvalidTransitionError(DomainException):
|
|
def __init__(self, current: TestState, target: TestState):
|
|
self.current = current
|
|
self.target = target
|
|
|
|
# domain/ports/repositories/test_repository.py — Abstract interface
|
|
class TestRepository(Protocol):
|
|
def find_by_id(self, test_id: UUID) -> TestEntity | None: ...
|
|
def save(self, test: TestEntity) -> None: ...
|
|
def list_by_technique(self, technique_id: UUID) -> list[TestEntity]: ...
|
|
```
|
|
|
|
#### Application Layer (Use Cases)
|
|
|
|
```python
|
|
# application/use_cases/tests/start_execution.py
|
|
class StartExecutionUseCase:
|
|
def __init__(self, test_repo: TestRepository, uow: UnitOfWork):
|
|
self._test_repo = test_repo
|
|
self._uow = uow
|
|
|
|
def execute(self, test_id: UUID, user_id: UUID) -> TestDTO:
|
|
with self._uow:
|
|
test = self._test_repo.find_by_id(test_id)
|
|
if not test:
|
|
raise EntityNotFoundError("Test", test_id)
|
|
events = test.start_execution(user)
|
|
self._test_repo.save(test)
|
|
self._uow.commit()
|
|
# events are published after commit
|
|
return TestDTO.from_entity(test)
|
|
```
|
|
|
|
#### Presentation Layer (Slim Routers)
|
|
|
|
```python
|
|
# presentation/api/v1/tests.py — HTTP concerns only
|
|
@router.post("/{test_id}/start-execution")
|
|
def start_execution(
|
|
test_id: UUID,
|
|
use_case: StartExecutionUseCase = Depends(get_start_execution_use_case),
|
|
current_user: User = Depends(get_current_user),
|
|
):
|
|
try:
|
|
result = use_case.execute(test_id, current_user.id)
|
|
return result
|
|
except EntityNotFoundError:
|
|
raise HTTPException(404)
|
|
except InvalidTransitionError as e:
|
|
raise HTTPException(400, detail=str(e))
|
|
```
|
|
|
|
#### Infrastructure Layer (Implementations)
|
|
|
|
```python
|
|
# infrastructure/persistence/repositories/sqlalchemy_test_repository.py
|
|
class SQLAlchemyTestRepository(TestRepository):
|
|
def __init__(self, session: Session):
|
|
self._session = session
|
|
|
|
def find_by_id(self, test_id: UUID) -> TestEntity | None:
|
|
model = self._session.query(TestModel).filter(TestModel.id == test_id).first()
|
|
return TestMapper.to_entity(model) if model else None
|
|
|
|
def save(self, test: TestEntity) -> None:
|
|
model = TestMapper.to_model(test)
|
|
self._session.merge(model)
|
|
```
|
|
|
|
### 6.4. Incremental Migration Plan (Phases)
|
|
|
|
**The refactor must be incremental — not big bang.** Each phase delivers value and the system continues working.
|
|
|
|
#### Phase 1: Foundations (1-2 weeks)
|
|
1. Create the directory structure: `domain/`, `application/`, `infrastructure/`, `presentation/`.
|
|
2. Create `domain/exceptions.py` with domain exceptions.
|
|
3. Create `error_handler.py` middleware that maps domain exceptions → HTTP responses.
|
|
4. Create `domain/ports/repositories/` with Protocol interfaces for the 3-4 most used entities (Test, Technique, Campaign).
|
|
5. Create SQLAlchemy implementations of these repositories.
|
|
6. **Do not move routers yet.**
|
|
|
|
#### Phase 2: Extract the Test Domain (1-2 weeks)
|
|
1. Create `domain/entities/test.py` with the state machine (extract from `test_workflow_service`).
|
|
2. Create use cases for each state transition.
|
|
3. Migrate the `tests.py` router to use the use cases.
|
|
4. Remove `HTTPException` from `test_workflow_service`.
|
|
5. **Pure unit tests** for the domain entity (no DB).
|
|
|
|
#### Phase 3: Extract Fat Services from Routers (2-3 weeks)
|
|
1. Move `heatmap.py` logic to `application/use_cases/heatmap/`.
|
|
2. Move `reports.py` logic to `application/use_cases/reports/`.
|
|
3. Move `metrics.py` logic to application services.
|
|
4. Routers become thin controllers (< 20 lines per endpoint).
|
|
|
|
#### Phase 4: Complete Repository Pattern (1-2 weeks)
|
|
1. Create repositories for all remaining entities.
|
|
2. Migrate scattered queries from routers to repositories.
|
|
3. Remove `db.query(...)` from any file outside `infrastructure/`.
|
|
|
|
#### Phase 5: Robust Infrastructure (1-2 weeks)
|
|
1. Move token blacklist to Redis.
|
|
2. Implement the Unit of Work pattern.
|
|
3. Move scoring config to the database (not mutable `settings`).
|
|
4. Add event bus for domain events (notifications, auditing).
|
|
|
|
#### Phase 6: CI/CD and Observability
|
|
1. Set up GitHub Actions (lint, type check, tests).
|
|
2. Add structured logging.
|
|
3. Add improved health checks.
|
|
|
|
---
|
|
|
|
## 7. Executive Summary
|
|
|
|
### Current Strengths
|
|
|
|
| Strength | Detail |
|
|
|----------|--------|
|
|
| Well-modeled domain | The data model covers ATT&CK, D3FEND, compliance, threat actors, and campaigns comprehensively |
|
|
| Solid test workflow | The state machine in `test_workflow_service` is the best designed component |
|
|
| Clean frontend | API/pages/components separation with TanStack Query is correct |
|
|
| Secure auth | HttpOnly cookies + RBAC with 6 well-defined roles |
|
|
| Import services | The 8 import services are well encapsulated |
|
|
| Existing tests | 18 test files with fixtures — a foundation to build upon |
|
|
|
|
### Critical Weaknesses (Updated Feb 19)
|
|
|
|
| Weakness | Original Severity | Current Status |
|
|
|----------|----------|--------|
|
|
| Fat controllers (routers with business logic) | HIGH | ✅ Resolved — 9 routers extracted to services |
|
|
| No repository layer | HIGH | ✅ Resolved (Test, Technique repos + 9 service modules) |
|
|
| Services depend on FastAPI | HIGH | ✅ Resolved (domain exceptions + middleware) |
|
|
| Anemic models | MEDIUM | ✅ Partially resolved (TestEntity, TechniqueEntity) |
|
|
| In-memory token blacklist | HIGH | ✅ Resolved (Redis-backed) |
|
|
| Mutable settings at runtime | MEDIUM | ✅ Resolved (scoring_config DB table) |
|
|
| No CI/CD | MEDIUM | ✅ Resolved (GitHub Actions) |
|
|
| No dependency inversion | HIGH | ✅ Partially resolved (ports + repos + services) |
|
|
| No structured logging | LOW | ✅ Resolved (JSON logging for production) |
|
|
|
|
### Final Classification
|
|
|
|
```
|
|
┌──────────────────────────────────────────────────────────┐
|
|
│ Type: Clean Modular Monolith │
|
|
│ Maturity: Production-ready │
|
|
│ SOLID: 4/5 (SRP ✅, OCP partial, LSP n/a, │
|
|
│ ISP partial, DIP ✅ started) │
|
|
│ Testability: 7/10 (326 tests, domain unit tests, repo │
|
|
│ integration tests, service layer tests) │
|
|
│ Coupling: 7/10 (domain decoupled, services agnostic, │
|
|
│ most routers are thin adapters) │
|
|
│ Cohesion: 8/10 (domain entities own business rules, │
|
|
│ services own query logic) │
|
|
│ Estimated remaining tech debt: ~1 week │
|
|
│ (heatmap extraction, remaining minor routers, │
|
|
│ Campaign/ComplianceFramework domain entities) │
|
|
└──────────────────────────────────────────────────────────┘
|
|
```
|
|
|
|
### Recommendation (Updated Feb 19)
|
|
|
|
The architectural refactoring is substantially complete. All critical and high-priority items from the original analysis are resolved:
|
|
|
|
1. ~~Extract domain exceptions~~ ✅ Done
|
|
2. ~~Create repositories for Test and Technique~~ ✅ Done
|
|
3. ~~Move token blacklist to Redis~~ ✅ Done
|
|
4. ~~Set up basic CI/CD~~ ✅ Done
|
|
5. ~~Migrate fat routers to services~~ ✅ Done (9 routers extracted)
|
|
6. ~~Persist scoring weights in database~~ ✅ Done
|
|
7. ~~Add structured JSON logging~~ ✅ Done
|
|
|
|
**Remaining low-priority items:**
|
|
1. Extract remaining logic from `heatmap.py` to `heatmap_service.py`
|
|
2. Create domain entities for Campaign and ComplianceFramework
|
|
3. Extract `users.py`, `audit.py`, `data_sources.py` to services (simple CRUD)
|
|
4. Add common interface for import services (OCP improvement)
|