Joseph DohertyScadaBridge
ScadaBridge is a centrally-managed, distributed SCADA configuration and deployment platform built on Akka.NET, running across a central cluster and multiple site clusters in a hub-and-spoke topology.
Overview
This repository is the full implementation project for ScadaBridge — the C#/.NET source (src/), tests (tests/), deployable Docker topology (docker/, docker-env2/, infra/), and the design documentation (docs/) that the code implements. This README is the master index: it links the per-component design specs (the spec the code in src/ implements), the per-component reference docs (how the shipped code works), and shows the system architecture. The solution file is ZB.MOM.WW.ScadaBridge.slnx.
Technology Stack
| Layer | Technology |
|---|---|
| Runtime | .NET, Akka.NET (actors, clustering, remoting, persistence, streams) |
| Central UI | Blazor Server (ASP.NET Core + SignalR) |
| Inbound API | ASP.NET Core Web API (REST/JSON) |
| Central Database | MS SQL Server, Entity Framework Core |
| Site Storage | SQLite (deployed configs, S&F buffer, event logs) |
| Authentication | Direct LDAP/AD bind (LDAPS/StartTLS), JWT sessions |
| Notifications | Delivered from the central cluster (SMTP, OAuth2/Microsoft 365); store-and-forwarded from sites |
| Hosting | Windows Server, Windows Service |
| Cluster | Akka.NET Cluster (active/standby, keep-oldest SBR) |
| Logging | Serilog (structured) |
Scale
- Central cluster: 2-node active/standby behind a load balancer.
- Site clusters: 2-node active/standby, headless (no UI).
Repository Layout
| Path | Contents |
|---|---|
src/ |
C#/.NET implementation — one project per component (ZB.MOM.WW.ScadaBridge.<Component>). Solution: ZB.MOM.WW.ScadaBridge.slnx. |
tests/ |
Unit and integration test projects. |
docs/ |
Documentation — docs/requirements/ (high-level + per-component specs, the spec the code implements), docs/components/ (per-component developer reference — how the code works), docs/test_infra/, docs/plans/. |
docker/ |
Primary 8-node cluster topology (2 central + 3 sites × 2 nodes + Traefik) + deploy.sh. |
docker-env2/ |
Minimal second cluster (2 central + 1 site) for exercising Transport (#24) against a real second environment. |
infra/ |
Local test services (MS SQL, LDAP, OPC UA, SMTP, REST API, Traefik). |
deploy/ |
Production/on-host deployment artifacts (e.g. wonder-app-vd03/). |
AkkaDotNet/ |
Akka.NET reference notes. |
Build, Test & Run
# Build the solution
dotnet build ZB.MOM.WW.ScadaBridge.slnx
# Run the tests
dotnet test ZB.MOM.WW.ScadaBridge.slnx
# Bring up the primary local cluster (builds the scadabridge:latest image + recreates containers)
bash docker/deploy.sh # central load balancer at http://localhost:9000
# Drive the system from the CLI (reads ~/.scadabridge/config.json; test user has all roles)
dotnet run --project src/ZB.MOM.WW.ScadaBridge.CLI -- \
--username multi-role --password password template list
See docker/README.md for ports and management commands, and src/ZB.MOM.WW.ScadaBridge.CLI/README.md for the full CLI reference.
Local Test Environments
Two Docker-based cluster topologies are available for local development and testing:
- Primary (
docker/) — Full topology (2 central + 3 sites × 2 nodes + Traefik). Default development target. - Env2 (
docker-env2/) — Minimal sibling stack (2 central + 1 site × 2 nodes + Traefik), runs concurrently with primary on host ports 91XX. Purpose: exercise the Transport (#24) bundle export/import feature against a real second environment.
Both stacks share the infrastructure services in infra/ (MS SQL, LDAP, SMTP, OPC UA, REST API).
Document Map
Requirements
- HighLevelReqs.md — Complete high-level requirements covering all functional areas.
Component Design Documents
| # | Component | Document | Description |
|---|---|---|---|
| 1 | Template Engine | docs/requirements/Component-TemplateEngine.md | Template modeling, inheritance, composition, path-qualified member addressing, override granularity, locking, alarms, native alarm source bindings, flattening, semantic validation, revision hashing, diff calculation, and folder organization (nested folders, drag-drop). |
| 2 | Deployment Manager | docs/requirements/Component-DeploymentManager.md | Central-side deployment pipeline with deployment ID/idempotency, per-instance operation lock, state transition matrix, all-or-nothing site apply, system-wide artifact deployment with per-site status. |
| 3 | Site Runtime | docs/requirements/Component-SiteRuntime.md | Site-side actor hierarchy with explicit supervision strategies, staggered startup, script trust model (constrained APIs), Tell/Ask conventions, concurrency serialization, site-wide Akka stream with per-subscriber backpressure, and a read-only Native Alarm Actor (peer to the computed Alarm Actor) mirroring native OPC UA A&C / MxAccess alarms with site SQLite persistence. |
| 4 | Data Connection Layer | docs/requirements/Component-DataConnectionLayer.md | Common data connection interface (OPC UA, MxGateway, custom), Become/Stash connection actor model, auto-reconnect, immediate bad quality on disconnect, transparent re-subscribe, synchronous write failures, tag path resolution retry, protocol-agnostic address-space browse, and optional read-only native alarm mirroring (IAlarmSubscribableConnection, one alarm feed per connection with snapshot replay). |
| 5 | Central–Site Communication | docs/requirements/Component-Communication.md | Dual transport: Akka.NET ClusterClient (command/control) + gRPC server-streaming (real-time data). 9 message patterns with per-pattern timeouts, SiteStreamGrpcServer/Client, application-level correlation IDs, transport heartbeat config, gRPC keepalive, message ordering, connection failure behavior. The gRPC stream additively carries the read-only native alarm mirror (computed + native OPC UA / MxAccess) via the enriched AlarmStateUpdate. |
| 6 | Store-and-Forward Engine | docs/requirements/Component-StoreAndForward.md | Buffering (transient failures only), fixed-interval retry, parking, async best-effort replication, SQLite persistence at sites. |
| 7 | External System Gateway | docs/requirements/Component-ExternalSystemGateway.md | HTTP/REST + JSON, API key/Basic Auth, per-system timeout, dual call modes (Call/CachedCall), transient/permanent error classification, dedicated blocking I/O dispatcher, ADO.NET connection pooling. |
| 8 | Notification Service | docs/requirements/Component-NotificationService.md | Central-only — manages typed notification-list and SMTP definitions, supplies per-type delivery adapters (SMTP with OAuth2 (M365) or Basic Auth, BCC, plain text); delivery performed by the Notification Outbox. |
| 9 | Central UI | docs/requirements/Component-CentralUI.md | Blazor Server with SignalR real-time push, load balancer failover with JWT, all management workflows. |
| 10 | Security & Auth | docs/requirements/Component-Security.md | Direct LDAP bind (LDAPS/StartTLS), JWT sessions (HMAC-SHA256, 15-min refresh, 30-min idle), role-based authorization, site-scoped permissions. |
| 11 | Health Monitoring | docs/requirements/Component-HealthMonitoring.md | 30s report interval, 60s offline threshold, monotonic sequence numbers, raw error counts, tag resolution counts, dead letter monitoring. |
| 12 | Site Event Logging | docs/requirements/Component-SiteEventLogging.md | SQLite storage, 30-day retention + 1GB cap, daily purge, paginated remote queries with keyword search. |
| 13 | Cluster Infrastructure | docs/requirements/Component-ClusterInfrastructure.md | Akka.NET cluster, keep-oldest SBR with down-if-alone, min-nr-of-members=1, 2s/10s/15s failure detection, CoordinatedShutdown, automatic dual-node recovery. The ClusterInfrastructure project owns the ClusterOptions config model; the Akka bootstrap/SBR/CoordinatedShutdown wiring lives in the Host. |
| 14 | Inbound API | docs/requirements/Component-InboundAPI.md | POST /api/{methodName}, X-API-Key header, flat JSON, extended type system (Object/List), script-based implementations, failures-only logging. |
| 15 | Host | docs/requirements/Component-Host.md | Single deployable binary, role-based component registration, per-component config binding (Options pattern), readiness gating, dead letter monitoring, Akka.NET bootstrap, ASP.NET Core hosting for central. |
| 16 | Commons | docs/requirements/Component-Commons.md | Namespace/folder convention (Types/Interfaces/Entities/Messages), shared data types, POCOs, repository interfaces, message contracts with additive-only versioning, UTC timestamp convention, the unified read-only alarm condition model (AlarmConditionState/AlarmKind), and native alarm source entities + the IAlarmSubscribableConnection capability seam. |
| 17 | Configuration Database | docs/requirements/Component-ConfigurationDatabase.md | EF Core data access, per-component repositories, unit-of-work, optimistic concurrency on deployment status, audit logging (IAuditService), migration management (incl. the AddNativeAlarmSources migration + native alarm source repository CRUD). |
| 18 | Management Service | docs/requirements/Component-ManagementService.md | Akka.NET ManagementActor on central, ClusterClientReceptionist registration, programmatic access to all admin operations, CLI interface. |
| 19 | CLI | docs/requirements/Component-CLI.md | Standalone command-line tool, System.CommandLine, HTTP transport via Management API, JSON/table output, mirrors all Management Service operations. |
| 20 | Traefik Proxy | docs/requirements/Component-TraefikProxy.md | Reverse proxy/load balancer fronting central cluster, active node routing via /health/active, automatic failover. |
| 21 | Notification Outbox | docs/requirements/Component-NotificationOutbox.md | Central component ingesting store-and-forwarded notifications into the Notifications audit table, with NotificationOutboxActor singleton dispatcher, per-type delivery adapters, retry/parking, status tracking, daily purge, and delivery KPIs. |
| 22 | Site Call Audit | docs/requirements/Component-SiteCallAudit.md | Central component auditing site cached calls (ExternalSystem.CachedCall/Database.CachedWrite) into the SiteCalls audit table, with SiteCallAuditActor singleton, telemetry ingest, periodic reconciliation, point-in-time KPIs, daily purge, and central→site Retry/Discard relay for parked calls. |
| 23 | Audit Log | docs/requirements/Component-AuditLog.md | New central append-only AuditLog spanning every script-trust-boundary action (outbound API sync+cached, outbound DB sync+cached, notifications, inbound API). Site-local SQLite hot-path append + gRPC telemetry + central reconciliation; combined telemetry packet with Site Call Audit; central direct-write for Notification Outbox dispatch + Inbound API middleware; monthly partitioning, 365-day default retention. |
| 24 | Transport | docs/requirements/Component-Transport.md | Bundle export/import for templates, shared scripts, external systems, central-only artifacts. AES-256-GCM encryption; per-conflict resolution on import; correlated audit trail. |
Shared UI sub-component (not a top-level component): TreeView — reusable hierarchical tree/grid Blazor component used by the Central UI (#9) for the templates folder hierarchy, data-connection browse, and tag pickers.
Component Reference Documentation
The design documents above are the specs (what each component does and why). For developer reference docs that describe how the shipped code works — with real code examples, drawn from src/ and written to the Style Guide — see docs/components/. One doc per component (plus the shared TreeView), indexed in docs/components/README.md.
Reference Documentation
- AkkaDotNet/ — Akka.NET reference notes covering actors, remoting, clustering, persistence, streams, serialization, hosting, testing, and best practices.
- docs/plans/ — Design decision documents from refinement sessions.
Architecture Diagram (Logical)
Site Runtime Actor Hierarchy
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flowchart TD
DMS["Deployment Manager Singleton<br/>(Cluster Singleton)"]
IA["Instance Actor<br/>(one per deployed, enabled instance)"]
IA2["Instance Actor<br/>( … )"]
MOREIA["… more Instance Actors"]
DMS --> IA
DMS --> IA2
DMS -.-> MOREIA
SA["Script Actor<br/>(coordinator, one per instance script)"]
AA["Alarm Actor<br/>(coordinator, one per alarm definition)"]
MORE1["… more Script /<br/>Alarm Actors"]
IA --> SA
IA --> AA
IA -.-> MORE1
SEA["Script Execution Actor<br/>(short-lived, per invocation)"]
AEA["Alarm Execution Actor<br/>(short-lived, per on-trigger invocation)"]
IA2C["… (Script / Alarm Actors)"]
SA --> SEA
AA --> AEA
IA2 -.-> IA2C
subgraph STREAM["Site-Wide Akka Stream"]
PUB["All Instance Actors"]
STR["Site-Wide Akka Stream<br/>(attribute + alarm state changes)"]
DBG["Debug view<br/>(instance-level filtering)"]
PUB -->|publish| STR
STR -->|subscribe filtered| DBG
end
classDef start fill:#d5e8d4,stroke:#82b366,color:#111111;
classDef proc fill:#dae8fc,stroke:#6c8ebf,color:#111111;
classDef warn fill:#ffe6cc,stroke:#d79b00,color:#111111;
classDef alt fill:#e1d5e7,stroke:#9673a6,color:#111111;
classDef muted fill:#f5f5f5,stroke:#999999,color:#666666;
class DMS,STR alt
class IA,IA2,PUB proc
class SA,AA,DBG start
class SEA,AEA warn
class MOREIA,MORE1,IA2C muted