Files
lmxopcua/docs
Joseph Doherty 3a6b2a1daf feat(acl): variable-depth scope model + the scopePaths producer (#520 stage 3)
Makes the /raw device tree addressable by an ACL rule, and builds the
scope-path producer PermissionTrieBuilder has accepted since it was written
but which had no caller anywhere.

The plan for this stage said "add NodeHierarchyKind.Raw, whose path is the
RawPath segments Folder/Driver/Device/TagGroup/Tag". That shape is wrong.
RawFolder.ParentRawFolderId and TagGroup.ParentTagGroupId are both
self-referencing, so folders and tag groups each nest without bound and a real
RawPath is folder…/Driver/Device/group…/Tag. NodeScope was fixed-arity and
PermissionTrie.CollectMatches was five hardcoded steps, so the scope model
could not address a real raw tree at all. NodeScope is now {ClusterId, Kind,
Segments} and the walk is a segment loop. The trie STRUCTURE was already
variable-depth (NodeAclPath.Segments is a list, Children is a recursive
dictionary), so only the walker and the scope record had to change.

Four decisions worth keeping:

- The namespace level became the realm. Level 1 gated on NodeScope.NamespaceId,
  but v3 has no Namespace entity — the snapshot was retired when the address
  space went dual-namespace, and the identifier appears nowhere in production
  outside NodeScope. So the level could only ever fail to match, which silently
  made every sub-cluster grant unreachable while cluster grants kept working.
  It is now a realm token derived from the scope's Kind, not carried on it, so
  the walk and the producer cannot disagree about its spelling.
- Provenance comes from the granting row's own ScopeKind, recorded on TrieGrant
  at build time. Depth-derived provenance could not name a raw level at all,
  since the depth of "Device" varies with folder nesting.
- The trie comparer moved from OrdinalIgnoreCase to Ordinal. Raw sibling-name
  uniqueness is ordinal, so Speed and speed can both exist under one device and
  a grant on either would have matched both.
- The null-scopePaths "deterministic test mode" is deleted. It planted
  unresolvable rows at a direct child of the trie root, a position the walker
  cannot reach, so the grant looked placed and could never match — and every
  test using that mode proved nothing about production placement. scopePaths is
  now required, and a row that does not resolve is dropped with a diagnostic.

A scope resolves to a LIST of paths: a raw tag projected into N equipments is
reachable at N+1 NodeIds and a write through any of them lands on the same
driver reference, so a Tag-scoped grant covering only the raw node would be
bypassable through a UNS one. The lookup is keyed on (ScopeKind, ScopeId), not
ScopeId alone — ScopeId has no FK and no type discriminator, so an id collision
across entity types would hand a grant the wrong node's paths.

Also closed here, all found by review rather than asked for:

- NodeAcl rows had no deploy-time validation of any kind and were not reachable
  from DraftValidator at all (DraftSnapshot carried no NodeAcls). They are now
  gated for dangling ids, cross-cluster scopes, blank/contradictory ScopeId, the
  retired FolderSegment kind, and undefined ordinals.
- ConfigDbApiKeyStore conferred roles from Cluster-scoped grants authored in ANY
  cluster, because it filtered on scope kind with no ClusterId predicate while
  ArtifactApiKeyStore read an already-cluster-filtered snapshot. On a fused
  admin+driver node that was a cross-cluster over-grant. Its doc comment claimed
  the two stores matched.
- The two AdminUI ACL banners still said enforcement was LDAP-group -> role
  mapping, which stages 1/2 made false in both directions.
- The /apikeys page was never classified in PageAuthorizationGuardTests, so that
  test has been red since the key-minting commit merged — I did not run
  AdminUI.Tests before merging stage 4.

Falsified rather than assumed: 8 mutations against the trie tests, 5 against the
deploy gate (including one proving a cross-cluster row is not silently
mis-diagnosed as unresolved), a staged red->green for the over-grant regression,
and the realm gate, the comparer and the malformed-path guard each broken
individually to confirm only their own tests go red.

Node ACLs are still not ENFORCED — nothing constructs a NodeScope or calls the
evaluator yet. That is stages 5 and 6; this stage makes the model able to
express what those will enforce.

Claude-Session: https://claude.ai/code/session_015p7wGqy3YpZNCpDzTpGMKo
2026-08-01 01:07:59 -04:00
..

OtOpcUa documentation

Two tiers of documentation live here:

  • Current reference at the top level (docs/*.md) — describes what's shipped today. Start here for operator + integrator reference.
  • Implementation history + design notes at docs/v2/*.md — the authoritative plan + decision log the current reference is built from. Start here when you need the why behind an architectural choice, or when a top-level doc says "see plan.md § X".

The project was originally called LmxOpcUa (a single-driver Galaxy/MXAccess OPC UA server) and has since become OtOpcUa, a multi-driver OPC UA server platform. Any lingering LmxOpcUa-string in a path you see in docs is a deliberate residual (executable name lmxopcua-cli, client PKI folder {LocalAppData}/LmxOpcUaClient/) — fixing those requires migration shims + is tracked as follow-ups.

Platform overview

v2 (2026-05-26): the separate OtOpcUa.Server + OtOpcUa.Admin services fused into a single role-gated OtOpcUa.Host binary, joined by an Akka.NET cluster. See v2 design for the architectural decision.

  • Core owns shared abstractions (driver capability contracts, scripting, virtual tags, alarm historian).
  • Drivers plug in via capability interfaces in ZB.MOM.WW.OtOpcUa.Core.Abstractions: IDriver, IReadable, IWritable, ITagDiscovery, ISubscribable, IHostConnectivityProbe, IAlarmSource, IHistoryProvider, IPerCallHostResolver. Each driver opts into whichever it supports.
  • Host (src/Server/ZB.MOM.WW.OtOpcUa.Host) is the single fused binary (.NET 10, AnyCPU). OTOPCUA_ROLES env decides what to mount: admin (Blazor + control-plane singletons), driver (OPC UA endpoint + per-node actors), or both. See ServiceHosting.md.
  • Cluster + ControlPlane + Runtime + AdminUI + Security sit between Core and Host. The cluster glues per-node actors into one logical fleet; the control-plane singletons (deploy coordinator, audit writer, redundancy state) live on the admin role-leader. See Redundancy.md.
  • The Galaxy driver still reaches MXAccess via gRPC to a separately-installed mxaccessgw sidecar (sibling repo).

Where to find what

Architecture + data-path reference

Doc Covers
OpcUaServer.md Top-level server architecture — Core, driver dispatch, Config DB, generations
AddressSpace.md GenericDriverNodeManager + ITagDiscovery + IAddressSpaceBuilder
ReadWriteOperations.md OPC UA Read/Write → CapabilityInvoker → IReadable/IWritable
DriverLifecycle.md Server-side driver lifecycle + infrastructure contracts (IDriverFactory, IDriverProbe, IDriverHealthPublisher, IDriverConfigEditor, IHistorianDataSource) + the Commons library
Subscriptions.md Monitored items → ISubscribable + per-driver subscription refcount (v1 archive)
AlarmTracking.md IAlarmSource + AlarmSurfaceInvoker + OPC UA alarm conditions — native Galaxy alarms end-to-end (live)
AlarmTracking.md Original alarm-tracking write-up (v1 archive)
AlarmHistorian.md Core.AlarmHistorian store-and-forward sink — LocalDbStoreAndForwardSink, the replicated alarm_sf_events buffer + Primary-only drain, IAlarmHistorianWriter, dead-letter/retry/eviction
DataTypeMapping.md Per-driver DriverAttributeInfo → OPC UA variable types (v1 archive — live mapping is in src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Browse/DataTypeMap.cs)
IncrementalSync.md Address-space rebuild on redeploy + sp_ComputeGenerationDiff
HistoricalDataAccess.md IHistoryProvider as a per-driver optional capability (v1 archive)
VirtualTags.md Core.Scripting + Core.VirtualTags — Roslyn script sandbox, engine, dispatch alongside driver tags
ScriptEditor.md Monaco script editor — Roslyn-backed IntelliSense (completions, diagnostics, hover, tag-path) for C# virtual-tag scripts; AdminUI/ScriptAnalysis/ backend
ScriptedAlarms.md Core.ScriptedAlarms — script-predicate IAlarmSource + Part 9 state machine

One Core subsystem is shipped without a dedicated top-level doc; see the section in the linked doc:

Project See
Analyzers (Roslyn OTOPCUA0001) security.md § OTOPCUA0001 Analyzer

Drivers

Doc Covers
drivers/README.md Index of the eight shipped drivers + capability matrix
drivers/Galaxy.md Galaxy driver — in-process gRPC client to the mxaccessgw sidecar
v1/drivers/Galaxy-Repository.md Galaxy-specific discovery via the ZB SQL database (v1 archive — the gateway owns this path now)

For Modbus / S7 / AB CIP / AB Legacy / TwinCAT / FOCAS / OPC UA Client specifics, see v2/driver-specs.md.

Operational

Doc Covers
Configuration.md Live appsettings + environment-variable reference (current state)
Configuration.md appsettings bootstrap + Config DB + Admin UI draft/publish (v1 archive — OTOPCUA_GALAXY_* env vars now live in mxaccessgw config)
Uns.md The global /uns master tree — manage Area/Line/Equipment/Tag/VirtualTag fleet-wide; replaces the per-cluster UNS/Equipment/Tags tabs
security.md Transport security profiles, LDAP auth, ACL trie, role grants, OTOPCUA0001 analyzer
Redundancy.md RedundancyStateActor (cluster-scoped singleton), ServiceLevelCalculator, IRedundancyRoleView, per-cluster meshes, Prometheus metrics
Reservations.md Fleet-wide ZTag / SAPID external-ID reservations — publish-time claim, release flow
ServiceHosting.md Single fused OtOpcUa.Host binary install/uninstall with OTOPCUA_ROLES gating; the historian backend is the external HistorianGateway
StatusDashboard.md Pointer — superseded by v2/admin-ui.md

Client tooling

Doc Covers
Client.CLI.md otopcua-cli — OPC UA command-line client
Client.UI.md Avalonia desktop client
DriverClis.md Driver test-client CLIs — index + shared commands
Driver.Modbus.Cli.md otopcua-modbus-cli — Modbus-TCP
Driver.AbCip.Cli.md otopcua-abcip-cli — ControlLogix / CompactLogix / Micro800 / GuardLogix
Driver.AbLegacy.Cli.md otopcua-ablegacy-cli — SLC / MicroLogix / PLC-5 (PCCC)
Driver.S7.Cli.md otopcua-s7-cli — Siemens S7-300 / S7-400 / S7-1200 / S7-1500
Driver.TwinCAT.Cli.md otopcua-twincat-cli — Beckhoff TwinCAT 2/3 ADS
Driver.FOCAS.Cli.md otopcua-focas-cli — Fanuc FOCAS/2 CNC

Requirements

Doc Covers
reqs/HighLevelReqs.md HLRs — numbered system-level requirements
reqs/OpcUaServerReqs.md OPC UA server-layer reqs
v1/reqs/ServiceHostReqs.md Per-process hosting reqs (v1 archive — only OtOpcUa server hosting remains in scope post-PR-7.2)
reqs/ClientRequirements.md Client CLI + UI reqs
v1/reqs/GalaxyRepositoryReqs.md Galaxy-scoped repository reqs (v1 archive — owned by mxaccessgw today)
v1/reqs/MxAccessClientReqs.md Galaxy-scoped MXAccess reqs (v1 archive — owned by mxaccessgw today)
reqs/StatusDashboardReqs.md Pointer — superseded by Admin UI

Implementation history (docs/v2/)

Design decisions + phase plans + execution notes. Load-bearing cross-references from the top-level docs:

v1 archive

The v1 in-process MXAccess architecture (Galaxy.Host + Galaxy.Proxy + Galaxy.Shared, .NET 4.8 x86 COM, the OtOpcUaGalaxyHost Windows service) was retired in PR 7.2 (2026-04-30, commit ae7106d). Docs that described that shape are kept under v1/ as historical record — see v1/README.md for the index.