Commit Graph

3 Commits

Author SHA1 Message Date
Joseph Doherty
36774842cf Phase 7 Stream A.3 — ScriptLoggerFactory + ScriptLogCompanionSink. Third of 3 increments closing out Stream A. Adds the Serilog plumbing that ties script-emitted log events to the dedicated scripts-*.log rolling sink with structured-property filtering AND forwards script Error+ events to the main opcua-*.log at Warning level so operators see script failures in the primary log without drowning it in Debug/Info script chatter. Both pieces are library-level building blocks — the actual file-sink + logger composition at server startup happens in Stream F (Admin UI) / Stream G (address-space wiring). This PR ships the reusable factory + sink + tests so any consumer can wire them up without rediscovering the structured-property contract.
ScriptLoggerFactory wraps a Serilog root logger (the scripts-*.log pipeline) and .Create(scriptName) returns a per-script ILogger with the ScriptName structured property pre-bound via ForContext. The structured property name is a public const (ScriptNameProperty = "ScriptName") because the Admin UI's log-viewer filter references this exact string — changing it breaks the filter silently, so it's stable by contract. Factory constructor rejects a null root logger; Create rejects null/empty/whitespace script names. No per-evaluation allocation in the hot path — engines (Stream B virtual-tag / Stream C scripted-alarm) create one factory per engine instance then cache per-script loggers beside the ScriptContext instances they already build.

ScriptLogCompanionSink is a Serilog ILogEventSink that forwards Error+ events from the script-logger pipeline to a separate "main" logger (the opcua-*.log pipeline in production) at Warning level. Rationale: operators usually watch the main server log, not scripts-*.log. Script authors log Info/Debug liberally during development — those stay in the scripts file. When a script actually fails (Error or Fatal), the operator needs to see it in the primary log so it can't be missed. Downgrading to Warning in the main log marks these as "needs attention but not a core server issue" since the server itself is healthy; the script author fixes the script. Forwarded event includes the ScriptName property (so operators can tell which script failed at a glance), the OriginalLevel (Error vs Fatal, preserved), the rendered message, and the original exception (preserved so the main log keeps the full stack trace — critical for diagnosis). Missing ScriptName property falls back to "unknown" without throwing; bypassing the factory is defensive but shouldn't happen in practice. Mirror threshold is configurable via constructor (defaults to LogEventLevel.Error) so deployments with stricter signal/noise requirements can raise it to Fatal.

15 new unit tests across two files. ScriptLoggerFactoryTests (6): Create sets the ScriptName structured property, each script gets its own property value across fan-out, Error-level event preserves level and exception, null root rejected, empty/whitespace/null name rejected, ScriptNameProperty const is stable at "ScriptName" (external-contract guard). ScriptLogCompanionSinkTests (9): Info/Warning events land in scripts sink only (not mirrored), Error event mirrored to main at Warning level (level-downgrade behavior), mirrored event includes ScriptName + OriginalLevel properties, mirrored event preserves exception for main-log stack-trace diagnosis, Fatal mirrored identically to Error, missing ScriptName falls back to "unknown" without throwing (defensive), null main logger rejected, custom mirror threshold (raised to Fatal) applied correctly.

Full Core.Scripting test suite after Stream A: 63/63 green (29 A.1 + 19 A.2 + 15 A.3). Stream A is complete — the scripting engine foundation, sandbox, sandbox-defense-in-depth, AST-inferred dependency extraction, compile cache, per-evaluation timeout, per-script logger with structured-property filtering, and companion-warn forwarding are all shipped and tested. Streams B through G build on this; Stream H closes out the phase with the compliance script + test baseline + merge to v2.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-20 16:42:48 -04:00
Joseph Doherty
0ae715cca4 Phase 7 Stream A.2 — compile cache + per-evaluation timeout wrapper. Second of 3 increments within Stream A. Adds two independent resilience primitives that the virtual-tag engine (Stream B) and scripted-alarm engine (Stream C) will compose with the base ScriptEvaluator. Both are generic on (TContext, TResult) so different engines get their own instances without cross-contamination.
CompiledScriptCache<TContext, TResult> — source-hash-keyed cache of compiled evaluators. Roslyn compilation is the most expensive step in the evaluator pipeline (5-20ms per script depending on size); re-compiling on every value-change event would starve the engine. ConcurrentDictionary of Lazy<ScriptEvaluator> with ExecutionAndPublication mode ensures concurrent callers never double-compile even on a cold cache race. Failed compiles evict the cache entry so an Admin UI retry with corrected source actually recompiles (otherwise the cached exception would persist). Whitespace-sensitive hash — reformatting a script misses the cache on purpose, simpler than AST-canonicalize and happens rarely. No capacity bound because virtual-tag + alarm scripts are config-DB bounded (thousands, not millions); if scale pushes past that in v3 an LRU eviction slots in behind the same API.

TimedScriptEvaluator<TContext, TResult> — wraps a ScriptEvaluator with a per-evaluation wall-clock timeout (default 250ms per Phase 7 plan Stream A.4, configurable per tag so slower backends can widen). Critical implementation detail: the underlying Roslyn ScriptRunner executes synchronously on the calling thread for CPU-bound user scripts, returning an already-completed Task before the caller can register a timeout. Naive `Task.WaitAsync(timeout)` would see the completed task and never fire. Fix: push evaluation to a thread-pool thread via Task.Run, so the caller's thread is free to wait and the timeout reliably fires after the configured budget. Known trade-off (documented in the class summary): when a script times out, the underlying evaluation task continues running on the thread-pool thread until Roslyn returns; in the CPU-bound-infinite-loop case it's effectively leaked until the runtime decides to unwind. Tighter CPU budgeting would require an out-of-process script runner (v3 concern). In practice the timeout + structured warning log surfaces the offending script so the operator fixes it, and the orphan thread is rare. Caller-supplied CancellationToken is honored and takes precedence over the timeout, so driver-shutdown paths see a clean OperationCanceledException rather than a misclassified ScriptTimeoutException.

ScriptTimeoutException carries the configured Timeout and a diagnostic message pointing the operator at ctx.Logger output around the failure plus suggesting widening the timeout, simplifying the script, or moving heavy work out of the evaluation path. The virtual-tag engine (Stream B) will catch this and map the owning tag's quality to BadInternalError per Phase 7 decision #11, logging a structured warning with the offending script name.

Tests: CompiledScriptCacheTests (10) — first-call compile, identical-source dedupe to same instance, different-source produces different evaluator, whitespace-sensitivity documented, cached evaluator still runs correctly, failed compile evicted for retry, Clear drops entries, concurrent GetOrCompile of the same source deduplicates to one instance, different TContext/TResult use separate cache instances, null source rejected. TimedScriptEvaluatorTests (9) — fast script completes under timeout, CPU-bound script throws ScriptTimeoutException, caller cancellation takes precedence over timeout (shutdown path correctness), default 250ms per plan, zero/negative timeout rejected at construction, null inner rejected, null context rejected, user-thrown exceptions propagate unwrapped (not conflated with timeout), timeout exception message contains diagnostic guidance. Full suite: 48/48 green (29 from A.1 + 19 new).

Next: Stream A.3 wires the dedicated scripts-*.log Serilog rolling sink + structured-property filtering + companion-WARN enricher to the main log, closing out Stream A.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-20 16:38:43 -04:00
Joseph Doherty
e4dae01bac Phase 7 Stream A.1 — Core.Scripting project scaffold + ScriptContext + sandbox + AST dependency extractor. First of 3 increments within Stream A. Ships the Roslyn-based script engine's foundation: user C# snippets compile against a constrained ScriptOptions allow-list + get a post-compile sandbox guard, the static tag-dependency set is extracted from the AST at publish time, and the script sees a stable ctx.GetTag/SetVirtualTag/Now/Logger/Deadband API that later streams plug into concrete backends.
ScriptContext abstract base defines the API user scripts see as ctx — GetTag(string) returns DataValueSnapshot so scripts branch on quality naturally, SetVirtualTag(string, object?) is the only write path virtual tags have (OPC UA client writes to virtual nodes rejected separately in DriverNodeManager per ADR-002), Now + Logger + Deadband static helper round out the surface. Concrete subclasses in Streams B + C plug in actual tag backends + per-script Serilog loggers.

ScriptSandbox.Build(contextType) produces the ScriptOptions for every compile — explicit allow-list of six assemblies (System.Private.CoreLib / System.Linq / Core.Abstractions / Core.Scripting / Serilog / the context type's own assembly), with a matching import list so scripts don't need using clauses. Allow-list is plan-level — expanding it is not a casual change.

DependencyExtractor uses CSharpSyntaxWalker to find every ctx.GetTag("literal") and ctx.SetVirtualTag("literal", ...) call, rejects every non-literal path (variable, concatenation, interpolation, method-returned). Rejections carry the exact TextSpan so the Admin UI can point at the offending token. Reads + writes are returned as two separate sets so the virtual-tag engine (Stream B) knows both the subscription targets and the write targets.

Sandbox enforcement turned out needing a second-pass semantic analyzer because .NET 10's type forwarding makes assembly-level restriction leaky — System.Net.Http.HttpClient resolves even with WithReferences limited to six assemblies. ForbiddenTypeAnalyzer runs after Roslyn's Compile() against the SemanticModel, walks every ObjectCreationExpression / InvocationExpression / MemberAccessExpression / IdentifierName, resolves to the containing type's namespace, and rejects any prefix-match against the deny-list (System.IO, System.Net, System.Diagnostics, System.Reflection, System.Threading.Thread, System.Runtime.InteropServices, Microsoft.Win32). Rejections throw ScriptSandboxViolationException with the aggregated list + source spans so the Admin UI surfaces every violation in one round-trip instead of whack-a-mole. System.Environment explicitly stays allowed (read-only process state, doesn't persist or leak outside) and that compromise is pinned by a dedicated test.

ScriptGlobals<TContext> wraps the context as a named field so scripts see ctx instead of the bare globalsType-member-access convention Roslyn defaults to — keeps script ergonomics (ctx.GetTag) consistent with the AST walker's parse shape and the Admin UI's hand-written type stub (coming in Stream F). Generic on TContext so Stream C's alarm-predicate context with an Alarm property inherits cleanly.

ScriptEvaluator<TContext, TResult>.Compile is the three-step gate: (1) Roslyn compile — throws CompilationErrorException on syntax/type errors with Location-carrying diagnostics; (2) ForbiddenTypeAnalyzer semantic pass — catches type-forwarding sandbox escapes; (3) delegate creation. Runtime exceptions from user code propagate unwrapped — the virtual-tag engine in Stream B catches + maps per-tag to BadInternalError quality per Phase 7 decision #11.

29 unit tests covering every surface: DependencyExtractorTests has 14 theories — single/multiple/deduplicated reads, separate write tracking, rejection of variable/concatenated/interpolated/method-returned/empty/whitespace paths, ignoring non-ctx methods named GetTag, empty-source no-op, source span carried in rejections, multiple bad paths reported in one pass, nested literal extraction. ScriptSandboxTests has 15 — happy-path compile + run, SetVirtualTag round-trip, rejection of File.IO + HttpClient + Process.Start + Reflection.Assembly.Load via ScriptSandboxViolationException, Environment.GetEnvironmentVariable explicitly allowed (pinned compromise), script-exception propagation, ctx.Now reachable, Deadband static reachable, LINQ Where/Sum reachable, DataValueSnapshot usable in scripts including quality branches, compile error carries source location.

Next two PRs within Stream A: A.2 adds the compile cache (source-hash keyed) + per-evaluation timeout wrapper; A.3 wires the dedicated scripts-*.log Serilog rolling sink with structured-property filtering + the companion-warning enricher to the main log.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-20 16:27:07 -04:00