feat(telemetry): AddZbTelemetry metrics+traces bootstrap

2026-06-01 07:33:51 -04:00
parent 215a646e35
commit 4126e1df54
2 changed files with 214 additions and 0 deletions
@@ -0,0 +1,82 @@
+using System.Diagnostics.Metrics;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.DependencyInjection;
+using OpenTelemetry;
+using OpenTelemetry.Metrics;
+using OpenTelemetry.Resources;
+using ZB.MOM.WW.Telemetry;
+
+namespace ZB.MOM.WW.Telemetry.Tests;
+
+public sealed class AddZbTelemetryTests
+{
+    [Fact]
+    public void AddZbTelemetry_ExportsAppMeter_WithSharedResource()
+    {
+        // 1.15.x note: AddInMemoryExporter moved out of the core OpenTelemetry assembly into a
+        // separate OpenTelemetry.Exporter.InMemory package (not referenced here). We attach a
+        // BaseExporter<Metric> directly instead — it both collects metric names and exposes the
+        // MeterProvider Resource via ParentProvider.GetResource().
+        var capture = new CapturingMetricExporter();
+
+        var builder = WebApplication.CreateBuilder();
+        builder.AddZbTelemetry(o =>
+        {
+            o.ServiceName = "t";
+            o.SiteId = "site-test";
+            o.NodeRole = "central";
+            o.Meters = ["Test.Meter"];
+        });
+
+        // Compose a capturing reader onto the pipeline AddZbTelemetry already registered.
+        builder.Services.ConfigureOpenTelemetryMeterProvider(b =>
+            b.AddReader(new PeriodicExportingMetricReader(capture)
+            {
+                TemporalityPreference = MetricReaderTemporalityPreference.Cumulative,
+            }));
+
+        // Create the meter + instrument BEFORE the provider is built so the MeterProvider's
+        // listener subscribes to it during construction.
+        using var meter = new Meter("Test.Meter");
+        var counter = meter.CreateCounter<long>("test.events.count");
+
+        using var app = builder.Build();
+
+        var meterProvider = app.Services.GetRequiredService<MeterProvider>();
+        counter.Add(1);
+        meterProvider.ForceFlush();
+
+        // The app's meter was registered and its instrument was collected through the pipeline.
+        Assert.Contains("test.events.count", capture.MetricNames);
+
+        // The exported metric carries the shared Resource (identical to ZbResource.Build).
+        Assert.NotNull(capture.CapturedResource);
+        var attrs = capture.CapturedResource!.Attributes.ToDictionary(a => a.Key, a => a.Value);
+        Assert.Equal("t", attrs["service.name"]);
+        Assert.Equal("ZB.MOM.WW", attrs["service.namespace"]);
+        Assert.Equal("site-test", attrs["site.id"]);
+        Assert.Equal("central", attrs["node.role"]);
+        Assert.Equal(Environment.MachineName, attrs["host.name"]);
+    }
+
+    /// <summary>
+    /// Collects exported metric names and captures the MeterProvider Resource on first export so
+    /// the test can assert the pipeline wired both the app meter and the shared Resource.
+    /// </summary>
+    private sealed class CapturingMetricExporter : BaseExporter<Metric>
+    {
+        public List<string> MetricNames { get; } = [];
+        public Resource? CapturedResource { get; private set; }
+
+        public override ExportResult Export(in Batch<Metric> batch)
+        {
+            CapturedResource ??= ParentProvider?.GetResource();
+            foreach (var metric in batch)
+            {
+                MetricNames.Add(metric.Name);
+            }
+
+            return ExportResult.Success;
+        }
+    }
+}