From 7ff7a60ae089a84050ff3de5bfad0a7d831f9ca3 Mon Sep 17 00:00:00 2001
From: Joseph Doherty <dohejw01@gmail.com>
Date: Mon, 1 Jun 2026 16:40:24 -0400
Subject: [PATCH] feat(otopcua): config-driven OTLP exporter opt-in (default
 Prometheus)

---
 .../Observability/ObservabilityExtensions.cs       | 14 +++++++++++++-
 src/Server/ZB.MOM.WW.OtOpcUa.Host/Program.cs       |  2 +-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.Host/Observability/ObservabilityExtensions.cs b/src/Server/ZB.MOM.WW.OtOpcUa.Host/Observability/ObservabilityExtensions.cs
index 9257cdf6..34f0d665 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.Host/Observability/ObservabilityExtensions.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.Host/Observability/ObservabilityExtensions.cs
@@ -1,3 +1,4 @@
+using Microsoft.Extensions.Configuration;
 using ZB.MOM.WW.OtOpcUa.Commons.Observability;
 using ZB.MOM.WW.Telemetry;
 
@@ -14,13 +15,24 @@ public static class ObservabilityExtensions
 {
     /// <summary>Adds OtOpcUa observability (metrics and tracing) to the service collection.</summary>
     /// <param name="services">The service collection to add observability services to.</param>
-    public static IServiceCollection AddOtOpcUaObservability(this IServiceCollection services)
+    /// <param name="configuration">
+    /// Configuration read for the opt-in OTLP exporter. <c>OtOpcUa:Telemetry:Exporter</c>
+    /// (parsed case-insensitively to <see cref="ZbExporter"/>) switches to OTLP when set to
+    /// <c>Otlp</c>; <c>OtOpcUa:Telemetry:OtlpEndpoint</c> sets the OTLP endpoint. With no
+    /// config the exporter stays Prometheus (the default).
+    /// </param>
+    public static IServiceCollection AddOtOpcUaObservability(this IServiceCollection services, IConfiguration configuration)
     {
         return services.AddZbTelemetry(o =>
         {
             o.ServiceName = "otopcua";
             o.Meters = [OtOpcUaTelemetry.MeterName];
             o.ActivitySources = [OtOpcUaTelemetry.ActivitySourceName];
+            if (Enum.TryParse<ZbExporter>(configuration["OtOpcUa:Telemetry:Exporter"], ignoreCase: true, out var exporter))
+                o.Exporter = exporter;
+            var otlp = configuration["OtOpcUa:Telemetry:OtlpEndpoint"];
+            if (!string.IsNullOrWhiteSpace(otlp))
+                o.OtlpEndpoint = otlp;
         });
     }
 
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.Host/Program.cs b/src/Server/ZB.MOM.WW.OtOpcUa.Host/Program.cs
index 9ae0abb7..f0bacbd0 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.Host/Program.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.Host/Program.cs
@@ -135,7 +135,7 @@ if (hasAdmin)
 }
 
 builder.Services.AddOtOpcUaHealth();
-builder.Services.AddOtOpcUaObservability();
+builder.Services.AddOtOpcUaObservability(builder.Configuration);
 
 var app = builder.Build();
 app.UseSerilogRequestLogging();