Use env var

dotnet · Jun 25, 2024 · 22fc06c · 22fc06c
1 parent f53b342
commit 22fc06c
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Showing 3 changed files with 7 additions and 1 deletion.
diff --git a/playground/TestShop/ServiceDefaults/Extensions.cs b/playground/TestShop/ServiceDefaults/Extensions.cs
@@ -48,7 +48,6 @@ public static IHostApplicationBuilder ConfigureOpenTelemetry(this IHostApplicati
         builder.Services.AddOpenTelemetry()
             .WithMetrics(metrics =>
             {
-                metrics.SetExemplarFilter(ExemplarFilterType.TraceBased);
                 metrics.AddAspNetCoreInstrumentation()
                        .AddHttpClientInstrumentation()
                        .AddRuntimeInstrumentation();

diff --git a/src/Aspire.Hosting/OtlpConfigurationExtensions.cs b/src/Aspire.Hosting/OtlpConfigurationExtensions.cs
@@ -76,6 +76,8 @@ public static void AddOtlpEnvironment(IResource resource, IConfiguration configu
 
                 // Configure trace sampler to send all traces to the dashboard.
                 context.EnvironmentVariables["OTEL_TRACES_SAMPLER"] = "always_on";
+                // Configure metrics to include exemplars.
+                context.EnvironmentVariables["OTEL_METRICS_EXEMPLAR_FILTER"] = "trace_based";
             }
         }));
 

diff --git a/tests/Aspire.Hosting.Tests/ProjectResourceTests.cs b/tests/Aspire.Hosting.Tests/ProjectResourceTests.cs
@@ -109,6 +109,11 @@ public async Task AddProjectAddsEnvironmentVariablesAndServiceMetadata()
                 Assert.Equal("always_on", env.Value);
             },
             env =>
+            {
+                Assert.Equal("OTEL_METRICS_EXEMPLAR_FILTER", env.Key);
+                Assert.Equal("trace_based", env.Value);
+            },
+            env =>
             {
                 Assert.Equal("DOTNET_SYSTEM_CONSOLE_ALLOW_ANSI_COLOR_REDIRECTION", env.Key);
                 Assert.Equal("true", env.Value);