Program.cs

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

using OpenTelemetry.Metrics;
using OpenTelemetry.Resources;

var builder = WebApplication.CreateBuilder(args);

// Configure OpenTelemetry with metrics and auto-start.
builder.Services.AddOpenTelemetry()
    .ConfigureResource(resource => resource
        .AddService(serviceName: builder.Environment.ApplicationName))
    .WithMetrics(metrics => metrics
        .AddAspNetCoreInstrumentation()
        .AddConsoleExporter((exporterOptions, metricReaderOptions) =>
        {
            metricReaderOptions.PeriodicExportingMetricReaderOptions.ExportIntervalMilliseconds = 1000;
        }));

var app = builder.Build();

app.MapGet("/", () => $"Hello from OpenTelemetry Metrics!");

app.Run();