Program.cs

// <copyright file="Program.cs" company="OpenTelemetry Authors">
// Copyright The OpenTelemetry Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// </copyright>

using System.Diagnostics;
using OpenTelemetry.Metrics;
using OpenTelemetry.Resources;

var appBuilder = WebApplication.CreateBuilder(args);

// Configure OpenTelemetry with metrics and auto-start.
appBuilder.Services.AddOpenTelemetry()
    .ConfigureResource(builder => builder
        .AddService(serviceName: "OTel.NET Getting Started"))
    .WithMetrics(builder => builder
        .AddAspNetCoreInstrumentation()
        .AddConsoleExporter((exporterOptions, metricReaderOptions) =>
        {
            metricReaderOptions.PeriodicExportingMetricReaderOptions.ExportIntervalMilliseconds = 1000;
        }));

var app = appBuilder.Build();

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

app.Run();