Program.cs

using Prometheus;
using System.Net;

// This sample demonstrates how to integrate prometheus-net into a console app (e.g. a worker service) in a manner
// that does not require the ASP.NET Core runtime to be installed, as may be the case in some special hosting environments.
// 
// NuGet packages required:
// * prometheus-net

// Start the metrics server on your preferred port number.
using var server = new MetricServer(port: 1234);

try
{
    server.Start();
}
catch (HttpListenerException ex)
{
    Console.WriteLine($"Failed to start metric server: {ex.Message}");
    Console.WriteLine("You may need to grant permissions to your user account if not running as Administrator:");
    Console.WriteLine("netsh http add urlacl url=http://+:1234/metrics user=DOMAIN\\user");
    return;
}

// Generate some sample data from fake business logic.
var recordsProcessed = Metrics.CreateCounter("sample_records_processed_total", "Total number of records processed.");

_ = Task.Run(async delegate
{
    while (true)
    {
        // Pretend to process a record approximately every second, just for changing sample data.
        recordsProcessed.Inc();

        await Task.Delay(TimeSpan.FromSeconds(1));
    }
});

// Metrics published in this sample:
// * built-in process metrics giving basic information about the .NET runtime (enabled by default)
// * metrics from .NET Event Counters (enabled by default, updated every 10 seconds)
// * metrics from .NET Meters (enabled by default)
// * the custom sample counter defined above
Console.WriteLine("Open http://localhost:1234/metrics in a web browser.");
Console.WriteLine("Press enter to exit.");
Console.ReadLine();