API Endpoints for open-telemetry/opentelemetry-dotnet

To understand the defined routes in the open-telemetry/opentelemetry-dotnet codebase, it is essential to focus on the framework’s structure, particularly in how it manages HTTP requests and routing within its various components.

Overview of Routes in the Codebase

Routes in this context are established primarily within the HTTP services and API endpoints utilized by the OpenTelemetry Collector for .NET. The routing structure typically resides in the project files where ASP.NET Core is leveraged for building out HTTP interfaces.

Example: HttpListener in OpenTelemetry

One of the key components that define routes is the HTTP listener. Below is an example showcasing how routes might be defined in a component that sets up an HTTP listener for telemetry data.

using System;
using System.Net;
using System.Text.Json;

public class TelemetryListener
{
private readonly HttpListener _listener = new HttpListener();
public TelemetryListener(string prefix)
{
_listener.Prefixes.Add(prefix);
_listener.Start();
}
public async Task ListenAsync()
{
while (_listener.IsListening)
{
var context = await _listener.GetContextAsync();
HandleRequest(context);
}
}
private void HandleRequest(HttpListenerContext context)
{
// Define routes based on request path
switch (context.Request.Url.AbsolutePath)
{
case "/v1/traces":
// Handle trace collection
context.Response.StatusCode = (int)HttpStatusCode.OK;
context.Response.Close();
break;
case "/v1/spans":
// Handle span data
context.Response.StatusCode = (int)HttpStatusCode.OK;
context.Response.Close();
break;
default:
context.Response.StatusCode = (int)HttpStatusCode.NotFound;
context.Response.Close();
break;
}
}
}

Example: ASP.NET Core Middleware

In ASP.NET Core applications, routing is often managed through middleware. Below is an example showcasing the route definition in the Startup configuration.

public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
}

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseRouting();
app.UseEndpoints(endpoints =>
{
endpoints.MapPost("/v1/traces", async context =>
{
var body = await new StreamReader(context.Request.Body).ReadToEndAsync();
// Process trace data...
context.Response.StatusCode = StatusCodes.Status200OK;
});
endpoints.MapPost("/v1/spans", async context =>
{
var body = await new StreamReader(context.Request.Body).ReadToEndAsync();
// Process span data...
context.Response.StatusCode = StatusCodes.Status200OK;
});
});
}
}

Summary of Defined Routes

1. Trace Collection Endpoint:

   • POST /v1/traces: Receives trace data for processing.

2. Span Data Endpoint:

   • POST /v1/spans: Receives span data for processing.

These examples illustrate the general approaches used to define routes within the codebase, focusing on how the OpenTelemetry libraries are designed to handle incoming telemetry data.

Source Reference

For further details on how these routes integrate into the overall architecture, refer to the source code available in the OpenTelemetry GitHub repository: open-telemetry/opentelemetry-dotnet