Logging Request and response to Application Insight - azure-application-insights

Question

I'm trying to log API request payload and response data to Azure Application Insight. Using trace I can able to log. but I want to know what is the best way to log request and response data to application insight. Because data is huge, no.of API calls will be more. I can't just trace hundreds of thousands of request and response data using tracing. I tried some of the blogs like using ITelemetryInitializer/ httpcontext.feature,get, but no luck.
I want to log from c# .Net framework, Web API, not .NET Core.
Sample code which I tried.
public class AzureRequestResponseInitializer : ITelemetryInitializer
{
public void Initialize(ITelemetry telemetry)
{
var requestTelemetry = telemetry as RequestTelemetry;
if (requestTelemetry != null && (HttpContext.Current.Request.HttpMethod == HttpMethod.Post.ToString() || HttpContext.Current.Request.HttpMethod == HttpMethod.Get.ToString()))
{
using (var reader = new StreamReader(HttpContext.Current.Request.InputStream))
{
string requestBody = reader.ReadToEnd();
requestTelemetry.Properties.Add("body", requestBody);
}
}

Answer 1

You can achieve it by implementing IHttpModule that using Application Insight's TelemtryClient, see the following code:
using Microsoft.ApplicationInsights;
using Microsoft.ApplicationInsights.DataContracts;
using Contoso.Services.Logging.Extensions;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;
namespace Contoso.Services.Logging.Modules
{
public class CaptureTrafficModule : IHttpModule
{
public TelemetryClient Telemetry { get; set; }
public void Init(HttpApplication context)
{
context.BeginRequest += new EventHandler(context_BeginRequest);
context.EndRequest += new EventHandler(context_EndRequest);
Telemetry = new TelemetryClient();
}
void context_BeginRequest(object sender, EventArgs e)
{
HttpApplication app = sender as HttpApplication;
HttpResponse response = HttpContext.Current.Response;
OutputFilterStream filter = new OutputFilterStream(response.Filter);
response.Filter = filter;
app.Context.Items["Filter"] = filter;
StringBuilder request = new StringBuilder();
// Write All The Headers too :
//foreach (string key in app.Request.Headers.Keys)
//{
// request.Append(key);
// request.Append(": ");
// request.Append(app.Request.Headers[key]);
// request.Append("\n");
//}
//request.Append("\n");
byte[] bytes = app.Request.BinaryRead(app.Request.ContentLength);
if (bytes.Count() > 0)
request.Append(Encoding.ASCII.GetString(bytes));
app.Request.InputStream.Position = 0;
string operationName = $"{app.Request.HttpMethod} {app.Request.FilePath}";
string activityId = System.Diagnostics.Activity.Current.RootId;
app.Context.Items["OperationName"] = operationName;
app.Context.Items["ActivityId"] = activityId;
using (var logRequest = Telemetry.StartOperation<RequestTelemetry>(operationName, System.Diagnostics.Activity.Current.RootId, System.Diagnostics.Activity.Current.RootId))
{
try
{
//logRequest.Telemetry.Id = $"10-{activityId}";
logRequest.Telemetry.Url = app.Request.Url;
logRequest.Telemetry.Properties["RequestBody"] = request.ToString();
}
catch (Exception ex)
{
logRequest.Telemetry.Success = false;
Telemetry.TrackException(ex);
//throw;
}
}
}
void context_EndRequest(object sender, EventArgs e)
{
HttpApplication app = sender as HttpApplication;
OutputFilterStream filter = null;
string operationName = "", activityId = Guid.Empty.ToString(), responseStr = "NONE";
if (app.Context.Items.Contains("OperationName"))
operationName = app.Context.Items["OperationName"].ToString();
if (app.Context.Items.Contains("ActivityId"))
activityId = app.Context.Items["ActivityId"].ToString();
if (app.Context.Items.Contains("Filter"))
{
filter = (OutputFilterStream)app.Context.Items["Filter"];
responseStr = filter.ReadStream();
}
using (var logResponse = Telemetry.StartOperation<RequestTelemetry>(operationName, activityId, activityId))
{
try
{
//logResponse.Telemetry.Id = $"20-{activityId}";
logResponse.Telemetry.Url = app.Request.Url;
logResponse.Telemetry.Properties["ResponseBody"] = responseStr.ToString();
}
catch (Exception ex)
{
logResponse.Telemetry.Success = false;
Telemetry.TrackException(ex);
//throw;
}
}
}
public void Dispose()
{
//Does nothing
}
}
}

Answer 2

This question is answered in https://thirum.wordpress.com/2019/08/19/logging-the-http-response-body-in-application-insights/
Please take a look.