ApplicationInsightsMiddleware.cs

using System;
using System.Threading.Tasks;
using Microsoft.ApplicationInsights;
using Microsoft.ApplicationInsights.DataContracts;
using Microsoft.ApplicationInsights.Extensibility;
using Microsoft.AspNetCore.Http;
using Proposta.API.Utils;
using Proposta.Shared.Interfaces;

namespace Proposta.API
{
    public class ApplicationInsightsMiddleware
    {
        private readonly RequestDelegate next;
        private TelemetryClient telemetryClient;
        private ITelemetryLogClient logClient;

        public ApplicationInsightsMiddleware(RequestDelegate next, TelemetryClient telemetryClient, ITelemetryLogClient logClient)
        {
            this.telemetryClient = telemetryClient;
            this.next = next;
            this.logClient = logClient;
        }

        public async Task InvokeAsync(HttpContext context)
        {
            // Let's create and start RequestTelemetry.
            var requestTelemetry = new RequestTelemetry
            {
                Name = $"{context.Request.Method} {context.Request.Path}"
            };

            // If there is a Request-Id received from the upstream service, set the telemetry context accordingly.
            if (context.Request.Headers.ContainsKey("Request-Id"))
            {
                var requestId = context.Request.Headers["Request-Id"];
                // Get the operation ID from the Request-Id (if you follow the HTTP Protocol for Correlation).
                requestTelemetry.Context.Operation.Id = GetOperationId(requestId);
                requestTelemetry.Context.Operation.ParentId = requestId;
            }
            if (context.Request.Headers.ContainsKey("idUsuario"))
            {
                var user = context.Request.Headers["idUsuario"];
                // Get the operation ID from the Request-Id (if you follow the HTTP Protocol for Correlation).
                requestTelemetry.Context.User.Id = user;
            }

            requestTelemetry.Properties.Add("query", context.Request.QueryString.ToString());
            
            // StartOperation is a helper method that allows correlation of 
            // current operations with nested operations/telemetry
            // and initializes start time and duration on telemetry items.
            var operation = telemetryClient.StartOperation(requestTelemetry);

            // Process the request.
            try
            {
                await next.Invoke(context);
            }
            catch (Exception e)
            {
                await PropostaExceptionHandler.HandleException(context, logClient, e);
                requestTelemetry.Success = false;;
            }
            finally
            {
                // Update status code and success as appropriate.
                if (context.Response != null)
                {
                    requestTelemetry.ResponseCode = context.Response.StatusCode.ToString();
                    requestTelemetry.Success = context.Response.StatusCode >= 200 && context.Response.StatusCode <= 299;
                }
                else
                {
                    requestTelemetry.Success = false;
                    
                }

                // Now it's time to stop the operation (and track telemetry).
                telemetryClient.StopOperation(operation);
            }
        }
        
        public static string GetOperationId(string id)
        {
            // Returns the root ID from the '|' to the first '.' if any.
            int rootEnd = id.IndexOf('.');
            if (rootEnd < 0)
                rootEnd = id.Length;

            int rootStart = id[0] == '|' ? 1 : 0;
            return id.Substring(rootStart, rootEnd - rootStart);
        }
    }
}