Simple request telemetry names

SimpleRequestTelemetryNameActionFilter.cs

#nullable enable
using System;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;

namespace Digma.Api.Common.Telemetry
{
    /// <summary>
    /// Action filter to construct a simpler telemetry name from the route name or the route template.
    /// <br/><br/>
    /// Out of the box, Application Insights sometimes uses request telemetry names like "GET /chat/ba1ce6bb-01e8-4633-918b-08d9a363a631/since/2021-11-18T18:51:08".
    /// This makes it hard to see how many requests were for a particular API action.
    /// This is a <a href="https://github.com/microsoft/ApplicationInsights-dotnet/issues/1418">known issue</a>.
    /// <br/><br/>
    /// - If route name is defined, then use that.<br/>
    /// - If route template is defined, then the name is formatted as "{method} /{template} v{version}".
    /// </summary>
    /// <example>
    /// - <b>"MyCustomName"</b> if route name is explicitly defined with <c>[Route("my_path", Name="MyCustomName")]</c><br/>
    /// - <b>"GET /config v2.0"</b> if template is "config" and API version is 2.0.<br/>
    /// - <b>"GET /config"</b> if no API version is defined.
    /// </example>
    /// <remarks>
    /// The value is passed on via <see cref="HttpContext.Items"/> with the key <see cref="SimpleRequestTelemetryNameInitializer.TelemetryNameKey"/>.
    /// </remarks>
    public class SimpleRequestTelemetryNameActionFilter : ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext context)
        {
            var httpContext = context.HttpContext;
            var attributeRouteInfo = context.ActionDescriptor.AttributeRouteInfo;

            if (attributeRouteInfo?.Name is { } name)
            {
                // If route name is defined, it takes precedence.
                httpContext.Items.Add(SimpleRequestTelemetryNameInitializer.TelemetryNameKey, name);
            }
            else if (attributeRouteInfo?.Template is { } template)
            {
                // Otherwise, use the route template if defined.
                string method = httpContext.Request.Method;
                string versionSuffix = GetVersionSuffix(httpContext);

                httpContext.Items.Add(SimpleRequestTelemetryNameInitializer.TelemetryNameKey, $"{method} /{template}{versionSuffix}");
            }

            base.OnActionExecuting(context);
        }

        private static string GetVersionSuffix(HttpContext httpContext)
        {
            try
            {
                var requestedApiVersion = httpContext.GetRequestedApiVersion()?.ToString();

                // Add leading whitespace so we can simply append version string to telemetry name.
                if (!string.IsNullOrWhiteSpace(requestedApiVersion))
                    return $" v{requestedApiVersion}";
            }
            catch (Exception)
            {
                // Some requests lack the IApiVersioningFeature, like requests to get swagger doc
            }

            return string.Empty;
        }
    }
}

SimpleRequestTelemetryNameInitializer.cs

using Microsoft.ApplicationInsights.Channel;
using Microsoft.ApplicationInsights.DataContracts;
using Microsoft.ApplicationInsights.Extensibility;
using Microsoft.AspNetCore.Http;

namespace Digma.Api.Common.Telemetry
{
    /// <summary>
    /// Changes the name of request telemetry to the value assigned by <see cref="SimpleRequestTelemetryNameActionFilter"/>.
    /// </summary>
    /// <remarks>
    /// The value is passed on via <see cref="HttpContext.Items"/> with the key <see cref="TelemetryNameKey"/>.
    /// </remarks>
    public class SimpleRequestTelemetryNameInitializer : ITelemetryInitializer
    {
        internal const string TelemetryNameKey = "SimpleOperationNameInitializer:TelemetryName";
        private readonly IHttpContextAccessor _httpContextAccessor;

        public SimpleRequestTelemetryNameInitializer(IHttpContextAccessor httpContextAccessor)
        {
            _httpContextAccessor = httpContextAccessor;
        }

        public void Initialize(ITelemetry telemetry)
        {
            var httpContext = _httpContextAccessor.HttpContext;
            if (telemetry is RequestTelemetry requestTelemetry && httpContext != null)
            {
                if (httpContext.Items.TryGetValue(TelemetryNameKey, out var telemetryNameObj)
                    && telemetryNameObj is string telemetryName
                    && !string.IsNullOrEmpty(telemetryName))
                {
                    requestTelemetry.Name = telemetryName;
                }
            }
        }
    }
}

Startup.cs

namespace Foo
{
    public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            // Register telemetry initializer.
            services.AddApplicationInsightsTelemetry();
            services.AddSingleton<ITelemetryInitializer, SimpleRequestTelemetryNameInitializer>();

            services.AddMvc(opt =>
            {
                // Global MVC filters.
                opt.Filters.Add<SimpleRequestTelemetryNameActionFilter>();
            });
        }

        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            // ...other configuration
        }
    }
}

@angularsen Can you share proper example. I have tried implementing your code but it is not working.

what should I write in place of "SimpleOperationNameInitializer:TelemetryName" ? its Name or key ?

@jigarce That is a just a unique string to store the value in HttpContext.Items, you don't need to change it.

I can't see any missing pieces here although I had to adapt from our code base.

Make sure you register everything as described in Startup.cs example.

I think you just have to debug a bit:

• Is SimpleRequestTelemetryNameActionFilter.OnActionExecuting() run as part of your API request? Does it compute the simplified name and store it in HttpContext.Items?
• Is SimpleRequestTelemetryNameInitializer.Initialize() run after the request? What values does it get?