Enable the .NET Profiler on Azure containers

You can enable the Application Insights Profiler for .NET on applications running in your container almost without code. To enable the .NET Profiler on your container instance, you need to:

• Add the reference to the Microsoft.ApplicationInsights.Profiler.AspNetCore NuGet package.
• Update the code to enable the Profiler for .NET.
• Set up the Application Insights connection string.

In this article, you learn about the various ways that you can:

Prerequisites

• An Application Insights resource. Make note of the connection string.
• Docker Desktop to build Docker images.
• .NET 6 SDK installed.

Set up the environment

1. Clone and use the following sample project:

   git clone https://github.com/microsoft/ApplicationInsights-Profiler-AspNetCore.git
   

2. Go to the Container App example:

   cd examples/EnableServiceProfilerForContainerAppNet6
   

3. This example is a barebones project created by calling the following CLI command:

   dotnet new mvc -n EnableServiceProfilerForContainerApp
   

   A delay is in the Controllers/WeatherForecastController.cs project to simulate the bottleneck.

   [HttpGet(Name = "GetWeatherForecast")]
   public IEnumerable<WeatherForecast> Get()
   {
       SimulateDelay();
       ...
       // Other existing code.
   }
   private void SimulateDelay()
   {
       // Delay for 500ms to 2s to simulate a bottleneck.
       Thread.Sleep((new Random()).Next(500, 2000));
   }
   

4. Add the NuGet package to collect the .NET Profiler traces:

   dotnet add package Microsoft.ApplicationInsights.Profiler.AspNetCore
   

5. Enable Application Insights and the .NET Profiler.

   • ASP.NET Core 6 and later
   • ASP.NET Core 5 and earlier

   Add builder.Services.AddApplicationInsightsTelemetry() and builder.Services.AddServiceProfiler() after the WebApplication.CreateBuilder() method in Program.cs:

   var builder = WebApplication.CreateBuilder(args);
   
   builder.Services.AddApplicationInsightsTelemetry(); // Add this line of code to enable Application Insights.
   builder.Services.AddServiceProfiler(); // Add this line of code to enable Profiler
   builder.Services.AddControllersWithViews();
   
   var app = builder.Build();
   

   You can also add custom Profiler settings, if applicable.

Pull the latest ASP.NET Core build/runtime images

1. Go to the .NET Core 6.0 example directory:

   cd examples/EnableServiceProfilerForContainerAppNet6
   

2. Pull the latest ASP.NET Core images:

   docker pull mcr.microsoft.com/dotnet/sdk:6.0
   docker pull mcr.microsoft.com/dotnet/aspnet:6.0
   

Add your Application Insights key

1. Via your Application Insights resource in the Azure portal, take note of your Application Insights connection string.

   

2. Open appsettings.json and add your Application Insights connection string to this code section:

   {
       "ApplicationInsights":
       {
           "InstrumentationKey": "Your connection string"
       }
   }
   

Build and run the Docker image

1. Review the Docker file.

2. Build the example image:

   docker build -t profilerapp .
   

3. Run the container:

   docker run -d -p 8080:80 --name testapp profilerapp
   

View the container via your browser

To hit the endpoint, you have two options:

• Visit http://localhost:8080/weatherforecast in your browser.

• Use curl:

  curl http://localhost:8080/weatherforecast
  

Inspect the logs

Optionally, inspect the local log to see if a session of profiling finished:

docker logs testapp

In the local logs, note the following events:

Starting application insights profiler with connection string: your-connection string # Double check the connection string
Service Profiler session started.               # Profiler started.
Finished calling trace uploader. Exit code: 0   # Uploader is called with exit code 0.
Service Profiler session finished.              # A profiling session is completed.

Troubleshooting

If you are unable to find traces from your app, consider following the steps in this troubleshooting guide.

View the .NET Profiler traces

1. Wait for 2 to 5 minutes so that the events can be aggregated to Application Insights.

2. Open the Performance pane in your Application Insights resource.

3. After the trace process is finished, the Profiler Traces button appears.

   

Clean up resources

Run the following command to stop the example project:

docker rm -f testapp

Next steps