How to set the cloud_roleName for Application Insights for .NET Core?

Question

I am trying to set the cloud_RoleName property to disambiguate different components in a system tracked with Azure Application Insights.

How can I set the property for services running with ASP.NET Core?

Answer 1

RoleNames are by default populated. Is that not the case you observe or you want to override the behaviour? To override the rolename, the following should help:

Write a TelemetryInitializer like the one below to populate RoleName to your desired value.

public class MyRoleNameInitializer : ITelemetryInitializer  
 {
      public void Initialize(ITelemetry telemetry)
        {
           telemetry.Context.Cloud.RoleName = "MyCustomRoleName";
        }
 }

Then add the following line to add the TelemetryInitializer to the configuration, in the ConfigureServices method of you application startup class.

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc();
        services.AddSingleton<ITelemetryInitializer, MyRoleNameInitializer>();
    }

Note: If you used AddApplicationInsightsTelemetry() in the ConfigureServices of your Startup class to add Application Insights, then the above line should be done before AddApplicationInsightsTelemetry() as shown below.

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc();
        services.AddSingleton<ITelemetryInitializer, MyRoleNameInitializer>();
        services.AddApplicationInsightsTelemetry("ikey");
    }