This service descriptor is keyed. Your service provider may not support keyed services

Question

I have a .Net 8 Isolated Functions app to which I have added Application Insights. Here is my host builder code.

    var host = new HostBuilder()
        .ConfigureFunctionsWebApplication()
        .ConfigureServices((context, services) =>
        {
            services.AddApplicationInsightsTelemetryWorkerService();
            services.ConfigureFunctionsApplicationInsights();
        })
        .Build();

When the line services.AddApplicationInsightsTelemetryWorkerService(); executes I get the following exception...

System.InvalidOperationException
  HResult=0x80131509
  Message=This service descriptor is keyed. Your service provider may not support keyed services.
  Source=Microsoft.Extensions.DependencyInjection.Abstractions
  StackTrace:
   at Microsoft.Extensions.DependencyInjection.ServiceDescriptor.ThrowKeyedDescriptor() in Microsoft.Extensions.DependencyInjection\ServiceDescriptor.cs:line 483

Can anyone tell me how I can fix this?

Answer 1

Application Insights is configured locally by default for .NET 8 Isolated Function.

• To work with Application Insights in the deployed function app you need to remove the local and Install the Azure Application Insights.

I am able to run the function with the default code and log traces to Application Insights without any issues.

My .csproj file:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
    <OutputType>Exe</OutputType>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
    <ApplicationInsightsResourceId>/subscriptions/******/resourceGroups/******/providers/microsoft.insights/components/FunctionApp1</ApplicationInsightsResourceId>
    <UserSecretsId>******</UserSecretsId>
  </PropertyGroup>
  <ItemGroup>
    <FrameworkReference Include="Microsoft.AspNetCore.App" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker" Version="1.20.1" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http" Version="3.1.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http.AspNetCore" Version="1.2.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="1.16.4" />
    <PackageReference Include="Microsoft.ApplicationInsights.WorkerService" Version="2.21.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.ApplicationInsights" Version="1.1.0" />
    <PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="8.0.0" />
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
  <ItemGroup>
    <Using Include="System.Threading.ExecutionContext" Alias="ExecutionContext" />
  </ItemGroup>
</Project>

My Program.cs file:

var host = new HostBuilder()
    .ConfigureFunctionsWebApplication()
    .ConfigureServices(services =>
    {
        services.AddApplicationInsightsTelemetryWorkerService();
        services.ConfigureFunctionsApplicationInsights();
    })
    .Build();

Local Output:

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