Missing Functions in isolated worker function app

Question

Hello!

I upgraded from an in-process modell to isolated worker.
After the deployment everything worked and the functions were able to be invoked, but I got an error message saying: Referenced bundle Microsoft.Azure.Functions.ExtensionBundle of version 1.8.1 does not meet the required minimum version of 2.6.1.
So I added the extension bundle in the host.json:

  "extensionBundle": {
    "id": "Microsoft.Azure.Functions.ExtensionBundle",
    "version": "[4.*, 5.0.0)"
  }

After redeploying the function app, all functions went missing and could not be invoked anymore.

Answer 1

Hello @Eberl Sebastian !

Thank you for posting on Microsoft Learn.

In Azure Functions isolated worker model, especially for .NET (and similarly structured for other languages), the extension bundle is not required or not supported in the same way as in-process functions.

The line you added is applicable to in-process models and may break isolated worker functions, which load their own dependencies explicitly via NuGet.

Your host.json should not include any extensionBundle block in isolated mode :

{
  "version": "2.0",
  "logging": {
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": true
      }
    }
  }
}

In the isolated model, each extension must be explicitly referenced via NuGet :

<PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="1.13.0" OutputItemType="Analyzer" />
<PackageReference Include="Microsoft.Azure.Functions.Worker" Version="1.13.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http" Version="3.1.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Storage.Queues" Version="5.0.0" />