How do I use external assemblies with Microsoft Azure Function Apps?

Question

The documentation says that you can put a DLL in a bin folder and reference it using a special #r syntax, however in the Azure portal I cannot find how to upload these DLLs. Is this possible, and if so, how is that supposed to be accomplished?

Answer 1

This is possible.

You can use Kudu to upload your binaries:

1. Open the app's Kudu portal. If your Functions App's URL is samplefunctions.azurewebsites.net, then go to samplefunctions.scm.azurewebsites.net.

2. Click on the Debug console menu and select PowerShell. This will open up a PowerShell console plus a file explorer. Navigate to D:\home\site\wwwroot.

3. There you should see a folder which is named after your existing function. Navigate to that folder and drag-n-drop your binaries inside bin folder.

4. Now you can use them with #r directive.

I think you should also be able to configure the continuous deployment of your libraries to Functions (e.g. from a Git repo). Go to Function app settings -> Configure Continuous Integration.

Answer 2

Azure functions now has runtime support for precompiled functions. https://blogs.msdn.microsoft.com/appserviceteam/2017/03/16/publishing-a-net-class-library-as-a-function-app/

You’ll need to use a web project which will provide the full development experience of IntelliSense, local debugging, and publishing to Azure. The instructions above detail how.