Deploying dotnet-isolated function app from CLI

Whether you’re creating a brand-new .NET isolated function app or migrating an existing one, if you’re deploying it using the Azure Functions Core Tools, you might encounter this error:

Your Azure Function App has 'FUNCTIONS_WORKER_RUNTIME' set to 'dotnetIsolated' while your local project is set to 'dotnet'.
You can pass --force to update your Azure app with 'dotnet' as a 'FUNCTIONS_WORKER_RUNTIME'

The suggestion would do the exact opposite of what we want to achieve!

There is an undocumented flag --dotnet-isolated that you can use to specify the dotnet worker runtime, which combined with --force will ensure the app is updated to use that runtime too, just in case:

func azure functionapp publish <FunctionAppName> --dotnet-isolated --force

Alternatively, you can use the officially documented --worker-runtime dotnet-isolated flag to specify the runtime.

It’s quite bad that running the CLI with --help returns no information about this flag and many others. It’s hopelessly out of sync with the docs.

Enjoy!