Today, the Azure Functions team announced the public preview of Azure Functions version 4.0. The most notable feature of this new runtime is support for .NET 6.0.
Update: Azure Functions 4.0 with .NET 6 support is now generally available!
Getting started with .NET 6 on Azure Functions
Azure Functions has two programming models for .NET—in-process and isolated process.
With the in-process programming model and Azure Functions 4.0, you can write .NET 6 function apps that take advantage of advanced features such as Durable Functions. See the documentation to learn more:
.NET 6 is also supported in Azure Functions 4.0 using the isolated process programming model. The isolated model gives you full control over the language worker startup configuration and provides useful features like dependency injection and middleware. Currently, you can use the command line to create and deploy your .NET 6 isolated apps. .NET 6 isolated process support is coming soon to Visual Studio and Visual Studio Code.
While the new runtime is currently in preview, you won't have to wait long to run .NET 6 function apps in production. Azure Functions 4.0 is expected to be generally available when .NET 6 LTS is released in early November.
Migrating your apps to Azure Functions 4.0 preview
The 4.0 runtime supports all Azure Functions languages. To run your apps locally on the preview runtime, download Azure Functions Core Tools 4.0 preview. See the Azure Functions versions documentation to learn more about what’s new in the 4.0 preview and how to migrate your apps.
Also, watch for a new Azure Functions Live webcast coming soon to YouTube and Microsoft Learn TV.
Staying up-to-date
The Azure Functions host and language workers will continue to evolve during the preview period. There's a list of planned breaking changes. You'll also want to make sure to subscribe to App Service Announcements for notifications on breaking changes and how to mitigate them.
Updates
September 22, 2021 22:41UTC – Added "Staying up-to-date" section
November 16, 2021 23:00UTC – Adding link to GA announcement