The Azure App Service engineering team is always striving to improve the efficiency and overall performance of applications on our platform. Today, we are happy to announce Windows Server 2019 Container support in public preview.

To our customers, this expanded support translates into clear efficiencies:

Reduced container size enables you to be more cost effective by running more applications/slots within your App Service Plan. For example, the Windows Server Core 2019 LTSC base image is 4.28 GB compared to the Windows Server Core 2016 LTSC image is 11GB, which equates to a decrease of 61 percent!

You will benefit from faster startup time for your application because the container images will be smaller.

The container hosts have been updated to support Windows Server 2019, which means we can now support Windows Containers based on:

Windows Server Core 2019 LTSC

Windows Server Nano 1809

Windows Server Core 2016 1803

Windows Server Core 2016 1709

Windows Server Core 2016 LTSC

Windows Container support is available in our West US, East US, West Europe, North Europe, East Asia, and East Australia regions. Windows Containers are not supported in App Service Environments at present.

Faster app startup times with new, cache-based images

App Service caches several base images and we advise customers to use those images as the base of their containers to enable faster application startup times. Customers are free to use their own base images, though using non-cached base images will lead to longer application startup times.

Customers deploying .NET Framework Applications must choose a base image based on the Windows Server Core 2019 Long Term Servicing Channel release or older, and customers deploying .NET Core Applications must choose a base image based on Windows Server Nano 1809.

Cached base images:

mcr.microsoft.com/dotnet/framework/aspnet:4.7.2-windowsservercore-ltsc2019

mcr.microsoft.com/windows/nanoserver:1809

Resources

We want to hear from you!

Windows Container support for Azure App Service provides you with even more ways to build, migrate, deploy, and scale enterprise grade web and API applications running on the Windows platform. We are planning to add even more capabilities during the public preview and are very interested in your feedback as we move towards general availability.