Almost a year ago, Microsoft launched a preview of Windows Server Containers in Azure Kubernetes Service (AKS). Now the company announced the general availability of Windows Server containers in AKS, including the support of private clusters and managed identities.
With the GA of Windows Server containers, enterprises can now lift-and-shift their Windows applications to run on managed kubernetes services in Azure. Moreover, developers in these enterprises can create, upgrade, and scale Windows node pools in AKS through the standard tools such as the Azure Portal or Command Line Interface (CLI) - Azure will help manage the health of the cluster automatically.
Furthermore, Windows and Linux applications can run in parallel on a single AKS cluster – which makes it easier for enterprises to bundle their applications for business processes. Microsoft corporate vice president, Azure Compute Brendan Burns wrote in his blog post on the GA release:
Running both Windows and Linux applications side by side in a single AKS cluster, you can modernize your operations processes for a broader set of applications while increasing the density (and thus lowering the costs) of your application environment.
And Elton Stoneman, Microsoft Azure MVP and Docker Captain, told InfoQ:
It's fantastic to see Windows nodes reach General Availability in AKS - it's a real milestone in the journey towards moving all your apps into containers and onto the cloud. Kubernetes uses the same application manifest language for Windows and Linux apps, so you get a layer of consistency across all your applications. Older .NET Framework apps and new apps written in .NET Core or Go or Node.js all have the same artifacts to build and run them: Dockerfiles and Kubernetes manifests. You can develop and deploy all your apps using GitHub actions, publishing your images to the Azure Container Registry and deploying to AKS with the same simple workflows.
Microsoft is not the only public cloud vendor with Kubernetes services and support for Windows Containers. For instance, Amazon announced the general availability of Windows Container on Elastic Kubernetes Service (EKS) in October last year; however, it has some limitations. Also, Google brought the support of Windows Containers to its Google Kubernetes Engine (GKE) in preview at the beginning of this year and recently became ga.
Stoneman also told InfoQ:
I have been working with clients using Windows nodes in AKS under the preview release for several months now, and it has been very solid and easy to use. Lots of organizations have a roadmap for their Windows apps which starts by moving them to containers as-is with no code changes and then gradually breaking them up into distributed applications. Now with Windows nodes GA in AKS, that is a fully supported path in Azure. You can start by shifting .NET Framework monoliths into Windows pods, and incrementally split features out into .NET Core apps running in Linux pods, all on the same AKS cluster.
Besides the support for Windows Containers in AKS, Microsoft also announced support for private clusters and managed identities – which are intended to provide developers with greater security capabilities and to easier meet compliance requirements. Private clusters allow the use of managed Kubernetes within a closed network - without connection to the internet. And, with private clusters, the security measures of highly regulated industries such as finance or healthcare can be met.
Next to the support for private clusters, AKS supports managed identities, which enables secure interaction with other Azure services such as Azure Monitor for Containers or Azure Policy. Furthermore, developers do not have to manage their service principals or rotate credentials often.
Lastly, Burns wrote in his blog post about the continuous development of more integrations between AKS and Azure Advisor and bringing industry best practices right into the AKS experience. Moreover, Microsoft is committed to bringing customer learning into the VS Code extension for Kubernetes to provide developers with advice and integrate security advice into the Azure Security Center. Developers, operator, and architects can, according to Burns, be successful with Kubernetes on Azure through the available learning, frameworks, and tools.