Docker wants to make Kubernetes management on a Windows desktop more robust—and easier. Docker’s recently introduced Windows Desktop 18.02 Edge release includes, among other features, an option to automate the installation of a Kubernetes cluster and better support for Linux containers.
“Kubernetes is an extremely powerful container orchestrator, and with that power comes complexity. To date that complexity has made it difficult for developers to host a Kubernetes cluster within their development environment, requiring the use of Kubernetes clusters hosted elsewhere, or being unable to develop in an environment that matches their integration, QA and production environments,” says Carl Fischer, Docker’s principal partner program manager. “This has increased the chances of defects or deployment issues. Docker for Windows solves those issues by providing a fully automated installation of a single-node Kubernetes cluster on the developer’s workstation.”
In the big picture sense, Fischer says improving Kubernete support for Windows is part of Docker’s mission to offer a wider range of Kubernete tools.
“Kubernetes has a rich and broad ecosystem. It’s important for developers to be able to reap the benefits of Docker while having access to the same Kubernetes tools they’ve grown to know and love when working with Kubernetes clusters hosted on their desktop,” he says. “Docker for Windows Desktop 18.02 provides that by including a Kubernetes client, integration with the Docker CLI and support for third-party tools.”
Docker for Windows has, of course, been around for a while. Initially, Windows 10 and Windows Server began to support Windows process-isolated and Hyper-V-isolated containers. Docker later released Docker for Windows Desktop, which supported a separate Linux mode option running Linux containers with a Hyper-V VM, as well as a Windows mode to run Windows containers with native Windows container features.
After Docker for Windows Desktop became available, Docker released experimental LCOW support for Dockers for Windows. The LCOW mode allowed Linux containers to run using native Windows container features, including Hyper-V isolation, instead of via a Hyper-V VM. “This was an intermediate step toward the most recent version of LCOW,” Fischer says. “The important takeaway is that Hyper-V-isolated containers are not full-blown Hyper-V VMs. Hyper-V isolated containers are smaller and faster than Hyper-V VMs are, and omit VM features that are not relevant in a container, such as support for various virtual or emulated devices, giving them a smaller attach surface.”
The recent Edge release of Docker for Windows Desktop 18.02 goes much further than the previous version of Windows Desktop did, of course, including its support for Linux containers on LCOW. As mentioned, it can be used to automate the installation of a Kubernetes cluster. A major feature also consists of the elimination of a separate LCOW mode so users can run both Linux and Windows containers using native Windows container features. This ability to run Docker Linux and Windows containers side-by-side, for example, will likely make life easier for many DevOps teams.
However, since Docker for Windows Desktop 18.02 is an Edge release, there will be the inevitable bugs and instability when giving it a test run, ahead of when the fully vetted Stable channel version will be available. Kubernetes support, among other new features for Windows containers, for example, is still under active development, Fischer says. However, he didn’t specify when the Stable channel release for the latest version of Docker for Windows Desktop will be available.
“Kubernetes support and LCOW have not yet converged [in a Stable channel release],” Fischer says. “So, Kubernetes support is only available when running in the traditional Docker for Windows Linux mode, and not in Windows mode via LCOW.”
If you want to give it a try, the Edge version of Windows Desktop 18.02 is available for download on desktops running the Enterprise version of Windows 10.