Microsoft previews Linux containers that run in Windows

Now not only can you run Linux from within Windows without third-party tools, but can do so within containers. Microsoft has continued the trend of the Windows Subsystem for Linux (WSL) being one of the company's more interesting developer technologies with the arrival of a public preview of WSL containers.

According to Microsoft, the update adds a pair of new features to WSL: "A built in Linux container CLI and an API for Windows applications to run Linux containers as part of their app logic."

Microsoft senior project manager Craig Loewen said, "this CLI tool has a familiar format and capabilities," and indeed it does. If Docker is something you know, the wslc.exe syntax (wslc.exe is the new binary) will be very familiar. There's also a built-in alias for container.exe for users who prefer to type container instead of wslc.

"Containers," said Loewen, "have become a foundational part of modern development – from cloud-native applications and AI workloads to testing and deployment pipelines.

"WSL containers simplify this experience by providing a built-in, enterprise-ready way to create, run, and manage Linux containers on Windows, without requiring additional third-party tooling."

WSL has always been a handy way to run Linux workloads from Windows, and is particularly convenient for Linux developers who must comply with corporate edicts to use a Windows device. The CLI for end-to-end container workflows furthers this. Microsoft stated, "WSL containers make it easier for developers and organizations to build, test, and run containerized workloads while benefiting from the security, manageability, and integration of the Windows platform."

Alternatively, you could run your preferred Linux distribution natively, but that might not be an option, particularly if an organization is keen on the "security, manageability, and integration of the Windows platform."

And this is an important point. WSL's existing Microsoft Defender for Endpoint (MDE) has been updated (in private preview) to be aware of Linux container events, and there are settings in Intune for managing WSL containers. Support is also in a pre-release version of VS Code, where the Docker path in the dev container settings can be changed to wslc.

There is also a new default file system for WSL container that Microsoft claims makes Windows file access twice the speed. So, going from terribly slow to just slow? We'll wait until general availability is reached before passing judgment. There's a new default networking mode to improve compatibility and better memory reclaim techniques.

However, none of these tweaks will be enabled by default in WSL. Microsoft wrote, "Since these changes touch mission critical paths like file system access and network, for now they are enabled just in WSL container."

The company is also at pains to point out that this is currently in public preview, although things seemed quite solid in the version we downloaded to try. That said, relying on this for any serious work would be foolhardy in the extreme, but it is certainly worth trying out ahead of general availability later this year. ®