Microsoft has been building its own Linux distributions to support its cloud services and developer tools. One of the key players is Azure Linux, also known as CBL-Mariner. This lightweight Linux version is designed specifically for Microsoft’s cloud infrastructure, including container platforms like Azure Kubernetes Service (AKS) and tools like Windows Subsystem for Linux (WSL). It’s built to be small, fast, and controlled by Microsoft, giving the company a reliable base for various projects.

What’s New in Azure Linux 3.0

Azure Linux 3.0 arrived in spring 2025 and is now used in AKS version 1.32 and above. It’s based on the Linux kernel 6.6 and runs on both x64 and Arm processors, including Azure’s high-density Arm systems. This update supports popular cloud-native tools like Dapr and Terraform, making it easier to build complex, scalable applications on Azure Linux 3.0.

The new release also includes updates to core components like ContainerD and SystemD. Plus, it adds support for the SymCrypt cryptography library, which is important for future security standards like post-quantum cryptography. Microsoft keeps the source code open on GitHub, so developers can download, modify, and build their own versions if needed. Containers based on Azure Linux 3.0 are available in Microsoft’s container registry, making deployment straightforward.

To enhance security, Microsoft has integrated Azure Linux with its OS Guard tool. This adds policy enforcement, trusted launch, and secure boot features. This means only trusted, verified code can run, reducing the risk of malware or unauthorized access. Azure Linux 3.0 will be supported until 2028, giving users plenty of time to plan migrations from older versions.

Building and Customizing Your Azure Linux

Microsoft provides detailed instructions on how to build Azure Linux from source. This allows organizations to create custom images with specific packages or internal tools. You can generate a bootable ISO or a virtual machine image for platforms like Hyper-V or KVM. Building from source is useful if you want a tailored environment, but it requires ongoing maintenance to keep security patches up to date.

For those who want to run Azure Linux in their workflows, it’s possible to use the project’s code to create custom images. This flexibility helps teams integrate Azure Linux into their existing infrastructure while maintaining control over the environment.

Running Azure Linux in Windows Subsystem for Linux

One exciting use case is running Azure Linux directly inside Windows using WSL. Although Azure Linux is distributed as an ISO or Docker container, Microsoft recently added support for tarball-based installs, making it easier to set up in WSL.

To do this, developers can pull the Azure Linux container image using tools like Podman or Docker in an existing Linux environment. They then export the container’s filesystem to a tarball and copy it into Windows. Using the WSL import command, this tarball can be transformed into a new Linux distribution inside Windows. It’s a quick way to get a lightweight Azure Linux environment running on your PC.

Once imported, you can launch the Azure Linux distribution from Windows Terminal or the command line. Although initial setup might generate some mount errors, these don’t affect the ability to experiment and develop. The environment can also be accessed via Windows File Explorer, making it easy to share files and work seamlessly across Windows and Linux.

Making Azure Linux Part of Your Development Setup

Running Azure Linux in WSL allows developers to build and test containerized applications without needing a full VM or cloud environment. It’s lightweight, quick to start, and integrates well with tools like Visual Studio Code. You can also use it to simulate cloud environments locally, helping streamline development workflows.

For those managing larger projects, deploying Azure Linux as a virtual machine remains straightforward. Using an ISO or the built-in tools, you can set up an environment on Hyper-V, KVM, or other hypervisors. This flexibility means you can keep your development, testing, and production environments consistent across different setups.

Overall, Microsoft’s Azure Linux offers a powerful, flexible way to integrate Linux into your cloud-native workflows. Whether running in the cloud, in a VM, or directly on your PC via WSL, it provides a controlled, secure, and customizable Linux base for modern development.

Inspired by

• https://www.infoworld.com/article/4043164/up-and-running-with-azure-linux-3-0.html

Sources

• gmpg.org
• microsoft.com
• microsoft.com
• microsoft.com
• github.com