Azure Linux is for everyone… Azure Linux

After using Azure Linux internally for two years and running in public preview since October 2022, this week Microsoft finally made its distribution available to everyone.

Azure Linux is an open source container host operating system for Azure Kubernetes Service (AKS from Azure Kubernetes Service) that is optimized for Azure and aims to make it easier for developers to use Microsoft tools to deploy and manage containers.

Azure Linux is designed to be deployed in the cloud and run multiple containers together.

The Azure Linux distribution comes from Microsoft’s CBL-Mariner project, where CBL stands for Common Base Linux. Microsoft launched CBL-Mariner because it needed an internal Linux distribution and stable platform for the thousands of workloads its engineers were running on Azure, according to Jim Perrin, program manager for Microsoft Azure Linux.

Microsoft’s custom open source distribution allows us “to have a very specific, very thoughtful focus on Azure and adjust the elements of the distribution to be exactly what we need to support the container host and try to keep the dependencies and external packages in place,” Perrin said during a question-and-answer session at Build 2023, where Redmond announced the launch. General availability of Azure Linux.

This means that Azure Linux’s primary role is as a container host for AKS. It is optimized for Microsoft Windows Hyper-V hypervisor and runs in a virtual machine (VM), supporting both x86 and Arm.

The light nature of the distribution is a key point, Perrin said. The small footprint includes a 400MB kernel image and 300 packages, which Microsoft said does very well for both performance and security.

Perrin said safety was the focus in the postnoting that all OS updates are run through Azure validation tests and that the test suite is constantly updated.

Moreover, because there are much fewer packages on the container host, the volume of security updates required is smaller, and these issues are also fixed promptly. We closely monitor and manage the entire software supply chain, allowing for greater quality assurance and flexibility than beginning to end.”

Also at Build, Microsoft announced that Kubernetes Apps, a suite of open-source third-party applications for the AKS platform, is available on the Azure Marketplace.

Kubernetes applications, in public preview in October 2022, enable one-click deployment, CI/CD automation, automated lifecycle management, and backup.

Available applications are tested and certified by Microsoft and scanned for vulnerabilities, which is a necessary step at a time when the number of attacks across the supply chain continues to increase.