Azure Linux Explained

Azure Linux
Logo Size:	128px
Developer:	Microsoft
Family:	Linux
Source Model:	Open source
Released:	(as CBL-Mariner)
Latest Release Version:	2.0.20240609
Latest Release Date:	^[1]
Marketing Target:	Cloud infrastructure and edge products and services
Programmed In:	Go, Shell script, C, Roff, Python
Kernel Type:	Monolithic (Linux kernel)
License:	Primarily MIT License, with some components under Photon License, Apache License v2, GPLv2, and LGPLv2.1^[2]

Azure Linux, previously known as CBL-Mariner (in which CBL stands for Common Base Linux),^[3] is a free and open-source Linux distribution that Microsoft has developed. It is the base container OS for Microsoft Azure services^{[4] [5]} and the graphical component of WSL 2.^[6]

Overview

CBL-Mariner is being developed by the Linux Systems Group at Microsoft for its edge network services and as part of its cloud infrastructure. The company uses it as the base Linux for containers in the Azure Stack HCI implementation of Azure Kubernetes Service. Microsoft also uses CBL-Mariner in Azure IoT Edge to run Linux workloads on Windows IoT, and as a backend distro to host the Weston compositor for WSLg.^[7]

In a similar approach to Fedora CoreOS, CBL-Mariner only has the basic packages needed to support and run containers. Common Linux tools are used to add packages and manage security updates. Updates are offered either as RPM packages or as complete disk images that can be deployed as needed. Using RPM allows adding custom packages to a base CBL-Mariner image to support additional features and services as needed. Notable features include an iptables-based firewall, support for signed updates, and a hardened kernel.

Microsoft released the operating system in 2020. Its source code is available on GitHub, mainly under the MIT License, with some components under, Apache License v2, GPLv2, and LGPLv2.1. Building CBL-Mariner requires the Go programming language, QEMU utilities, and RPM.

Starting from the release 2.0.20240301, CBL-Mariner is called Azure Linux.^[8]

See also

• SONiC (operating system)
• Windows Subsystem for Linux
• Azure Sphere

Further reading

• Azure Kubernetes Service on Azure Stack HCI: deliver Storage Spaces Direct to containers
• Enabling Linux based Azure IoT Edge Modules on Windows IoT

Notes and References

1. Web site: Release 2.0.20240609 · microsoft/azurelinux . .
2. Web site: CBL-Mariner. GitHub. 21 December 2021.
3. Web site: Mary. Branscombe. What is Microsoft doing with Linux? Everything you need to know about its plans for open source. December 2, 2020. TechRepublic.
4. Web site: Foley. Mary Jo. November 11, 2020. CBL-Mariner: Microsoft's internal Linux distribution for Azure first-party services and edge appliances. ZDNet.
5. Web site: Simon. Bisson. Microsoft adds a new Linux: CBL-Mariner. November 10, 2020. InfoWorld.
6. News: Foley. Mary Jo. 2021-04-21. New Windows 10 test build adds first preview of Linux GUI apps on WSL. 2021-04-23. ZDNet. en-US.
7. Web site: WSLg Architecture . Pronovost . Steve . April 19, 2021 . Windows Command Line . Microsoft . August 14, 2021.
8. Web site: Microsoft Rebranding CBL-Mariner Linux Distribution To "Azure Linux" . . 2024-03-05 . Phoronix Media . 2024-03-06 .