Microsoft recently announced the general availability of Azure Linux container host for AKS. Available on GitHub under the CBL-Mariner project codename, the lightweight Linux distribution includes only the packages needed to run workloads on a cloud environment.
The Azure Linux container host for AKS is an open-source Linux distribution available as a container host on Azure Kubernetes Service (AKS). The new distribution is designed to provide reliability and consistency across the AKS, AKS-HCI, and Arc products. Azure Linux node pools can be deployed in a new cluster or added to existing Ubuntu clusters. It is also possible to migrate existing Ubuntu nodes to Azure Linux nodes.
The distribution is designed to be lightweight, both for performance and security, with a 400MB core image and around 300 packages. Jim Perrin, principal program manager lead at Microsoft, writes:
Azure Linux is designed with a minimalist view and a cloud focus. Window managers and other graphical interfaces are removed, resulting in a lower attack surface, reduced dependencies, and a generally smaller footprint. This ultimately helps reduce update interruptions and improves reboot speeds.
The general availability follows last year's preview announcement and Azure Linux is the same distribution as CBL-Mariner. The distribution has the primary purpose of serving as the container host for AKS (AKS), running as a VM on Hyper-V but bare metal installations on x64 or ARM64 are also possible. Perrin adds:
Getting started with the Azure Linux container host is as easy as changing the OSSku parameter in your ARM template or other deployment tooling.
User cpressland on Reddit writes:
We’ve been running Mariner Linux in Production for just over a month and it’s been absolutely rock solid. Nice to see this get an official name (...) and for our non-AKS workloads I hope this becomes an option there too.
While the general availability is recent, Microsoft claims to be running Mariner as the internal Linux OS since last year, with products such as Xbox, Playfab, Minecraft, and many Azure services deployed on Mariner.
The famous Linux is a cancer quote from Steve Ballmer has been mentioned by many since the announcement. Peter Zaitsev, founder at Percona and open source advocate, tweets:
A couple of decades ago you could hardly imagine there would be such a thing as Microsoft Linux.
Microsoft is not the only cloud provider developing a lightweight distribution for cloud deployments, with Amazon Linux 2023, an option with long-term support on AWS, and Container-Optimized OS from Google, based on the Chromium OS project, other popular choices.
The CBL-Mariner documentation is available on GitHub.