Microsoft announced the first publicly available experimental build of the distribution Azure Linux 4.0, designed for running in virtual machines and containers. They plan to release experimental builds for WSL (Windows Subsystem for Linux) and AKS (Azure Kubernetes Service) in the future. Azure Linux 4 is positioned as a versatile solution optimized for the Azure platform, suitable for various Azure-related tasks, from virtual machines and containers to nodes in Kubernetes clusters and developer systems. Distribution-specific changes are available under the MIT license.
Compared to Azure Linux 3.0, the new branch has transitioned from its own package base to utilizing packages from the Fedora 43 distribution. Standard SRPM packages from Fedora repositories serve as the foundation, complemented by a set of overlays – configuration files in TOML format facilitating package reconstruction with necessary additions, optimizations, and alterations for Azure Linux. The azldev toolkit, written in Go and distributed under the MIT license, is utilized to generate resulting RPM packages based on Fedora SRPM packages and overlays. The Azure Linux build system supports the creation of traditional installation environments with RPM packages and monolithic atomically updated system images.
Azure Linux 4.0 ships with the Linux 6.18 kernel featuring additional optimizations, enhanced protection against supply chain attacks, a predictable support and update cycle, tools for Azure cloud integration, and security enhancements like system call filtering, disk partition encryption, repository and package verification using digital signatures, protection against symbolic link-related attacks, and buffer overflow protection options. New drivers tailored for Azure equipment, improved Hyper-V hypervisor integration, and GPU and AI accelerator support are included. The package manager tdnf has been replaced by dnf5, with support for SELinux. Key versions of system components include glibc 2.42, OpenSSL 3.5