Azure Linux

An open-source Linux distribution built and optimized for Azure, with sources derived from Fedora Linux. Azure Linux provides a secured, reliable operating system for virtual machines, containers, and bare-metal platforms. Azure Linux is built on a robust open-source foundation from the Fedora ecosystem and enhanced with Azure-specific innovations. This provides the familiarity of the RPM package ecosystem, while adding Azure-native security, compliance, and operational capabilities. Key features of Azure Linux include: hardened security posture, an Azure-optimized kernel, supply chain security, native Azure integration, and a predictable lifecycle. This branch holds the in-development sources for Azure Linux 4. For Azure Linux 3, see the 3.0 branch. Product documentation Release information GitHub Releases File a bug / feedback GitHub Issues Ask a question / get help SUPPORT.md Get started as a distro developer DEVELOPING.md Contribution guidelines CONTRIBUTING.md Report a security issue SECURITY.md To try Azure Linux base container, please use the following image reference: mcr.microsoft.com/azurelinux-beta/base/core:4.0 Before using a downloaded ISO, verify the checksum and signature of the ISO. After downloading and verifying the ISO, follow the ISO installer instructions to install and use Azure Linux in a local VM (Hyper-V on Windows or QEMU/KVM on Linux). The ISO runs the Anaconda installer. Deviations from upstream are declaratively defined and scoped to avoid unnecessary divergence or forking. This repository contains a mechanically rendered set of RPM package spec files derived from applying this layer to Fedora's upstream packaging sources. The distro is described almost entirely in TOML-based configuration files. Our open-source development tool, azldev , is used to apply this configuration to upstream Fedora spec files and packaging sources. Concepts/terms Components (also known as source packages) are the unit of packaging. Most are imported in source form from Fedora's upstream dist-git repositories; each component produces one or more RPMs. Azure Linux builds all components from sources to produce a full set of installable RPM packages. Overlays are declarative modifications to upstream specs and sources (e.g., patches, additions/removals, build parameters). They live alongside the component definition and always carry a description explaining why the change is needed. Overlays let us avoid forking upstream specs and are more flexible than plain textual patches. Rendered specs are the final .spec files produced by applying overlays to upstream sources. They are mechanically generated by azldev , checked in for visibility and auditability, and live under specs/ . Treat them as derived output and not sources for editing. We use them as the input to standard RPM building services/tools ( mock + rpmbuild , koji ). For a deeper tour of the tooling, the overlay system, and how to get started developing within this distro, please see DEVELOPING.md. azldev.toml Top-level config — includes distro/ and base/ . distro/ Distro definitions (Azure Linux + upstream Fedora), shared mock configs. base/ The base project: components, images, tests. base/comps/ Component definitions — the heart of the distro. base/images/ Image definitions (VM, container, etc.) built from the component set using KIWI NG . specs/ Rendered specs — generated .spec files after overlays are applied. Checked in for visibility; do not hand-edit. locks/ Per-component lock files pinning upstream commits + input fingerprints; do not hand-edit. external/schemas/ Cached copy of the JSON Schema for TOML config files; mirrored from azldev . .github/ CI workflows, plus Copilot prompts, skills, and agent instructions used by AI-assisted development. If you want to build or develop within the distro, start with DEVELOPING.md . Don't worry about this if you're primarily looking to use the distro. [community-call-join]: This project has adopted the Mic