Building with Docker or Podman

This document describes how to build the Kyronix kernel inside a Docker or Podman container. This is the recommended method for reproducible builds.

Overview

The containerized build uses the Containerfile at the repository root, based on Alpine Linux 3.20. The container image includes all required build dependencies: gcc, make, binutils, nasm, bison, flex, cpio, e2fsprogs, xorriso, and others.

Usage

Build any target with the CRUNTIME variable set:

make iso CRUNTIME=podman
make all CRUNTIME=docker

The Makefile automatically builds the container image from Containerfile if it does not exist or if the Containerfile has been modified since the image was last built.
The source tree is mounted at /src inside the container. All build artifacts are written to the host filesystem.

Supported Runtimes

Runtime	Variable	Default
Podman	`CRUNTIME=podman`	Yes (default in Makefile)
Docker	`CRUNTIME=docker`	No

Container Image

The image is tagged kyronix-build:latest by default. Override via CONTAINER_IMAGE and CONTAINER_IMAGE_TAG variables.

make iso CRUNTIME=docker CONTAINER_IMAGE=custom-build CONTAINER_IMAGE_TAG=v1

Cleanup

make clean CRUNTIME=podman

This removes the dist/, build/, and iso_root/ directories on the host, plus rebuilds the container image on the next build.

NOTE: The container image is cached between builds. Only rebuilds when Containerfile changes.

Last reviewed: 2026-07-22