/PockerISO

Use Hashicorp Packer + Docker to Create Bootable Disk Images

Primary LanguageHCLGNU General Public License v3.0GPL-3.0

PockerISO

Use Hashicorp Packer with Docker to build Bootable Image using Containers.

This repository tries its best to replicate Ivan Velichko's @iximiuz docker-to-linux repo but using a single Packer Template which can be configured for different Distribution flavors.

Result

Distribution Name Platform Working
Debian Bullseye
Debian Bookworm		 linux/amd64 ✔️
Ubuntu 20.04 (Focal Fossa)
Ubuntu 22.04 (Jammy Jellyfish)		 linux/amd64 ✔️
Alpine 3.16 linux/amd64 ✔️

Usage

Requirements:

  • GNU Make (>=4.3)
  • Docker (>=20.10.17)
  • Hashicorp Packer (>=1.8.3)

Initialize Packer

Initially download the Docker plugin for Hashicorp Packer using:

make init

Ubuntu / Debian Images

make ubuntu

will build an ubuntu based bootable image

make debian

will build a debian based bootable image

Alpine Images

make alpine

will build an alpine based bootable image

Clean Up

make clean

removes all generated artifacts

How does it work?

  1. Bring up the respective container, install a compatible kernel and systemd in it (for Debian, Ubuntu) and openrc for Alpine.

  2. Let Packer export the container's filesystem from Step 1 to a tarball. The tarball will be made available in the root directory of this repository as {distribution}.tar e.g. ubuntu.tar, debian.tar, alpine.tar

  3. Unpack the filesystem tarball in a directory namely {distribution}.dir. This is mainly because Packer + Docker will often fail when trying to extract the tarball within the container. It will be easier to just copy the extracted content to the respective mount point in the container

  4. the bash script in scripts directory takes the responsibility for creating a bootable image which will be available in the root directory of the repo as {distribution}.img and {distribution}.qcow2

Emulating Results with QEMU

For amd64 images, the final .img file will be created with root ownership, which will require sudo privileges

sudo qemu-system-x86_64 -m 4096 -smp 4 -drive file={distribution}.img,index=0,media=disk,format=raw

here {distribution} will be either ubuntu, debian, alpine.

Credits / Resources