/hypersolid

deploy an os like an app - embedded debian builder with merged squasfhs+tmpfs+overlayfs

Primary LanguageShellGNU General Public License v2.0GPL-2.0

hypersolid

build a custom debian image with multistrap into a single squasfs-file with tmpfs overlay

NOTE: this buildsystem is targeted to advanced/professional users with a several years of experience with linux/debian/docker only!

DO NOT USE THIS SYSTEM/IMAGES AS BEGINNER

Features

  • 3 File - full featured - Debian Linux
  • Build a full customized debian image from scratch
  • Multistrap based bootstrapping
  • rootfs wrapped into single squashfs file
  • Immutable filesystem (squashfs base with tmpfs overlay via overlayfs)
  • Persistent storage option (additional overlayfs base)
  • Build environment is isolated within a systemd-nspawn container
  • Minimal system including systemd and networking
  • Multiple build hooks to run custom scripts during build process
  • Hooks for setup/signing/deployment tasks
  • Initramfs creation
  • CLI mode (no GUI)

Devices / Use Cases

Create highly customizable and fully immutable images for:

  • Bare metal servers
  • Cloud servers
  • Workstations
  • Fat-clients / thin-clients
  • IoT devices
  • Firewall/Networkworking equipment
  • Embedded Systems

Target platforms

  • Generic baremetal systems - multiarch
  • Generic virtualized maschines (kvm/quemu) - multiarch

embedded

Build System Requirements

  • Debian Linux based Host System
  • Host System with enabled binfmt-support (for qemu armel emulation)
  • Active Internet connection to fetch the packages or local package server
  • Recommended: apt-cacher-ng within your network or hostsystem
  • sudo to run systemd-nspawn as user
  • ~450MB disk space for the build system
  • ~5GB disk space for the target system

Build System Dependencies

apt-get install sudo systemd-container multistrap binfmt-support qemu-user-static 

sudo for systemd-nspawn

# create group with sudo access to systemd-nspawn
groupadd nspawn

# assign group to your build user
usermod -a -G nspawn myBuildUser

File /etc/sudoers.d/nspawn

%nspawn ALL=(root) NOPASSWD:/usr/bin/systemd-nspawn

Usage

Run hypersolid.sh build <targetdir>

Build

$ ./hypersolid build targets/raspberrypi-zero-w/

How it works

  1. An isolated debian environment it created in /tmp/hypersolid-env via multistrap
  2. The build content (rootfs, scripts, multistrap config) is copied into /tmp/hypersolid-env/build/*
  3. STAGE-1 multistrap is invoked within the build-env to build the base system in <hypersolid-env>/build/target | systemd-nspawn in <hypersolid-env>
  4. STAGE-2 package configuration dpkg --configure is executed within the target environment | systemd-nspawn in <hypersolid-env>/build/target
  5. STAGE-3 squashfs/cpio images are created and kernel+initramfs are copied into <hypersolid-env>/build/dist | systemd-nspawn in <hypersolid-env>

Directories

  • /tmp/hypersolid-env - the isolated build system
  • <hypersolid-env>/build/rootfs - merged rootfs (hypersolid generic + target)
  • <hypersolid-env>/build/target - the multistrap chroot containing the final system
  • <hypersolid-env>/build/dist - output directory including the kernel+initramfs+system image and optional file

License

hypersolid is OpenSource and licensed under the Terms of GNU General Public Licence v2. You're welcome to contribute!