Iconograph

Iconograph ("icon") is a system for building and deploying Ubuntu system images. It allows you to distribute your software intended to run on real hardware or inside a container as a single unit with its system dependencies, and to roll forward and backward in a secure, repeatable, staged manner.

Images utilize a tmpfs overlay filesystem, so by default filesystem changes are discarded on reboot or upgrade.

Setup

sudo apt-get install --assume-yes git grub-pc xorriso squashfs-tools openssl python3-openssl debootstrap
git clone https://github.com/robot-tools/iconograph.git
cd iconograph

Image creation

Overview

Icon creates images by merging the kernel and boot system of a desktop live CD with a server/custom filesystem. You'll need to download the desktop live CD ISO for the version that you're building. You can get them here.

Serving

Images are fetched via HTTP. You should write images to a directory accessible via HTTP. Install apache2 if need be.

Simple image build

# Must run as sudo to mount/umount images, tmpfs, and overlayfs
sudo server/build_image.py --image-dir=/output/path --release=trusty --source-iso=path/to/ubuntu-14.04.4-desktop-amd64.iso

Modules

Modules are scripts that run after the chroot has been created. They can install packages, do configuration, etc. Icon has several stock modules, but you can also create your own using them as examples. You can pass multiple --module flags to build_image.py as long as the modules are compatible with each other.

Stock modules:

iconograph.py

Install icon inside the image. This allows the image to auto-update over HTTP. Use the build_image.py flag:

--module="server/modules/iconograph.py --base-url=http://yourhost/ --ca-cert=/path/to/signing/cert.pem"

persistent.py

Mount a /persistent partition from a filesystem with LABEL=PERSISTENT. Allows data to persist across reboots, when it would normally be wiped by tmpfs. Use the build_image.py flag:

--module="server/modules/persistent.py"

autoimage.py

Build an image that will partition, mkfs, and install an image from a different URL onto a target system. Used to create install USB drives, PXE boot, etc. Use the build_image.py flag:

--module="server/modules/autoimage.py --base-url=http://yourhost/ --ca-cert=/path/to/signing/cert.pem --device=/dev/sdx --persistent-percent=50"

--device specifies the device to partition and install to on the target system.

--persistent-percent, if non-zero, specifies the percent of the target device to allocate to a LABEL=PERSISTENT filesystem. If the inner image uses persistent.py, this filesystem will be automatically mounted.