bootc-examples: An HCL repository from sallyom

Bootable container images with autoupdate systemd service

This repository shows an example to customize a base bootc image with desired features. An autoupdate service and passwordless sudo are added to a base bootc image. Embedded in this repository is also a quadlet (systemd managed podman container) to run a local AI chat application, as well as a quadlet to run a caddy web-server application. Use the examples from this repository to create your own customized bootc-enabled operating system image.

Get started with a bootc-enabled virtual machine

To launch a bootc-enabled virtual machine with KVM/QEMU, see virt-install document

Customize the bootc image

This repository holds the files to build a bootable container image with Colin Walters's autonomous-podman-hello, and also an example systemd service that provides a local LLM and a python script that utilizes the LLM. The service includes podman-autoupdate to enable iteration of the model and script with pushes to a container registry.

Update bootc system to a custom OS image

To build a custom bootc image derived from quay.io/centos-bootc/fedora-bootc:eln, customize the Containerfile as desired, then run

podman build -t quay.io/your-repo/your-os:tag .
podman push quay.io/your-repo/your-os:tag

ssh -i ~/.ssh/your-key fedora@vm-ipaddress

sudo bootc switch quay.io/your-repo/your-os:tag
sudo reboot

Convert from AWS CentOS, RHEL (non-ostree based) system to a `bootc` enabled system.

From a centOS 9 or RHEL 9 ec2 instance: See bootc install docs for more info.

ssh ec2-user@vm-ipaddress
sudo su
podman run --rm --privileged -v /:/target \
             --pid=host --security-opt label=type:unconfined_t \
             quay.io/centos-bootc/centos-bootc-cloud:stream9 \
             bootc install to-filesystem --replace=alongside /target
systemctl reboot

Note: When you ssh in again, the cloud user has changed from ec2-user to cloud-user in AWS instance. The system is now bootc enabled and tracking the given OCI image for updates

Now that the instance is bootc-enabled, follow the above example to update a bootc system with a custom image. However, at this time, you must not mix centos/rhel based systems with fedora based systems. In the future this may not be an issue.

The base images available currently are listed below.

Base bootc images

# for customizing CentOS or RHEL OS image
FROM quay.io/centos-bootc/centos-bootc:stream9

# for customizing cloud images (AMIs) that are CentOS or RHEL based
FROM quay.io/centos-bootc/centos-bootc-cloud:stream9

# for customizing fedora OS image
FROM quay.io/centos-bootc/fedora-bootc:eln

Auto-update with bootable OCI image

With podman-autoupdate the system is updated by pushing a new image to a registry - when it changes, the host will automatically fetch it and reboot with bootc upgrade --apply. To rebase to a fedora-bootc image that has the podman auto-update service enabled:

bootc switch quay.io/sallyom/fedora-bootc:autoupdate

Benefits of bootc

OCI image tools can be utilized to streamline and simplify OS updates. Mostly immutable (read-only) systems discourages infrastructure drift with atomic upgrades.

Instead of delivering OS updates in a traditional way, bootc packages and delivers OS images as OCI objects. All the OCI tools you are familiar with can now be used to manage the operating system. With fleets of systems, this centralized pull-based model simplifies updates.

If you are intrigued, you might also check out:

How do I run the python AI example?

Embedded in the bootable image is /usr/share/containers/systemd/chatapp.container quadlet will create a systemd service, chatapp that includes an LLM, python, and an example script. This service manages a podman container that runs quay.io/sallyom/chatbot:arm.

The chatapp service will be running in a machine booted from quay.io/sallyom/fedora-bootc:autoupdate. Interact with the model by navigating the browser at http://machine-ip:5555.

sallyom/bootc-examples