When we started working on building images from bootc-containers we created a tool called bootc-image-builder. This is a tool that is shipped as a container to users that can turn bootc-containers into disk images or installers for deployment to virtual machines or bare metal.
Having this in a separate executable allowed us to iterate faster without having to integrate (as much) into the libraries we use in our other tooling such as image-builder, and osbuild-composer. It also allowed us to test having an executable that did not rely on daemons and sockets like we did with osbuild-composer.
As time went on we wanted to apply the no-daemons approach to our other executables as well. Thus image-builder was born and is geared up to eventually replace usage of osbuild-composer. image-builder, like bootc-image-builder is available as a container or can be installed through normal package management on Fedora, CentOS, and RHEL (starting in 9.7 and 10.1). bootc support in image-builder is currently only available on Fedora and CentOS but will be available in RHEL 9.8 and 10.2.
Over the past month or two we’ve largely merged the two different executables into image-builder. This means that image-builder itself now has all the functionality that bootc-image-builder also has. We’ve also made it so that bootc-image-builder can be multi-call binary to image-builder itself.
We still have a bunch of work to do before this merge is complete and you can keep using bootc-image-builder as your entrypoint to building bootc-containers into artifacts. Eventually we’ll switch over to using the multi-call binary by default for bootc-image-builder and then at some point in the further future it is likely that we will only offer image-builder.
This is a good time to take a look at using image-builder directly, we have some documentation describing its command line and functionality. While the arguments are different the functionality stays the same.
For a quick reference let’s go over some common bootc-image-builder commands mapped onto image-builder.
Building a bootc-container into a qcow2.
$ sudo podman pull quay.io/centos-bootc/centos-bootc:stream10
$ mkdir output
$ sudo podman run \
--rm \
-it \
--privileged \
--pull=newer \
--security-opt label=type:unconfined_t \
-v ./config.toml:/config.toml:ro \
-v ./output:/output \
-v /var/lib/containers/storage:/var/lib/containers/storage \
quay.io/centos-bootc/bootc-image-builder:latest \
--type qcow2 \
--use-librepo=True \
quay.io/centos-bootc/centos-bootc:stream10
Would become:
$ sudo podman pull quay.io/centos-bootc/centos-bootc:stream10
$ sudo image-builder build --bootc-ref quay.io/centos-bootc/centos-bootc:stream10 qcow2
Building a bootc-container into an Anaconda installer.
$ sudo podman pull quay.io/centos-bootc/centos-bootc:stream10
$ mkdir output
$ sudo podman run \
--rm \
-it \
--privileged \
--pull=newer \
--security-opt label=type:unconfined_t \
-v ./config.toml:/config.toml:ro \
-v ./output:/output \
-v /var/lib/containers/storage:/var/lib/containers/storage \
quay.io/centos-bootc/bootc-image-builder:latest \
--type anaconda-iso \
--use-librepo=True \
quay.io/centos-bootc/centos-bootc:stream10
Would become:
$ sudo podman pull quay.io/centos-bootc/centos-bootc:stream10
$ sudo image-builder build --bootc-ref quay.io/centos-bootc/centos-bootc:stream10 anaconda-iso
The above examples assume that you’ve done a dnf install image-builder. You can also use the same container-based workflow with image-builder. Here’s an example of using the image-builder upstream container to build a bootc-container into a qcow2 disk image:
$ sudo podman pull quay.io/centos-bootc/centos-bootc:stream10
$ sudo podman run \
--rm \
-it \
--privileged \
--pull=newer \
--security-opt label=type:unconfined_t \
-v ./output:/output \
-v /var/lib/containers/storage:/var/lib/containers/storage \
ghcr.io/osbuild/image-builder-cli:latest \
build \
--output-dir /output \
--bootc-ref quay.io/centos-bootc/centos-bootc:stream10 \
qcow2