homelab/active/software_osbuild/image_builder.md

Image Builder

Builds Fedora/RHEL/Centos images like Packer but for Red Hat.

https://osbuild.org/docs/user-guide/blueprint-reference/

Warning

From the Red Hat Documentation:

You cannot build an operating system image that differs from the RHEL image builder host. For example, you cannot use a RHEL system to build Fedora or CentOS images.

Installing

# Install the packages
dnf install -y osbuild-composer composer-cli

# Start/enable the service
systemctl enable --now osbuild-composer.socket

# Optional: add your user to the weldr group
sudo usermod -aG weldr $USER

# Optional: cockpit dependency
dnf install -y cockpit-composer

Building Images

1. Create a toml file describing your image

   See fedora-42-base.toml for an example.

2. Push the toml to composer

   composer-cli blueprints push active/software_osbuild/fedora-42-base.toml
   
   # List blueprints
   composer-cli blueprints list
   

3. Generate the image

   # List image types
   composer-cli compose types
   
   # Build the image
   composer-cli compose start fedora-42-base qcow2
   
   # Check status
   composer-cli compose status
   

4. Run the image

   # Download the image
   composer-cli compose image --filename ~/Downloads/fedora-42-base.qcow2 image-uuid
   
   # Test with qemu
   qemu-kvm --name test-fedora-42-base -m 4096 -hda ~/Downloads/fedora-42-base.qcow2