# 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](https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/9/html-single/composing_installing_and_managing_rhel_for_edge_images/index):

> 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

```bash
# 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

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

3. Generate the image

    ```bash
    # 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

    ```bash
    # List your images
    composer-cli compose list

    # Download the image
    composer-cli compose image --filename /var/lib/libvirt/images/fedora-42-base.qcow2 image-uuid

    # Test with qemu
    qemu-kvm --name test-fedora-42-base -m 4096 -hda ~/Downloads/fedora-42-base.qcow2
    ```