Autoinstallable Distributions

The autoinstallation process relies on an several files to initiate the installation. These files include the Linux kernel, an initial RAM disk, and other files required to boot the operating system in installation mode.

Uyuni uses the mgradm tool to copy the installation file from the source to the server container.

You can extract the needed files from a DVD image. For information, see Distribution Based on an ISO Image.

Alternatively, you can install the tftpboot-installation package. For information, see Distribution Based on a RPM Package.

You must also have a base channel synchronized on your Uyuni Server for the same operating system version as those files.

When you have the files ready, and the base channel synchronized, you need to declare the distribution. This operation associates the installation files to the base channel. The distribution can be referred to by one or more installation profiles. For information, see Declare an Autoinstallable Distribution.

1. Distribution Based on an ISO Image

This method assumes you have installation media for the operating system you want to install on the clients. This is usually a DVD .iso image that contains the Linux kernel, an initrd file, and other files required to boot the operating system in installation mode.

Procedure: Importing Files from Installation Media

  1. Use mgradm to import installation data from the ISO image:

    # mgradm distribution copy <image_name>.iso <image_name>

  2. Take a note of the distribution path reported by mgradm. You will need it when you declare the distribution to Uyuni.

1.1. Distribution autodetection and registration

mgradm is able to automatically detect distribution name and register it to the server. Provided ISO image needs to contain a .treeinfo file.

Procedure: Import distribution file with autodetection and registration

  1. Use mgradm:

    # mgradm distribution copy --api-user <username> --api-password <password> <image_name>.iso

2. Distribution Based on a RPM Package

This method works on SUSE systems. It is simpler than importing contents from an installation media, because it uses prepackaged files for your installation system.

Procedure: Extracting Files from an Installation Package

  1. On the Uyuni Server, install the package whose name starts with tftpboot-installation. You can determine its exact name with the command zypper se tftpboot-installation

  2. You can install the package to different root to avoid need for restart using following command:

    # mkdir /opt/tftpinstall
# zypper --installroot /opt/tftpinstall install tftpboot-installation-SLE-Micro-5.5-x86_64

  3. Find the installation files with the command ls -d /opt/tftpinstall/usr/share/tftpboot-installation/*.

  4. Copy installation files using mgradm:

    # mgradm distribution copy /opt/tftpinstall/usr/share/tftpboot-installation/SLE-Micro-5.5-x86_64 SLE-Micro-5.5-x86_64

  5. Take a note of the distribution path reported by mgradm tool. You will need it when you declare the distribution to Uyuni.

  6. After mgradm tool finishes, you can remove /opt/tftpinstall directory.

This procedure prepares the installation of the same operating system version as the one that powers your Uyuni Server. If you want to install a different operating system or version on the client, you need to manually get the package tftpboot-installation-* from the distribution it belongs to. In the Package Search input box Uyuni, search the packages whose names start with tftpboot-installation, then look at the package’s details. They show the local path below /var/spacewalk/.

3. Declare an Autoinstallable Distribution

The next step after extracting the autoinstallation files is to declare an autoinstallable distribution.

Procedure: Declaring an Autoinstallable Distribution

  1. In the Uyuni Web UI, navigate to Systems  Autoinstallation  Distributions.

  2. Click Create Distribution, and complete these fields:

    • In the Distribution Label field, enter a name to identify your autoinstallable distribution.

    • In the Tree Path field, enter the path to the installation media saved on your Uyuni Server.

    • Select the matching Base Channel. This must match the installation media.

    • Select the Installer Generation. This must match the installation media.

    • OPTIONAL: Specify kernel options to use when booting this distribution. There are multiple ways to provide kernel options. Only add options here that are generic for the distribution.

  3. Click Create Autoinstallable Distribution.

The installation files that you prepared might not contain the packages you need to install. If they are not included, add useonlinerepo=1 to the Kernel Options field.

The package repositories contain metadata that can be unsigned. If the metadata is unsigned, add insecure=1 to the Kernel Options field, or use your own GPG key as explained in Use Your Own GPG Key.

These kernel options are needed for example when you use the "online installer" ISO images instead of the full DVD, or when you use the tpboot-installation package.

Navigate to Systems  Autoinstallation  Distributions to manage your autoinstallable distributions.

4. Handling Kernel Options for Distributions and Profiles

Uyuni is able to combine the kernel options that you assign. This is done using a special inheritance logic. There are three object types that are relevant for this:

  1. Distributions (or short "Distros")

  2. Profiles

  3. Systems

As a fourth special point of influence on the final kernel options is the Cobbler settings file /etc/cobbler/settings.yaml. The Cobbler settings file defines default kernel options for all distributions. This is not supported in the context of Uyuni.

Understanding raw and resolved values is crucial for managing kernel options effectively.

  1. Raw values: These refer to values attached directly to a specific Cobbler item and stored as-is in Cobbler’s internal database.

  2. Resolved values: These values are dynamically generated at runtime, respecting the inheritance hierarchy of Cobbler items.

If you prefix an option with ! then the option will be removed from the final kernel command line.

Uyuni will manage the kernel options for both Profiles and Systems for you. As such you may only edit the kernel options for Distros.

4.1. Examples

4.1.1. Basic Inheritance Example

Distribution raw value

install=http://uyuni.server/ks/dist/SLES15SP4 self_update=0

Profile raw value

console=tty1

System raw value

console=ttyS0

Resolved value for a system inheriting this profile

install=http://uyuni.server/ks/dist/SLES15SP4 self_update=0 console=ttyS0

4.1.2. Option Removal Example

Distribution raw value

install=http://uyuni.server/ks/dist/SLES15SP4 self_update=0

Profile raw value

console=tty1

System raw value

!self_update

Resolved value for a system inheriting this profile

install=http://uyuni.server/ks/dist/SLES15SP4 console=ttyS0