The Debian installer can be automated with a preconfiguration file. The
installer has many options so the preseed.cfg file can get pretty long. The
configuration file must be available at install time.
This project inserts a preseed.cfg file into an ISO image.
The Debian installer can change on release boundaries, so this project is split up into release folders.
To avoid costly delays check the syntax of the preseed file before using it.
This can be done by running the debconf-set-selections command:
debconf-set-selections -c /path/to/preseed.cfg
This will help find line continuation issues and other syntax errors before the installer does with unhelpful messages. Watch out for spaces AFTER the line continuation character backslash (\).
The latest release as of this document is Debian version 11 code named bullseye and the example-preseed.txt is the preconfiguration file to start with for this release.
Debian version 10 code named buster that has an example-preseed.txt to start with for the buster release.
The Debian Installer Netboot Assistant (di-netboot-assistant) software makes it easy to host Debian install images on a system and other systems can use the Pre eXecution Environment (PXE) to boot the Debian installers.
The Pre eXecution Environment (PXE) introduces its own challenges to the automated install. To use PXE, the system needs to have an active network connection to download the installer binary from the PXE server. Some of the network values (interface, domain, and hostname) are set by the DHCP server and the installer will not overwrite these values from the preseed file.
To set these network values, one can provide them as parameters to the installer from the grub boot instruction.
If running a PXE on a VM remember the host firewall must allow PXE port 69 and DHCP traffic to the VM TCP&UDP port 53 UDP port 67.