The preseeding feature allows to set answer to questions asked during the i-MSCP installation process, without having to manually enter the answers while the installation is running. This allow to achieve unattended installations, mostly for ISPs that want built server images with i-MSCP pre-installed.
The preseed file is a simple perl script filled with all needed answers. You can either pre-fill it with your own static values or use your own script to generate it according your own dynamic values.
Once the preseed file is created, you must tell the installer to use it. This is achieved by simply running the installer with the preseed command line option such as:
# perl <installer> -dnp <path_to_your_preseed_file>
Here, <installer> refers either to imscp-autoinstall and imscp-setup scripts.
When creating a preseed file, you should start from a known good, default preseed file. A preseed file for the i-MSCP version you are using is located in the docs directory of the archive.