I'm sure I'm missing something easy, but I can't think of what it is.
I used Cobbler to import Debian 8.3.0, but when I attempt to install it on a machine attached to the network, the installer asks for a CDROM, fails to find it, and quits.
Does anyone know what I need to tweak in the preseed file or the kernel parameters to tell it to find its install files on a network path?
You need to provide your kernel with the installer in TFTP for the netboot initrd image and point it to the preseed file.
In my TFTP I have got in my default menu
debian-installer/amd64/boot-screens/adtxt.cfg
:Be sure to change it for your keyboard locale, language, your root default filesystem, and the IP/URL of your web server providing your preseed file.
I will leave here a link for the Official Debian guide.
PXEBootInstall
As for the preseed file: