Thank you Philipp, with mirror/https settings everything is now fully going over https.
Here's our working configuration with unauthenticated https installs for 14.04 in case anyone else comes across this:
PXE Config: KERNEL pxelinux.cfg/kernel APPEND append initrd=pxelinux.cfg/initrd.img vga=normal fb=false auto=true priority=critical auto-install/enable=true debian-installer/allow_unauthenticated_ssl=true url=https://buildhost/trusty/preseed.cfg.pl media=https://buildhost/ubuntu/
Preseed Mirror settings: d-i mirror/protocol string https d-i mirror/country string manual d-i mirror/https/hostname string buildhost d-i mirror/https/directory string /ubuntu/ d-i mirror/https/proxy string d-i mirror/https/mirror select mirror
Thank you Philipp, with mirror/https settings everything is now fully going over https.
Here's our working configuration with unauthenticated https installs for 14.04 in case anyone else comes across this:
PXE Config: pxelinux. cfg/initrd. img vga=normal fb=false auto=true priority=critical auto-install/ enable= true debian- installer/ allow_unauthent icated_ ssl=true url=https:/ /buildhost/ trusty/ preseed. cfg.pl media=https:/ /buildhost/ ubuntu/
KERNEL pxelinux.cfg/kernel
APPEND append initrd=
Preseed Mirror settings: https/hostname string buildhost https/directory string /ubuntu/
d-i mirror/protocol string https
d-i mirror/country string manual
d-i mirror/
d-i mirror/
d-i mirror/https/proxy string
d-i mirror/https/mirror select mirror