#!/bin/bash -lx

# Setup arch pxe boot server from the base image.
# Requires manually downloading image to /a/opt, and set it's name below.

set -eE -o pipefail
trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR

cd /a/opt
#iso="archlinux-2015.11.01-dual"
iso="archlinux-2016.01.01-dual"
sfs=$iso/arch/x86_64/airootfs.sfs
rm -rf $iso
ex $iso.iso
sed -i -f - $iso/arch/boot/syslinux/archiso_pxe64.cfg <<EOF
1itotaltimeout 1
/^LABEL arch64_nfs/a menu default
s/^APPEND .*/\0 script=myarchinit.sh/
EOF
# based on https://blog.chendry.org/2015/02/06/automating-arch-linux-installation.html
# and https://wiki.archlinux.org/index.php/Remastering_the_Install_ISO

s rm -rf squashfs-root # remove any existing folder
s unsquashfs $sfs
s mkdir -p squashfs-root/root/.ssh
s chmod 755 squashfs-root/root/.ssh
s cp ~/.ssh/id_rsa.pub squashfs-root/root/.ssh/authorized_keys
s dd of=squashfs-root/root/myarchinit.sh <<EOF
#!/bin/bash
echo $(date) > /tmp/myarchinit.log
dhcpcd eth0
systemctl start sshd
EOF
s rm $sfs
s mksquashfs squashfs-root $sfs -comp xz
# file transfer to wrt is slow, so remove some useless files
rm $iso/arch/i686/airootfs.sfs $iso/arch/boot/i686/archiso.img
c $(dirname $sfs); md5sum ${sfs##*/} > airootfs.md5; b

# seems if you've done a pxe boot, mounted the nfs,
# then shutdown, it's still busy.
ssh wrt "/etc/init.d/nfsd stop; \
{ ! mount | grep /run/archiso/bootmnt || umount /run/archiso/bootmnt; } && \
rm -rf /mnt/usb/$iso"
scp -r $iso wrt:/mnt/usb
ssh wrt "cd /mnt/usb && rm -f tftpboot && ln -s $iso tftpboot"

# The default settings in the installer expect to find the NFS at /run/archiso/bootmnt

pxe-server arch

# background:
# great documentation at https://wiki.archlinux.org/index.php/PXE
# background: arch can do netboot like ubuntu etc, but the docs look a little complicated, so fuck it,
# we use nfs cuz it's easy

rm -rf $iso
s rm -rf squashfs-root