# build installer

{
  description = "Bcachefs enabled installation media";
  inputs.nixos.url = "nixpkgs/nixos-unstable";
  outputs = { self, nixos }: {
    nixosConfigurations = {
      exampleIso = nixos.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          "${nixos}/nixos/modules/installer/cd-dvd/installation-cd-minimal-new-kernel-no-zfs.nix"
          ({ lib, pkgs, ... }: {
            boot.supportedFilesystems = [ "bcachefs" ];
            boot.kernelPackages = lib.mkOverride 0 pkgs.linuxPackages_latest;
          })
        ];
      };
    };
  };
}

git init
git add flake.nix
nix build .#nixosConfigurations.exampleIso.config.system.build.isoImage

sudo dd if=result/iso/nixos-24.05.20240108.317484b-x86_64-linux.iso of=/dev/sda bs=4M conv=fsync

#
# kill old efi boot stuff
#

efibootmgr
efibootmgr -b 0 -B
efibootmgr -b 1 -B
efibootmgr -b 2 -B
efibootmgr -b 3 -B
efibootmgr -b 4 -B
efibootmgr

#
# install script below
#

# fix unlocking https://nixos.wiki/wiki/Bcachefs
nix-env -iA nixos.keyutils
keyctl link @u @s

# Defining some helper variables (these will be used in later code
# blocks as well, so make sure to use the same terminal session or
# redefine them later)
DISK=/dev/disk/by-id/nvme-CT4000P3PSSD8_2325E6E63746
HOST=mini

# ensure 4k sector size
nvme format --lbaf=1 --force $DISK
nvme id-ns -H $DISK

sleep 5

# kill old data
sgdisk --zap-all $DISK
blkdiscard -v $DISK
wipefs -a $DISK
gdisk -l $DISK

# create partitions
parted $DISK -- mklabel gpt
sgdisk -n 1:0:+1024M -c 1:"EFI System Partition" -t 1:EF00 $DISK
sgdisk -n 2:0:+256G -c 2:"nix" -t 2:8e00 $DISK
sgdisk -n 3:0:0 -c 3:"data" -t 3:8e00 $DISK
parted $DISK -- set 1 boot on

sleep 5

# take a look
cat /proc/partitions

# boot partition
mkfs.fat -F 32 -n EFIBOOT $DISK-part1

# create encrypted bcachefs
bcachefs format --block_size=4096 --errors=ro --metadata_checksum=xxhash --data_checksum=xxhash --compression=lz4 --wide_macs --acl --encrypted --fs_label=nix --discard -f $DISK-part2
bcachefs format --block_size=4096 --errors=ro --metadata_checksum=xxhash --data_checksum=xxhash --compression=lz4 --wide_macs --acl --encrypted --fs_label=data --discard -f $DISK-part3

# prepare install
mount -t tmpfs none /mnt

# Create directories to mount file systems on
mkdir -p /mnt/{data,nix,home,boot,root,etc/nixos}

# mount the ESP
mount $DISK-part1 /mnt/boot

# mount bcachefs stuff
mount -o noatime,nodiratime $DISK-part2 /mnt/nix
mount -o noatime,nodiratime $DISK-part3 /mnt/data

# bind mount persistent stuff to data
mkdir -p /mnt/{data/home,data/root,data/nixos/$HOST}
mount --bind /mnt/data/home /mnt/home
mount --bind /mnt/data/root /mnt/root
mount --bind /mnt/data/nixos/$HOST /mnt/etc/nixos

# take a look
mount

# configure
nixos-generate-config --root /mnt

# save /mnt/etc/nixos/hardware-configuration.nix /mnt/etc/nixos/configuration.nix

cp /mnt/etc/nixos/hardware-configuration.nix /tmp
cp /mnt/etc/nixos/configuration.nix /tmp

# copy config data

# patch some paths there

sudo scp -r /data/nixos root@192.168.13.100:/mnt/data

# install

nixos-install --no-root-passwd --root /mnt

# unmount all stuff

umount -Rl /mnt

#
# after install tasks for extra file systems
#

# create vms disk

DD=/dev/disk/by-id/ata-CT2000MX500SSD1_2138E5D5061F
sgdisk --zap-all $DD
blkdiscard -v $DD
wipefs -a $DD

sleep 5

# create encrypted bcachefs
bcachefs format --block_size=4096 --errors=ro --metadata_checksum=xxhash --data_checksum=xxhash --compression=lz4 --wide_macs --acl --encrypted --fs_label=vms --discard -f $DD