NixOS istallation steps

Following notes from:
  * NixOS manual: https://nixos.org/nixos/manual/
  * https://chris-martin.org/2015/installing-nixos


For systems without CD drive, the NixOS live CD can be booted from a USB stick:

$ curl -O https://d3g5gsiof5omrk.cloudfront.net/nixos/17.03/nixos-17.03.1769.da2159dafb/nixos-minimal-17.03.1769.da2159dafb-x86_64-linux.iso
# dd if=nixos-minimal-17.03.1769.da2159dafb-x86_64-linux.iso of=/dev/sdc

1. Boot from USB drive.
2. When it’s finished booting, it should have detected most of your hardware.
3. The NixOS manual is available on virtual console 8 (press Alt+F8 to access).
4. You get logged in as root (with empty password).
5. The boot process should have brought up networking (check ip a). Networking is necessary for the installer, 
since it will download lots of stuff.
6. Partitioning disk using gdisk to create the following schema:

  1  500MB    EF00 EFI System
  2  465.4GN  8E00 Linux LVM
  
  We'll use the following partition schema:
  
  * /dev/sda1 will be mounted at /boot. This is unencrypted, because the boot process will need it 
  before we unlock the encrypted volume.
  * /dev/sda2 is the encrypted partition.
  
  The encrypted partition /dev/sda2 contains an LVM volume group called vg, which contains two logical volumes:

  * /dev/vg/swap will be used as swap space.
  * /dev/vg/root will be mounted at the root of the filesystem, /.
  
7. Set up LUKS

Initialize the encrypted partition. This will prompt you to create a passphrase.

  # cryptsetup luksFormat /dev/sda2

Then open it:

  # cryptsetup luksOpen /dev/sda2 enc-pv
  
8. Configure LVM:

  pvcreate /dev/mapper/enc-pv
  vgcreate vg /dev/mapper/enc-pv
  
  lvcreate -L 32G -n swap vg
  lvcreate -l100%FREE -n root vg
 
9. Format partitions:
  
  # mkfs.vfat -n BOOT /dev/sda1
  # mkfs.ext4 -L root /dev/vg/root
  # mkswap -L swap /dev/vg/swap

10. NixOS Installation:

The NixOS installer treats /mnt as the filesystem root for the installation. So instead of 
mounting to / and /boot as we discussed above, for now we’re going to mount them to /mnt 
and /mnt/boot instead:

  # mount /dev/vg/root /mnt
  # mkdir /mnt/boot
  # mount /dev/sda1 /mnt/boot
  
Also activate the swap space:

  # swapon /dev/vg/swap
  
  10.1. Configuration:
  
  Run this to generate config files:

  # nixos-generate-config --root /mnt
  
  This creates two files in /mnt/etc/nixos:

  * configuration.nix, a default config file. (You’ll be making changes to this a lot).
  * hardware-configuration.nix, the results of a hardware scan. (You don’t edit this.)
  
  Add this stuff to the configuration.nix:
  
    boot.initrd.luks.devices = [
      {
        name = "root";
        device = "/dev/sda2";
        preLVM = true;
      }
    ];

    boot.loader.grub.device = "/dev/sda";

  Recap of everything you need to set up when you boot from the install media again.

cryptsetup luksOpen /dev/sda2 enc-pv
lvchange -a y /dev/vg/swap
lvchange -a y /dev/vg/root
mount /dev/vg/root /mnt
mount /dev/sda2 /mnt/boot
swapon /dev/vg/swap
  
  10.2. Install:
  
  # nixos-install

If that succeeds, then reboot and proceed to boot into your new NixOS install.

  #reboot