Installing NixOS in a VirtualBox guest

This pages describes how to install NixOS in a VirtualBox guest.

• Download a NixOS ISO from http://nixos.org
• Add a New Machine in VirtualBox with OS Type "Linux / Other Linux"
• Base Memory Size: 768 MB
• New Hard Disk of 8 GB
• Mount the CD-ROM with the NixOS ISO (by clicking on CD/DVD-ROM)
• Click on Settings / Advanced (or possibly System / Processor) and enable PAE/NX
• Networking: select "Attached to: NAT". Change host-interface to "en1: Airport".
• Now you can install NixOS:

 $ fdisk /dev/sda (create a full partition, don't skip this step, example commands for quick setup: n,p,1,w)
 $ mkfs.ext4 -j -L nixos /dev/sda1 (idem)
 $ mount LABEL=nixos /mnt
 $ mkdir -p /mnt/etc/nixos
 $ nixos-hardware-scan > /mnt/etc/nixos/configuration.nix (for quick setup overwrite configuration.nix completely with example below)
 $ nano /mnt/etc/nixos/configuration.nix

(add the fileSystems. this is what my final config looks like:)

 { config, pkgs, ...} :
 {
   boot.loader.grub.device = "/dev/sda";

   services.openssh.enable = true;
   services.virtualbox.enable = true;
   
   fileSystems = [
     { mountPoint = "/";
       label = "nixos";
     }
   ];
 }

Now we're ready to install!

 $ nixos-install
 $ reboot

Now you got a working nixos system.

SSH-ing into the box

However, you can't conveniently log in to ssh this way, so you'll need to set up port-forwarding. Doing that is explained on this site, all you have to do is create a script named "vbox-tunnel" that contains the following lines:

 #!/bin/bash
 cd /Applications/VirtualBox.app/Contents/MacOS/
 ./VBoxManage setextradata "$1" "VBoxInternal/Devices/pcnet/0/LUN#0/Config/$2/Protocol" TCP
 ./VBoxManage setextradata "$1" "VBoxInternal/Devices/pcnet/0/LUN#0/Config/$2/GuestPort" $3
 ./VBoxManage setextradata "$1" "VBoxInternal/Devices/pcnet/0/LUN#0/Config/$2/HostPort" $4

Now execute the script:

 vbox-tunnel Nix sshtunnel 22 2222

You should be able to log in to Nix now by running ssh -p2222 localhost in your OS X Terminal. Enjoy!

Alternative (independent of virtual network card chosen for the guest):

 VBoxManage modifyvm "Nix" --natpf1 "sshtunnel,tcp,,2222,,22"

As before, you are now able to log in to Nix by running ssh -p2222 localhost in your terminal.