Creating a NixOS live CD
motivation
creating a modified NIXOS live CD out of a working nixos installation gives you the benefits:
- verify what is included
- no need to download it
- it is easy to add your own programs to the image
how to build your own image
Create a file "iso.nix":
# This module defines a small NixOS installation CD. It does not
# contain any graphical stuff.
{config, pkgs, ...}:
{
imports = [
<nixpkgs/nixos/modules/installer/cd-dvd/installation-cd-minimal.nix>
# Provide an initial copy of the NixOS channel so that the user
# doesn't need to run "nix-channel --update" first.
<nixpkgs/nixos/modules/installer/cd-dvd/channel.nix>
];
}
Build the image via:
nix-build '<nixpkgs/nixos>' -A config.system.build.isoImage -I nixos-config=iso.nix
The resulting image can be found in result:
ls result/iso/
nixos-17.09.git.158ec57-x86_64-linux.iso
Start SSH with your SSH key
In your iso.nix:
# enable ssh in the iso boot process
systemd.services.sshd.wantedBy = lib.mkForce [ "multi-user.target" ];
users.users.root.openssh.authorizedKeys.keys [
"ssh-ed25519 AaAeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee username@host"
];
Add static ip addresses
The following snippet is useful, when static ip addresses are required, e.g. for VPS installation
networking = {
usePredictableInterfaceNames = false;
interfaces.eth0.ip4 = [{
address = "64.137.201.46";
prefixLength = 24;
}];
defaultGateway = "64.137.201.1";
nameServers = [ "8.8.8.8" ];
};
ZFS support
The default iso does not contain zfs tools and drivers by default. This can be changed by:
boot.supportedFilesystems = [ "zfs" ];
in iso.nix
software installation inside the 'once' deployed and booted image
in case you have booted from your image you can add software as described here:
references
- See also section "Building your own NixOS CD" of the NixOS manual.