nixpkgs/nixos/modules/profiles/installation-device.nix
2022-04-17 18:31:35 -04:00

122 lines
4.1 KiB
Nix

# Provide a basic configuration for installation devices like CDs.
{ config, pkgs, lib, ... }:
with lib;
{
imports =
[ # Enable devices which are usually scanned, because we don't know the
# target system.
../installer/scan/detected.nix
../installer/scan/not-detected.nix
# Allow "nixos-rebuild" to work properly by providing
# /etc/nixos/configuration.nix.
./clone-config.nix
# Include a copy of Nixpkgs so that nixos-install works out of
# the box.
../installer/cd-dvd/channel.nix
];
config = {
# Enable in installer, even if the minimal profile disables it.
documentation.enable = mkForce true;
# Show the manual.
documentation.nixos.enable = mkForce true;
# Use less privileged nixos user
users.users.nixos = {
isNormalUser = true;
extraGroups = [ "wheel" "networkmanager" "video" ];
# Allow the graphical user to login without password
initialHashedPassword = "";
};
# Allow the user to log in as root without a password.
users.users.root.initialHashedPassword = "";
# Allow passwordless sudo from nixos user
security.sudo = {
enable = mkDefault true;
wheelNeedsPassword = mkForce false;
};
# Automatically log in at the virtual consoles.
services.getty.autologinUser = "nixos";
# Some more help text.
services.getty.helpLine = ''
The "nixos" and "root" accounts have empty passwords.
An ssh daemon is running. You then must set a password
for either "root" or "nixos" with `passwd` or add an ssh key
to /home/nixos/.ssh/authorized_keys be able to login.
If you need a wireless connection, type
`sudo systemctl start wpa_supplicant` and configure a
network using `wpa_cli`. See the NixOS manual for details.
'' + optionalString config.services.xserver.enable ''
Type `sudo systemctl start display-manager' to
start the graphical user interface.
'';
# We run sshd by default. Login via root is only possible after adding a
# password via "passwd" or by adding a ssh key to /home/nixos/.ssh/authorized_keys.
# The latter one is particular useful if keys are manually added to
# installation device for head-less systems i.e. arm boards by manually
# mounting the storage in a different system.
services.openssh = {
enable = true;
permitRootLogin = "yes";
};
# Enable wpa_supplicant, but don't start it by default.
networking.wireless.enable = mkDefault true;
networking.wireless.userControlled.enable = true;
systemd.services.wpa_supplicant.wantedBy = mkOverride 50 [];
# Tell the Nix evaluator to garbage collect more aggressively.
# This is desirable in memory-constrained environments that don't
# (yet) have swap set up.
environment.variables.GC_INITIAL_HEAP_SIZE = "1M";
# Make the installer more likely to succeed in low memory
# environments. The kernel's overcommit heustistics bite us
# fairly often, preventing processes such as nix-worker or
# download-using-manifests.pl from forking even if there is
# plenty of free memory.
boot.kernel.sysctl."vm.overcommit_memory" = "1";
# To speed up installation a little bit, include the complete
# stdenv in the Nix store on the CD.
system.extraDependencies = with pkgs;
[
stdenv
stdenvNoCC # for runCommand
busybox
jq # for closureInfo
# For boot.initrd.systemd
makeInitrdNGTool
systemdStage1
systemdStage1Network
];
# Show all debug messages from the kernel but don't log refused packets
# because we have the firewall enabled. This makes installs from the
# console less cumbersome if the machine has a public IP.
networking.firewall.logRefusedConnections = mkDefault false;
# Prevent installation media from evacuating persistent storage, as their
# var directory is not persistent and it would thus result in deletion of
# those entries.
environment.etc."systemd/pstore.conf".text = ''
[PStore]
Unlink=no
'';
};
}