nixpkgs/modules/profiles/installation-device.nix

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# Provide a basic configuration for installation devices like CDs.
{ config, pkgs, modules, ... }:
with pkgs.lib;
let
# Location of the repository on the harddrive
nixosPath = toString ../..;
# Check if the path is from the NixOS repository
isNixOSFile = path:
let s = toString path; in
removePrefix nixosPath s != s;
# Copy modules given as extra configuration files. Unfortunately, we
# cannot serialized attribute set given in the list of modules (that's why
# you should use files).
moduleFiles =
filter isPath modules;
# Partition module files because between NixOS and non-NixOS files. NixOS
# files may change if the repository is updated.
partitionedModuleFiles =
let p = partition isNixOSFile moduleFiles; in
{ nixos = p.right; others = p.wrong; };
# Path transformed to be valid on the installation device. Thus the
# device configuration could be rebuild.
relocatedModuleFiles =
let
relocateNixOS = path:
"<nixos" + removePrefix nixosPath (toString path) + ">";
relocateOthers = null;
in
{ nixos = map relocateNixOS partitionedModuleFiles.nixos;
others = []; # TODO: copy the modules to the install-device repository.
};
# A dummy /etc/nixos/configuration.nix in the booted CD that
# rebuilds the CD's configuration (and allows the configuration to
# be modified, of course, providing a true live CD). Problem is
# that we don't really know how the CD was built - the Nix
# expression language doesn't allow us to query the expression being
# evaluated. So we'll just hope for the best.
configClone = pkgs.writeText "configuration.nix"
''
{ config, pkgs, ... }:
{
require = [
${toString config.installer.cloneConfigIncludes}
];
}
'';
in
{
imports = [
# Enable devices which are usually scanned, because we don't know the
# target system.
../installer/scan/detected.nix
../installer/scan/not-detected.nix
];
options = {
installer.cloneConfig = mkOption {
default = true;
description = ''
Try to clone the installation-device configuration by re-using it's
profile from the list of imported modules.
'';
};
installer.cloneConfigIncludes = mkOption {
default = [];
example = [ "./nixos/modules/hardware/network/rt73.nix" ];
description = ''
List of modules used to re-build this installation device profile.
'';
};
};
config = {
installer.cloneConfigIncludes =
relocatedModuleFiles.nixos ++ relocatedModuleFiles.others;
# Show the manual.
services.nixosManual.showManual = true;
# Let the user play Rogue on TTY 8 during the installation.
services.rogue.enable = true;
# Disable some other stuff we don't need.
security.sudo.enable = false;
# Include only the en_US locale. This saves 75 MiB or so compared to
# the full glibcLocales package.
i18n.supportedLocales = ["en_US.UTF-8/UTF-8" "en_US/ISO-8859-1"];
boot.postBootCommands =
''
# Provide a mount point for nixos-install.
mkdir -p /mnt
${optionalString config.installer.cloneConfig ''
# Provide a configuration for the CD/DVD itself, to allow users
# to run nixos-rebuild to change the configuration of the
# running system on the CD/DVD.
cp ${configClone} /etc/nixos/configuration.nix
''}
'';
# Some more help text.
services.mingetty.helpLine =
''
Log in as "root" with an empty password. ${
2013-01-22 11:52:13 +00:00
optionalString config.services.xserver.enable
"Type `start display-manager' to\nstart the graphical user interface."}
'';
# Allow sshd to be started manually through "start sshd". It should
# not be started by default on the installation CD because the
# default root password is empty.
services.openssh.enable = true;
jobs.sshd.startOn = pkgs.lib.mkOverride 50 "";
# Enable wpa_supplicant, but don't start it by default.
networking.wireless.enable = true;
jobs.wpa_supplicant.startOn = pkgs.lib.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.shellInit =
''
export GC_INITIAL_HEAP_SIZE=100000
'';
};
}