nixos-option - Man Page

inspect a NixOS configuration

Examples (TL;DR)

List all subkeys of a given option key: nixos-option option_key
List current boot kernel modules: nixos-option boot.kernelModules
List authorized keys for a specific user: nixos-option users.users.username.openssh.authorizedKeys.keyFiles|keys
List all remote builders: nixos-option nix.buildMachines
List all subkeys of a given key on another NixOS configuration: NIXOS_CONFIG=path_to_configuration.nix nixos-option option_key
Show recursively all values of a user: nixos-option -r users.users.user

Synopsis

nixos-option [{-r | --recursive}] [-I path] [option.name]

Description

This command evaluates the configuration specified in /etc/nixos/configuration.nix and returns the properties of the option name given as argument.

When the option name is not an option, the command prints the list of attributes contained in the attribute set.

Options

This command accepts the following options:

-r, --recursive: Print all the values at or below the specified path recursively.
-I path: This option is passed to the underlying nix-instantiate invocation.

Environment

NIXOS_CONFIG: Path to the main NixOS configuration module. Defaults to /etc/nixos/configuration.nix.

Examples

Investigate option values:

$ nixos-option boot.loader
This attribute set contains:
generationsDir
grub
initScript

$ nixos-option boot.loader.grub.enable
Value:
true

Default:
true

Description:
Whether to enable the GNU GRUB boot loader.

Declared by:
  "/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/nixos/modules/system/boot/loader/grub/grub.nix"

Defined by:
  "/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/nixos/modules/system/boot/loader/grub/grub.nix"