nixpkgs/nixos/modules/misc/version.nix
Eelco Dolstra 83eb49220b Manual: Only include the release number (e.g. 16.03)
This prevents gratuitous rebuilds of the manual every time the Git
revision changes.

Should help a bit with #17261.
2016-08-01 11:10:21 +02:00

114 lines
3.5 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.system;
releaseFile = "${toString pkgs.path}/.version";
suffixFile = "${toString pkgs.path}/.version-suffix";
revisionFile = "${toString pkgs.path}/.git-revision";
gitRepo = "${toString pkgs.path}/.git";
gitCommitId = lib.substring 0 7 (commitIdFromGitRepo gitRepo);
in
{
options.system = {
stateVersion = mkOption {
type = types.str;
default = cfg.nixosRelease;
description = ''
Every once in a while, a new NixOS release may change
configuration defaults in a way incompatible with stateful
data. For instance, if the default version of PostgreSQL
changes, the new version will probably be unable to read your
existing databases. To prevent such breakage, you can set the
value of this option to the NixOS release with which you want
to be compatible. The effect is that NixOS will option
defaults corresponding to the specified release (such as using
an older version of PostgreSQL).
'';
};
nixosLabel = mkOption {
type = types.str;
description = ''
Label to be used in the names of generated outputs and boot
labels.
'';
};
nixosVersion = mkOption {
internal = true;
type = types.str;
description = "The full NixOS version (e.g. <literal>16.03.1160.f2d4ee1</literal>).";
};
nixosRelease = mkOption {
readOnly = true;
type = types.str;
default = readFile releaseFile;
description = "The NixOS release (e.g. <literal>16.03</literal>).";
};
nixosVersionSuffix = mkOption {
internal = true;
type = types.str;
default = if pathExists suffixFile then readFile suffixFile else "pre-git";
description = "The NixOS version suffix (e.g. <literal>1160.f2d4ee1</literal>).";
};
nixosRevision = mkOption {
internal = true;
type = types.str;
default = if pathExists revisionFile then readFile revisionFile else "master";
description = "The Git revision from which this NixOS configuration was built.";
};
nixosCodeName = mkOption {
readOnly = true;
type = types.str;
description = "The NixOS release code name (e.g. <literal>Emu</literal>).";
};
defaultChannel = mkOption {
internal = true;
type = types.str;
default = https://nixos.org/channels/nixos-unstable;
description = "Default NixOS channel to which the root user is subscribed.";
};
};
config = {
system = {
# These defaults are set here rather than up there so that
# changing them would not rebuild the manual
nixosLabel = mkDefault cfg.nixosVersion;
nixosVersion = mkDefault (cfg.nixosRelease + cfg.nixosVersionSuffix);
nixosRevision = mkIf (pathIsDirectory gitRepo) (mkDefault gitCommitId);
nixosVersionSuffix = mkIf (pathIsDirectory gitRepo) (mkDefault (".git." + gitCommitId));
# Note: code names must only increase in alphabetical order.
nixosCodeName = "Flounder";
};
# Generate /etc/os-release. See
# http://0pointer.de/public/systemd-man/os-release.html for the
# format.
environment.etc."os-release".text =
''
NAME=NixOS
ID=nixos
VERSION="${config.system.nixosVersion} (${config.system.nixosCodeName})"
VERSION_ID="${config.system.nixosVersion}"
PRETTY_NAME="NixOS ${config.system.nixosVersion} (${config.system.nixosCodeName})"
HOME_URL="http://nixos.org/"
'';
};
}