nixpkgs/nixos/modules/virtualisation/lxc-image-metadata.nix

105 lines
3.5 KiB
Nix

{ lib, config, pkgs, ... }:
let
templateSubmodule = {...}: {
options = {
enable = lib.mkEnableOption "this template";
target = lib.mkOption {
description = "Path in the container";
type = lib.types.path;
};
template = lib.mkOption {
description = ".tpl file for rendering the target";
type = lib.types.path;
};
when = lib.mkOption {
description = "Events which trigger a rewrite (create, copy)";
type = lib.types.listOf (lib.types.str);
};
properties = lib.mkOption {
description = "Additional properties";
type = lib.types.attrs;
default = {};
};
};
};
toYAML = name: data: pkgs.writeText name (lib.generators.toYAML {} data);
cfg = config.virtualisation.lxc;
templates = if cfg.templates != {} then let
list = lib.mapAttrsToList (name: value: { inherit name; } // value)
(lib.filterAttrs (name: value: value.enable) cfg.templates);
in
{
files = map (tpl: {
source = tpl.template;
target = "/templates/${tpl.name}.tpl";
}) list;
properties = lib.listToAttrs (map (tpl: lib.nameValuePair tpl.target {
when = tpl.when;
template = "${tpl.name}.tpl";
properties = tpl.properties;
}) list);
}
else { files = []; properties = {}; };
in {
options = {
virtualisation.lxc = {
templates = lib.mkOption {
description = "Templates for LXD";
type = lib.types.attrsOf (lib.types.submodule templateSubmodule);
default = {};
example = lib.literalExpression ''
{
# create /etc/hostname on container creation
"hostname" = {
enable = true;
target = "/etc/hostname";
template = builtins.writeFile "hostname.tpl" "{{ container.name }}";
when = [ "create" ];
};
# create /etc/nixos/hostname.nix with a configuration for keeping the hostname applied
"hostname-nix" = {
enable = true;
target = "/etc/nixos/hostname.nix";
template = builtins.writeFile "hostname-nix.tpl" "{ ... }: { networking.hostName = "{{ container.name }}"; }";
# copy keeps the file updated when the container is changed
when = [ "create" "copy" ];
};
# copy allow the user to specify a custom configuration.nix
"configuration-nix" = {
enable = true;
target = "/etc/nixos/configuration.nix";
template = builtins.writeFile "configuration-nix" "{{ config_get(\"user.user-data\", properties.default) }}";
when = [ "create" ];
};
};
'';
};
};
};
config = {
system.build.metadata = pkgs.callPackage ../../lib/make-system-tarball.nix {
contents = [
{
source = toYAML "metadata.yaml" {
architecture = builtins.elemAt (builtins.match "^([a-z0-9_]+).+" (toString pkgs.system)) 0;
creation_date = 1;
properties = {
description = "${config.system.nixos.distroName} ${config.system.nixos.codeName} ${config.system.nixos.label} ${pkgs.system}";
os = "${config.system.nixos.distroId}";
release = "${config.system.nixos.codeName}";
};
templates = templates.properties;
};
target = "/metadata.yaml";
}
] ++ templates.files;
};
};
}