Files
athenix/hosts/default.nix
UGA Innovation Factory 6ab5f20946 Rename project to 'Athenix'
2025-12-18 12:07:25 -05:00

301 lines
9.9 KiB
Nix

{
inputs,
hosts ? import ../inventory.nix,
...
}:
# ============================================================================
# Host Generator
# ============================================================================
# This file contains the logic to generate NixOS configurations for all hosts
# defined in inventory.nix. It supports both hostname-based and count-based
# configurations with flexible type associations.
#
# Inventory format:
# {
# "my-hostname" = {
# type = "nix-desktop"; # Host type module to use
# system = "x86_64-linux"; # Optional
# # ... any athenix.* options or device-specific config
# };
#
# "lab-prefix" = {
# type = "nix-laptop";
# count = 5; # Generates lab-prefix1, lab-prefix2, ... lab-prefix5
# devices = {
# "machine-1" = { ... }; # Override for lab-prefix1
# };
# };
# }
let
nixpkgs = inputs.nixpkgs;
lib = nixpkgs.lib;
# Helper to create a single NixOS system configuration
mkHost =
{
hostName,
system ? "x86_64-linux",
hostType,
configOverrides ? { },
externalModulePath ? null,
}:
let
# Load users.nix to find external user modules
pkgs = nixpkgs.legacyPackages.${system};
usersData = import ../users.nix { inherit pkgs; };
accounts = usersData.athenix.users or { };
# Build a map of user names to their nixos module paths (if they exist)
# We'll use this to conditionally import modules based on user.enable
userNixosModulePaths = lib.filterAttrs (_: v: v != null) (
lib.mapAttrs (
name: user:
if (user ? external && user.external != null) then
let
externalPath =
if builtins.isAttrs user.external && user.external ? outPath then
user.external.outPath
else
user.external;
nixosModulePath = externalPath + "/nixos.nix";
in
if
(builtins.isPath externalPath || (builtins.isString externalPath && lib.hasPrefix "/" externalPath))
&& builtins.pathExists nixosModulePath
then
nixosModulePath
else
null
else
null
) accounts
);
# Create conditional wrapper modules for each user's nixos.nix
# Each wrapper checks if the user is enabled before applying the module content
userNixosModules = lib.mapAttrsToList (
name: modulePath:
{
config,
lib,
pkgs,
...
}@args:
let
# Import the user's nixos module - it returns a function or attrset
importedModuleFunc = import modulePath { inherit inputs; };
# If it's a function, call it with the module args; otherwise use as-is
importedModule =
if lib.isFunction importedModuleFunc then importedModuleFunc args else importedModuleFunc;
in
{
config = lib.mkIf (config.athenix.users.${name}.enable or false) importedModule;
}
) userNixosModulePaths;
# Load the host type module
typeFile = ./types + "/${hostType}.nix";
typeModule =
if builtins.pathExists typeFile then
import typeFile { inherit inputs; }
else
throw "Host type '${hostType}' not found in hosts/types/";
# External module from fetchGit/fetchurl
externalPathModule =
if externalModulePath != null then import externalModulePath { inherit inputs; } else { };
# Config override module - translate special keys to athenix options
overrideModule =
{ ... }:
let
cleanConfig = lib.removeAttrs configOverrides [
"type"
"count"
"devices"
"overrides"
"defaultCount"
"buildMethods"
];
specialConfig = lib.optionalAttrs (configOverrides ? buildMethods) {
athenix.host.buildMethods = configOverrides.buildMethods;
};
in
{
config = lib.mkMerge [
cleanConfig
specialConfig
];
};
allModules =
userNixosModules
++ [
typeModule
overrideModule
{ networking.hostName = hostName; }
]
++ lib.optional (externalModulePath != null) externalPathModule;
in
{
system = lib.nixosSystem {
inherit system;
specialArgs = { inherit inputs; };
modules = allModules;
};
modules = allModules;
};
# Process inventory entries - top-level keys are always prefixes
processInventory = lib.mapAttrs (
prefix: config:
let
hostType = config.type or prefix;
system = config.system or "x86_64-linux";
devices = config.devices or { };
hasCount = config ? count;
# Helper to generate hostname from prefix and suffix
# Numbers get no dash: "nix-surface1", "nix-surface2"
# Letters get dash: "nix-surface-alpha", "nix-surface-beta"
mkHostName =
prefix: suffix: usePrefix:
if !usePrefix then
suffix
else if lib.match "[0-9]+" suffix != null then
"${prefix}${suffix}" # numeric: no dash
else
"${prefix}-${suffix}"; # non-numeric: add dash
# Extract common overrides and default count
overrides = config.overrides or { };
defaultCount = config.defaultCount or 0;
# If devices is a number, treat it as count
devicesValue = config.devices or { };
actualDevices = if lib.isInt devicesValue then { } else devicesValue;
actualCount = if lib.isInt devicesValue then devicesValue else (config.count or 0);
# Clean base config - remove inventory management keys
baseConfig = lib.removeAttrs config [
"type"
"system"
"count"
"devices"
"overrides"
"defaultCount"
];
# Generate hosts from explicit device definitions
deviceHosts = lib.listToAttrs (
lib.mapAttrsToList (
deviceKey: deviceConfig:
let
# Check if deviceConfig is a path/derivation (from fetchGit, fetchurl, etc.)
# fetchGit/fetchTarball return an attrset with outPath attribute
isExternalModule =
(builtins.isPath deviceConfig)
|| (builtins.isString deviceConfig && lib.hasPrefix "/" deviceConfig)
|| (lib.isDerivation deviceConfig)
|| (builtins.isAttrs deviceConfig && deviceConfig ? outPath);
# Extract the actual path from fetchGit/fetchTarball results
extractedPath =
if builtins.isAttrs deviceConfig && deviceConfig ? outPath then
deviceConfig.outPath
else
deviceConfig;
# If external module, we use base config + overrides as the config
# and pass the module path separately
actualConfig =
if isExternalModule then (lib.recursiveUpdate baseConfig overrides) else deviceConfig;
# Merge: base config -> overrides -> device-specific config (only if not external module)
mergedConfig =
if isExternalModule then
actualConfig
else
lib.recursiveUpdate (lib.recursiveUpdate baseConfig overrides) deviceConfig;
# Check useHostPrefix from the merged config
usePrefix = mergedConfig.athenix.host.useHostPrefix or true;
hostName = mkHostName prefix deviceKey usePrefix;
# If external module, also add a default.nix path for import
externalModulePath =
if isExternalModule then
if builtins.isPath extractedPath then
extractedPath + "/default.nix"
else if lib.isDerivation extractedPath then
extractedPath + "/default.nix"
else
extractedPath + "/default.nix"
else
null;
in
{
name = hostName;
value = mkHost {
inherit
hostName
system
hostType
externalModulePath
;
configOverrides = mergedConfig;
};
}
) actualDevices
);
# Generate numbered hosts from count or defaultCount
# If devices are specified, defaultCount fills in the gaps
countToUse = if actualCount > 0 then actualCount else defaultCount;
# Get which numbered keys are already defined in devices
existingNumbers = lib.filter (k: lib.match "[0-9]+" k != null) (lib.attrNames actualDevices);
countHosts =
if countToUse > 0 then
lib.listToAttrs (
lib.filter (x: x != null) (
map (
i:
let
deviceKey = toString i;
# Skip if this number is already in explicit devices
alreadyDefined = lib.elem deviceKey existingNumbers;
in
if alreadyDefined then
null
else
let
hostName = mkHostName prefix deviceKey true;
mergedConfig = lib.recursiveUpdate baseConfig overrides;
in
{
name = hostName;
value = mkHost {
inherit hostName system hostType;
configOverrides = mergedConfig;
};
}
) (lib.range 1 countToUse)
)
)
else
{ };
in
lib.recursiveUpdate deviceHosts countHosts
) hosts;
# Flatten the nested structure
allHosts = lib.foldl' lib.recursiveUpdate { } (lib.attrValues processInventory);
in
{
nixosConfigurations = lib.mapAttrs (n: v: v.system) allHosts;
modules = lib.mapAttrs (n: v: v.modules) allHosts;
}