From e499f0ee37ffbbd3cdef2e2bbeb7d8d2cfe577a8 Mon Sep 17 00:00:00 2001
From: Ryan Yin <xiaoyin_c@qq.com>
Date: Fri, 9 Jun 2023 10:35:11 +0800
Subject: [PATCH] feat: nix.gc.automatic = true

---
 flake.nix                      |  4 +---
 modules/nixos/core-desktop.nix | 14 ++++++++++++++
 modules/nixos/core-server.nix  | 14 ++++++++++++++
 3 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/flake.nix b/flake.nix
index f5efb4ad..63035d16 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,11 +1,9 @@
 {
   description = "NixOS configuration of Ryan Yin";
 
+  # the nixConfig here only affects the flake itself, not the system configuration!
   nixConfig = {
     experimental-features = [ "nix-command" "flakes" ];
-    # Manual optimise storage: nix-store --optimise
-    # https://nixos.org/manual/nix/stable/command-ref/conf-file.html#conf-auto-optimise-store
-    auto-optimise-store = true;
 
     substituters = [
       # replace official cache with a mirror located in China
diff --git a/modules/nixos/core-desktop.nix b/modules/nixos/core-desktop.nix
index 68075457..ec711f3f 100644
--- a/modules/nixos/core-desktop.nix
+++ b/modules/nixos/core-desktop.nix
@@ -1,6 +1,20 @@
 { config, pkgs, devenv, ... }:
 
 {
+  # for nix server, we do not need to keep too much generations
+  boot.loader.systemd-boot.configurationLimit = 10;
+  # boot.loader.grub.configurationLimit = 10;
+  # do garbage collection weekly to keep disk usage low
+  nix.gc = {
+    automatic = true;
+    dates = "weekly";
+    options = "--delete-older-than 1w";
+  };
+
+  # Manual optimise storage: nix-store --optimise
+  # https://nixos.org/manual/nix/stable/command-ref/conf-file.html#conf-auto-optimise-store
+  auto-optimise-store = true;
+
   # enable flakes globally
   nix.settings.experimental-features = [ "nix-command" "flakes" ];
 
diff --git a/modules/nixos/core-server.nix b/modules/nixos/core-server.nix
index c8aa7834..468c085c 100644
--- a/modules/nixos/core-server.nix
+++ b/modules/nixos/core-server.nix
@@ -1,6 +1,20 @@
 { config, pkgs, devenv, ... }:
 
 {
+  # for nix server, we do not need to keep too much generations
+  boot.loader.systemd-boot.configurationLimit = 10;
+  # boot.loader.grub.configurationLimit = 10;
+  # do garbage collection weekly to keep disk usage low
+  nix.gc = {
+    automatic = true;
+    dates = "weekly";
+    options = "--delete-older-than 1w";
+  };
+
+  # Manual optimise storage: nix-store --optimise
+  # https://nixos.org/manual/nix/stable/command-ref/conf-file.html#conf-auto-optimise-store
+  auto-optimise-store = true;
+
   # enable flakes globally
   nix.settings.experimental-features = [ "nix-command" "flakes" ];