nixos/ids: information when to use static uids/gids

1 files changed, 8 insertions, 0 deletions

diff --git a/nixos/modules/misc/ids.nix b/nixos/modules/misc/ids.nix
index cc7d86849824..bb97c707bf65 100644
--- a/nixos/modules/misc/ids.nix
+++ b/nixos/modules/misc/ids.nix
@@ -1,6 +1,14 @@
 # This module defines the global list of uids and gids.  We keep a
 # central list to prevent id collisions.
 
+# IMPORTANT!
+# We only add static uids and gids for services where it is not feasible
+# to change uids/gids on service start, in example a service with a lot of
+# files. Please also check if the service is applicable for systemd's
+# DynamicUser option and does not need a uid/gid allocation at all.
+# Systemd can also change ownership of service directories using the
+# RuntimeDirectory/StateDirectory options.
+
 { config, pkgs, lib, ... }:
 
 {