nixos/update-users-groups: /etc/shadow owned by root:shadow

nixos/modules/config/update-users-groups.pl

@@ -281,6 +281,12 @@ foreach my $u (values %usersOut) {
 }
 
 updateFile("/etc/shadow", \@shadowNew, 0600);
+{
+    my $uid = getpwnam "root";
+    my $gid = getgrnam "shadow";
+    my $path = "/etc/shadow";
+    chown($uid, $gid, $path) || die "Failed to change ownership of $path: $!";
+}
 
 # Rewrite /etc/subuid & /etc/subgid to include default container mappings
 

nixos/modules/config/users-groups.nix

@@ -537,6 +537,7 @@ in {
       input.gid = ids.gids.input;
       kvm.gid = ids.gids.kvm;
       render.gid = ids.gids.render;
+      shadow.gid = ids.gids.shadow;
     };
 
     system.activationScripts.users = stringAfter [ "stdio" ]

nixos/modules/misc/ids.nix

@@ -346,6 +346,7 @@ in
       paperless = 315;
       #mailman = 316;  # removed 2019-08-30
       zigbee2mqtt = 317;
+      # shadow = 318; # unused
 
       # When adding a uid, make sure it doesn't match an existing gid. And don't use uids above 399!
 
@@ -647,6 +648,7 @@ in
       paperless = 315;
       #mailman = 316;  # removed 2019-08-30
       zigbee2mqtt = 317;
+      shadow = 318;
 
       # When adding a gid, make sure it doesn't match an existing
       # uid. Users and groups with the same name should have equal