From b65f1f6df7fc330f9e510217fce9bd1be8fcb832 Mon Sep 17 00:00:00 2001
From: Jack O'Sullivan <jackos1998@gmail.com>
Date: Sun, 19 Feb 2023 17:40:05 +0000
Subject: [PATCH] nixos/containers: Ensure containers have cgroupsv2

---
 nixos/modules/containers.nix | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/nixos/modules/containers.nix b/nixos/modules/containers.nix
index 2277c99..4701609 100644
--- a/nixos/modules/containers.nix
+++ b/nixos/modules/containers.nix
@@ -182,8 +182,12 @@ in
             c.containerSystem;
         in
         {
-          # systemd.nspawn units can't set the root directory directly, but /run/machines/${n} is one of the search paths
-          environment.root = "/run/machines/${n}";
+          environment = {
+            # systemd.nspawn units can't set the root directory directly, but /run/machines/${n} is one of the search paths
+            root = "/run/machines/${n}";
+            # Without this, systemd-nspawn will do cgroupsv1
+            SYSTEMD_NSPAWN_UNIFIED_HIERARCHY = "1";
+          };
           restartTriggers = [
             (''${n}.nspawn:${hashString "sha256" (toJSON config.systemd.nspawn."${n}")}'')
           ];