From 8de3d2b149dff53de62aa8bca40d4b99718abb53 Mon Sep 17 00:00:00 2001
From: Rodrigo Arias Mallo <rodrigo.arias@bsc.es>
Date: Wed, 20 Sep 2023 18:26:48 +0200
Subject: [PATCH] Mount the hut nix store for SLURM jobs

---
 m/module/slurm-hut-nix-store.nix | 19 +++++++++++++++++++
 m/owl1/configuration.nix         |  1 +
 m/owl2/configuration.nix         |  1 +
 3 files changed, 21 insertions(+)
 create mode 100644 m/module/slurm-hut-nix-store.nix

diff --git a/m/module/slurm-hut-nix-store.nix b/m/module/slurm-hut-nix-store.nix
new file mode 100644
index 0000000..2ec8e2f
--- /dev/null
+++ b/m/module/slurm-hut-nix-store.nix
@@ -0,0 +1,19 @@
+{ ... }:
+
+{
+  # Mount the hut nix store via NFS
+  fileSystems."/mnt/hut-nix-store" = {
+    device = "hut:/nix/store";
+    fsType = "nfs";
+    options = [ "ro" ];
+  };
+
+  systemd.services.slurmd.serviceConfig = {
+    # When running a job, bind the hut store in /nix/store so the paths are
+    # available too.
+    # FIXME: This doesn't keep the programs in /run/current-system/sw/bin
+    # available in the store. Ideally they should be merged but the overlay FS
+    # doesn't work when the underlying directories change.
+    BindReadOnlyPaths = "/mnt/hut-nix-store:/nix/store";
+  };
+}
diff --git a/m/owl1/configuration.nix b/m/owl1/configuration.nix
index 5afda72..d21ccfd 100644
--- a/m/owl1/configuration.nix
+++ b/m/owl1/configuration.nix
@@ -5,6 +5,7 @@
     ../common/main.nix
     ../module/ceph.nix
     ../module/slurm-firewall.nix
+    ../module/slurm-hut-nix-store.nix
   ];
 
   # Select the this using the ID to avoid mismatches
diff --git a/m/owl2/configuration.nix b/m/owl2/configuration.nix
index 9636760..5fdabbe 100644
--- a/m/owl2/configuration.nix
+++ b/m/owl2/configuration.nix
@@ -5,6 +5,7 @@
     ../common/main.nix
     ../module/ceph.nix
     ../module/slurm-firewall.nix
+    ../module/slurm-hut-nix-store.nix
   ];
 
   # Select the this using the ID to avoid mismatches