feat(sterni/ingeborg): enable btrfs auto scrub

While we are at it, rename disk-checkup.nix to btrfs-auto-scrub.nix and
move it into //ops/modules. I originally wanted to have additionally
disk health related services in that module, but the btrfs scrub
functionality is nicely self-contained and reusable, so I think it makes
sense to have this in a more central location.

Change-Id: Iabdd62838eef009540ca71abafd921afda2a9b47
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10128
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI

ops/modules/btrfs-auto-scrub.nix

@@ -0,0 +1,25 @@
+# Automatically performs a scrub on all btrfs filesystems configured in
+# `config.fileSystems` on a daily schedule (by default). Activated by importing.
+{ config, lib, ... }:
+
+{
+  config = {
+    services = {
+      btrfs.autoScrub = {
+        enable = true;
+        interval = lib.mkDefault "daily";
+        # gather all btrfs fileSystems, extra ones can be added via the NixOS
+        # module merging mechanism, of course.
+        fileSystems = lib.concatLists (
+          lib.mapAttrsToList
+            (
+              _:
+              { fsType, mountPoint, ... }:
+              if fsType == "btrfs" then [ mountPoint ] else [ ]
+            )
+            config.fileSystems
+        );
+      };
+    };
+  };
+}

users/sterni/machines/edwin/default.nix

@@ -10,7 +10,7 @@
     ./hardware.nix
     ./network.nix
     # These modules configure services, websites etc.
-    ../../modules/disk-checkup.nix
+    (depot.path.origSrc + "/ops/modules/btrfs-auto-scrub.nix")
     ./minecraft.nix
     ./gopher.nix
     ./http/sterni.lv.nix

users/sterni/machines/ingeborg/default.nix

@@ -7,6 +7,8 @@
     # These modules touch things related to booting (filesystems, initrd network…)
     ./hardware.nix
     ./network.nix
+    # (More or less) pluggable service configuration
+    (depot.path.origSrc + "/ops/modules/btrfs-auto-scrub.nix")
   ];
 
   config = {

users/sterni/modules/disk-checkup.nix

@@ -1,25 +0,0 @@
-# TODO(sterni): configure smartd and alerts
-{ config, lib, ... }:
-
-{
-  config = {
-    services = {
-      btrfs.autoScrub = {
-        enable = true;
-        interval = "daily";
-        # gather all btrfs fileSystems and overwrite default
-        fileSystems = lib.mkForce (
-          lib.concatLists (
-            lib.mapAttrsToList
-              (
-                _:
-                { fsType, mountPoint, ... }:
-                if fsType == "btrfs" then [ mountPoint ] else [ ]
-              )
-              config.fileSystems
-          )
-        );
-      };
-    };
-  };
-}