omen: add zfsHealth module

Signed-off-by: magic_rb <magic_rb@redalder.org>

nixos/modules/zfs-health.nix

@@ -0,0 +1,159 @@
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}: let
+  cfg = config.zfs.health;
+  pool = {
+    config,
+    name,
+    ...
+  }: {
+    options = {
+      scrub = lib.mkOption {
+        type = with lib.types; nullOr str;
+      };
+
+      trim = {
+        secure = lib.mkOption {
+          type = lib.types.bool;
+          default = false;
+        };
+
+        rate = lib.mkOption {
+          type = with lib.types; nullOr int;
+          default = null;
+        };
+
+        schedule = lib.mkOption {
+          type = with lib.types; nullOr str;
+        };
+      };
+    };
+  };
+
+  zpool = lib.getExe' cfg.package "zpool";
+
+  trimPools = lib.filterAttrs (_: poolConfig: poolConfig.trim != null) cfg.pools;
+in {
+  options.zfs.health = {
+    enable = lib.mkEnableOption "Enable ZFS health assurance module.";
+
+    package = lib.mkOption {
+      type = lib.types.package;
+      default = config.boot.zfs.package;
+    };
+
+    pools = lib.mkOption {
+      type = with lib.types; attrsOf (submodule pool);
+      default = [];
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.services = lib.foldl (acc: attr: acc // attr) {} [
+      (lib.flip lib.mapAttrs' trimPools
+        (
+          pool: poolConfig:
+            lib.nameValuePair "zfs-health-trim-${pool}-resume" {
+              after = ["systemd-suspend.service"];
+              wantedBy = ["suspend.target"];
+
+              restartIfChanged = false;
+
+              script = ''
+                set -eo pipefail
+
+                if -e /var/run/zfs-health-trim-${pool}-suspended ; then
+                  systemctl start "zfs-healt-trim-${pool}.service"
+                  rm /var/run/zfs-health-trim-${pool}-suspended
+                fi
+              '';
+
+              serviceConfig = {
+                Type = "oneshot";
+              };
+            }
+        ))
+      (lib.flip lib.mapAttrs' trimPools
+        (
+          pool: poolConfig:
+            lib.nameValuePair "zfs-health-trim-${pool}-suspend" {
+              before = ["systemd-suspend.service"];
+              wantedBy = ["suspend.target"];
+
+              restartIfChanged = false;
+
+              script = ''
+                set -eo pipefail
+
+                if systemctl status "zfs-healt-trim-${pool}.service" ; then
+                  touch /var/run/zfs-health-trim-${pool}-suspended
+                fi
+              '';
+
+              serviceConfig = {
+                Type = "oneshot";
+              };
+            }
+        ))
+      (lib.flip lib.mapAttrs' trimPools
+        (pool: poolConfig:
+          lib.nameValuePair "zfs-health-trim-${pool}" {
+            after = ["multi-user.target"];
+
+            restartIfChanged = false;
+
+            preStop = ''
+              set -eo pipefail
+
+              if ${zpool} status ${pool} | grep -q trimming ; then
+                ${zpool} trim --suspend ${pool}
+
+                if ! [ -z $MAINPID ] ; then
+                  while kill -0 $MAINPID 2> /dev/null ; do
+                    sleep 10
+                  done
+                fi
+              fi
+            '';
+
+            script = ''
+              if ${zpool} status ${pool} | grep -q trimming ; then
+                echo "Trim already in progress, polling for completion"
+                while ${zpool} status ${pool} | grep trimming >/dev/null ; do
+                  sleep 60
+                done
+              else
+                ${zpool} trim ${pool} \
+                  --wait \
+                  ${lib.optionalString (poolConfig.trim.rate != null) "--rate ${toString poolConfig.trim.rate}"} \
+                  ${lib.optionalString poolConfig.trim.secure "--secure"}
+              fi
+
+              echo "Trim done!"
+              ${zpool} status ${pool}
+            '';
+
+            serviceConfig = {
+              Type = "oneshot";
+            };
+          }))
+    ];
+
+    systemd.timers = lib.pipe cfg.pools [
+      (lib.filterAttrs (_: poolConfig: poolConfig.trim != null))
+      (lib.mapAttrs'
+        (pool: poolConfig:
+          lib.nameValuePair "zfs-health-trim-${pool}" {
+            after = ["multi-user.target"];
+
+            timerConfig = {
+              OnCalendar = poolConfig.trim.schedule;
+              Persistent = true;
+            };
+          }))
+    ];
+  };
+}

nixos/systems/omen/default.nix

@@ -59,6 +59,7 @@ in {
           inputs.uk3s-nix.nixosModules.ucontainersNetwork
           inputs.notnft.nixosModules.default
           inputs.self.nixosModules.notnft
+          inputs.self.nixosModules.zfsHealth
           inputs.impermenance.nixosModules.impermanence
         ];
 

nixos/systems/omen/filesystems.nix

@@ -114,4 +114,14 @@ in {
       options = nfsOptions;
     };
   };
+
+  zfs.health = {
+    enable = true;
+
+    pools."omen-ssd" = {
+      trim = {
+        schedule = "Sun *-*-* 03:00:00";
+      };
+    };
+  };
 }