From 65211f5afcc3637c55423b327157a5eae05dff67 Mon Sep 17 00:00:00 2001
From: Peter Hoeg <peter@hoeg.com>
Date: Sun, 31 Jan 2021 10:51:35 +0800
Subject: [PATCH] nixos/hddtemp: add support for HDD/SSD temperature montoring

---
 nixos/modules/hardware/sensor/hddtemp.nix | 81 +++++++++++++++++++++++
 nixos/modules/module-list.nix             |  1 +
 2 files changed, 82 insertions(+)
 create mode 100644 nixos/modules/hardware/sensor/hddtemp.nix

diff --git a/nixos/modules/hardware/sensor/hddtemp.nix b/nixos/modules/hardware/sensor/hddtemp.nix
new file mode 100644
index 000000000000..df3f75e229a2
--- /dev/null
+++ b/nixos/modules/hardware/sensor/hddtemp.nix
@@ -0,0 +1,81 @@
+{ config, lib, pkgs, ... }:
+let
+  inherit (lib) mkIf mkOption types;
+
+  cfg = config.hardware.sensor.hddtemp;
+
+  wrapper = pkgs.writeShellScript "hddtemp-wrapper" ''
+    set -eEuo pipefail
+
+    file=/var/lib/hddtemp/hddtemp.db
+
+    drives=(${toString (map (e: ''$(realpath ${lib.escapeShellArg e}) '') cfg.drives)})
+
+    cp ${pkgs.hddtemp}/share/hddtemp/hddtemp.db $file
+    ${lib.concatMapStringsSep "\n" (e: "echo ${lib.escapeShellArg e} >> $file") cfg.dbEntries}
+
+    exec ${pkgs.hddtemp}/bin/hddtemp ${lib.escapeShellArgs cfg.extraArgs} \
+      --daemon \
+      --unit=${cfg.unit} \
+      --file=$file \
+      ''${drives[@]}
+  '';
+
+in
+{
+  meta.maintainers = with lib.maintainers; [ peterhoeg ];
+
+  ###### interface
+
+  options = {
+    hardware.sensor.hddtemp = {
+      enable = mkOption {
+        description = ''
+          Enable this option to support HDD/SSD temperature sensors.
+        '';
+        type = types.bool;
+        default = false;
+      };
+
+      drives = mkOption {
+        description = "List of drives to monitor. If you pass /dev/disk/by-path/* entries the symlinks will be resolved as hddtemp doesn't like names with colons.";
+        type = types.listOf types.str;
+      };
+
+      unit = mkOption {
+        description = "Celcius or Fahrenheit";
+        type = types.enum [ "C" "F" ];
+        default = "C";
+      };
+
+      dbEntries = mkOption {
+        description = "Additional DB entries";
+        type = types.listOf types.str;
+        default = [ ];
+      };
+
+      extraArgs = mkOption {
+        description = "Additional arguments passed to the daemon.";
+        type = types.listOf types.str;
+        default = [ ];
+      };
+    };
+  };
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+    systemd.services.hddtemp = {
+      description = "HDD/SSD temperature";
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = {
+        Type = "forking";
+        ExecStart = wrapper;
+        StateDirectory = "hddtemp";
+        PrivateTmp = true;
+        ProtectHome = "tmpfs";
+        ProtectSystem = "strict";
+      };
+    };
+  };
+}
diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
index 30fdde780098..0dff21236e12 100644
--- a/nixos/modules/module-list.nix
+++ b/nixos/modules/module-list.nix
@@ -46,6 +46,7 @@
   ./hardware/cpu/intel-microcode.nix
   ./hardware/digitalbitbox.nix
   ./hardware/device-tree.nix
+  ./hardware/sensor/hddtemp.nix
   ./hardware/sensor/iio.nix
   ./hardware/keyboard/zsa.nix
   ./hardware/ksm.nix