nixos/hddfancontrol: loosen pwmPaths and disks types to str, nixos/hddtemp: allow command substitution for drives (#421862)

nixos/modules/hardware/sensor/hddtemp.nix

@@ -9,21 +9,26 @@ let
 
   cfg = config.hardware.sensor.hddtemp;
 
-  wrapper = pkgs.writeShellScript "hddtemp-wrapper" ''
+  script = ''
     set -eEuo pipefail
 
     file=/var/lib/hddtemp/hddtemp.db
 
-    drives=(${toString (map (e: ''$(realpath ${lib.escapeShellArg e}) '') cfg.drives)})
+    raw_drives=""
+    ${lib.concatStringsSep "\n" (map (drives: "raw_drives+=\"${drives} \"") cfg.drives)}
+    drives=""
+    for i in $raw_drives; do
+      drives+=" $(realpath $i)"
+    done
 
     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} \
+    ${pkgs.hddtemp}/bin/hddtemp ${lib.escapeShellArgs cfg.extraArgs} \
       --daemon \
       --unit=${cfg.unit} \
       --file=$file \
-      ''${drives[@]}
+      $drives
   '';
 
 in
@@ -77,9 +82,9 @@ in
       description = "HDD/SSD temperature";
       documentation = [ "man:hddtemp(8)" ];
       wantedBy = [ "multi-user.target" ];
+      inherit script;
       serviceConfig = {
         Type = "forking";
-        ExecStart = wrapper;
         StateDirectory = "hddtemp";
         PrivateTmp = true;
         ProtectHome = "tmpfs";

nixos/modules/services/hardware/hddfancontrol.nix

@@ -52,21 +52,30 @@ in
             {
               options = {
                 disks = lib.mkOption {
-                  type = lib.types.listOf lib.types.path;
+                  type = lib.types.listOf lib.types.str;
                   default = [ ];
                   description = ''
                     Drive(s) to get temperature from
+
+                    Can also use command substitution to automatically grab all matching drives; such as all scsi (sas) drives
                   '';
-                  example = [ "/dev/sda" ];
+                  example = [
+                    "/dev/sda"
+                    "`find /dev/disk/by-id -name \"scsi*\" -and -not -name \"*-part*\" -printf \"%p \"`"
+                  ];
                 };
 
                 pwmPaths = lib.mkOption {
-                  type = lib.types.listOf lib.types.path;
+                  type = lib.types.listOf lib.types.str;
                   default = [ ];
                   description = ''
                     PWM filepath(s) to control fan speed (under /sys), followed by initial and fan-stop PWM values
+                    Can also use command substitution to ensure the correct hwmonX is selected on every boot
                   '';
-                  example = [ "/sys/class/hwmon/hwmon2/pwm1:30:10" ];
+                  example = [
+                    "/sys/class/hwmon/hwmon2/pwm1:30:10"
+                    "`echo /sys/devices/platform/nct6775.656/hwmon/hwmon[[:print:]]`/pwm4:80:20"
+                  ];
                 };
 
                 logVerbosity = lib.mkOption {
@@ -151,9 +160,12 @@ in
         documentation = [ "man:hddfancontrol(1)" ];
         after = [ "hddtemp.service" ];
         wants = [ "hddtemp.service" ];
+        script =
+          let
+            argString = lib.strings.concatStringsSep " " (args cnf);
+          in
+          "${lib.getExe pkgs.hddfancontrol} -v ${cnf.logVerbosity} daemon ${argString}";
         serviceConfig = {
-          ExecStart = "${lib.getExe pkgs.hddfancontrol} -v ${cnf.logVerbosity} daemon ${lib.escapeShellArgs (args cnf)}";
-
           CPUSchedulingPolicy = "rr";
           CPUSchedulingPriority = 49;