Fancontrol: add test etc from #70933 (#72065)

* lm_sensors: add fancontrol module + nixos test

fancontrol is a small script that checks temperature sensors and adapts
fan speeds accordingly. It reads a text config file that can be
auto-generated by running the pwmconfig wizard on the live system.

3 files changed, 45 insertions, 20 deletions

diff --git a/nixos/modules/services/hardware/fancontrol.nix b/nixos/modules/services/hardware/fancontrol.nix
index 616e4add31e..bb4541a784d 100644
--- a/nixos/modules/services/hardware/fancontrol.nix
+++ b/nixos/modules/services/hardware/fancontrol.nix
@@ -4,42 +4,41 @@ with lib;
 
 let
   cfg = config.hardware.fancontrol;
-  configFile = pkgs.writeText "fan.conf" cfg.config;
-
-in {
+  configFile = pkgs.writeText "fancontrol.conf" cfg.config;
 
+in{
   options.hardware.fancontrol = {
-    enable = mkEnableOption "fancontrol (requires fancontrol.config)";
+    enable = mkEnableOption "software fan control (requires fancontrol.config)";
 
     config = mkOption {
-      type = types.lines;
       default = null;
+      type = types.lines;
+      description = "Fancontrol configuration file content. See <citerefentry><refentrytitle>pwmconfig</refentrytitle><manvolnum>8</manvolnum></citerefentry> from the lm_sensors package.";
       example = ''
         # Configuration file generated by pwmconfig
-        INTERVAL=1
-        DEVPATH=hwmon0=devices/platform/nct6775.656 hwmon1=devices/pci0000:00/0000:00:18.3
-        DEVNAME=hwmon0=nct6779 hwmon1=k10temp
-        FCTEMPS=hwmon0/pwm2=hwmon1/temp1_input
-        FCFANS=hwmon0/pwm2=hwmon0/fan2_input
-        MINTEMP=hwmon0/pwm2=25
-        MAXTEMP=hwmon0/pwm2=60
-        MINSTART=hwmon0/pwm2=25
-        MINSTOP=hwmon0/pwm2=10
-        MINPWM=hwmon0/pwm2=0
-        MAXPWM=hwmon0/pwm2=255
+        INTERVAL=10
+        DEVPATH=hwmon3=devices/virtual/thermal/thermal_zone2 hwmon4=devices/platform/f71882fg.656
+        DEVNAME=hwmon3=soc_dts1 hwmon4=f71869a
+        FCTEMPS=hwmon4/device/pwm1=hwmon3/temp1_input
+        FCFANS= hwmon4/device/pwm1=hwmon4/device/fan1_input
+        MINTEMP=hwmon4/device/pwm1=35
+        MAXTEMP=hwmon4/device/pwm1=65
+        MINSTART=hwmon4/device/pwm1=150
+        MINSTOP=hwmon4/device/pwm1=0
       '';
-      description = "Contents for configuration file. See <citerefentry><refentrytitle>pwmconfig</refentrytitle><manvolnum>8</manvolnum></citerefentry>.";
     };
   };
 
-
   config = mkIf cfg.enable {
     systemd.services.fancontrol = {
-      description = "Fan speed control from lm_sensors";
+      unitConfig.Documentation = "man:fancontrol(8)";
+      description = "software fan control";
       wantedBy = [ "multi-user.target" ];
+      after = [ "lm_sensors.service" ];
+
       serviceConfig = {
         Type = "simple";
-        ExecStart = "${pkgs.lm_sensors}/bin/fancontrol ${configFile}";
+        ExecStart = "${pkgs.lm_sensors}/sbin/fancontrol ${configFile}";
       };
     };
   };
diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index 10564e063c6..22270501dc1 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -81,6 +81,7 @@ in
   env = handleTest ./env.nix {};
   etcd = handleTestOn ["x86_64-linux"] ./etcd.nix {};
   etcd-cluster = handleTestOn ["x86_64-linux"] ./etcd-cluster.nix {};
+  fancontrol = handleTest ./fancontrol.nix {};
   ferm = handleTest ./ferm.nix {};
   firefox = handleTest ./firefox.nix {};
   firewall = handleTest ./firewall.nix {};
diff --git a/nixos/tests/fancontrol.nix b/nixos/tests/fancontrol.nix
new file mode 100644
index 00000000000..83ddbb54c5b
--- /dev/null
+++ b/nixos/tests/fancontrol.nix
@@ -0,0 +1,25 @@
+import ./make-test.nix ({ pkgs, ... } : {
+  name = "fancontrol";
+
+  machine =
+    { ... }:
+    { hardware.fancontrol.enable = true;
+      hardware.fancontrol.config = ''
+        INTERVAL=42
+        DEVPATH=hwmon1=devices/platform/dummy
+        DEVNAME=hwmon1=dummy
+        FCTEMPS=hwmon1/device/pwm1=hwmon1/device/temp1_input
+        FCFANS=hwmon1/device/pwm1=hwmon1/device/fan1_input
+        MINTEMP=hwmon1/device/pwm1=25
+        MAXTEMP=hwmon1/device/pwm1=65
+        MINSTART=hwmon1/device/pwm1=150
+        MINSTOP=hwmon1/device/pwm1=0
+      '';
+    };
+
+  # This configuration cannot be valid for the test VM, so it's expected to get an 'outdated' error.
+  testScript = ''
+    $machine->waitForUnit("fancontrol.service");
+    $machine->waitUntilSucceeds("journalctl -eu fancontrol | grep 'Configuration appears to be outdated'");
+  '';
+})