move to systemd-timers

Signed-off-by: ahuston-0 <aliceghuston@gmail.com>

systems/palatine-hill/configuration.nix

@@ -6,10 +6,10 @@
 }:
 {
   imports = [
-    ./cron
-    ./networking.nix
-    ./zfs.nix
     ./hydra.nix
+    ./networking.nix
+    ./nextcloud.nix
+    ./zfs.nix
   ];
 
   programs.git.lfs.enable = false;

systems/palatine-hill/nextcloud.nix

@@ -0,0 +1,37 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+{
+  systemd.timers."nextcloud-pre-generate" = {
+    wantedBy = [ "timers.target" ];
+    timerConfig = {
+      OnBootSec = 600;
+      OnUnitActiveSec = 600;
+      Unit = "nextcloud-pre-generate.service";
+    };
+  };
+
+  systemd.services."nextcloud-pre-generate" = {
+    requires = [
+      "docker.service"
+      "multi-user.target"
+    ];
+    after = [
+      "docker.service"
+      "multi-user.target"
+    ];
+    description = "incrementally pre-generates previews on nextcloud";
+    serviceConfig = {
+      Type = "oneshot";
+      DynamicUser = "yes";
+      Group = "docker";
+      ExecStart = ''
+        docker ps --format "{{.Names}}" | grep -q "^nextcloud-nextcloud-1$" && docker exec --user www-data nextcloud-nextcloud-1 php occ preview:pre-generate
+      '';
+    };
+  };
+}