home: add timer for updating nix channels

home/home.nix

@@ -24,6 +24,7 @@ in {
     ./programs/zsh
 
     ./services/git-maintenance.nix
+    ./services/nix-channel-update.nix
 
     ./modules/colors.nix
     ./modules/shellAliases.nix

home/services/nix-channel-update.nix

@@ -0,0 +1,30 @@
+{ config, lib, ... }:
+{
+  # TODO: make these units run per channel
+  systemd.user.timers.update-nix-channels = {
+    Unit = {
+      Description = "Update nix channels";
+    };
+
+    Timer = {
+      Unit = "update-nix-channels.service";
+      OnCalendar = "daily";
+      Persistent = true;
+    };
+
+    Install = {
+      WantedBy = [ "timers.target" ];
+    };
+  };
+
+  systemd.user.services.update-nix-channels = {
+    Unit = {
+      Description = "Update nix channels";
+    };
+
+    Service = {
+      Type = "oneshot";
+      ExecStart = "${config.nix.package}/bin/nix-channel --update --verbose";
+    };
+  };
+}