feat: centralize longhorn config

nixos/common/k3s.nix

@@ -1,4 +1,5 @@
 {
+  pkgs,
   config,
   meta,
   ...
@@ -14,4 +15,14 @@
       else "https://${meta.server-addr}:6443";
     extraFlags = ["--disable=servicelb" "--disable=traefik" "--node-ip ${meta.zt-ip}" "--flannel-iface ztxh6lvd6t" "--flannel-backend=host-gw" "--tls-san ${meta.zt-ip}"];
   };
+
+  # For longhorn
+  environment.systemPackages = [ pkgs.nfs-utils ];
+  services.openiscsi = {
+    enable = true;
+    name = "iqn.2016-04.com.open-iscsi:${config.networking.hostName}";
+  };
+  systemd.tmpfiles.rules = [
+    "L+ /usr/local/bin - - - - /run/current-system/sw/bin/"
+  ];
 }