diff --git a/bootstrap/cluster/main.tf b/bootstrap/cluster/main.tf
index da49e72..ae45875 100644
--- a/bootstrap/cluster/main.tf
+++ b/bootstrap/cluster/main.tf
@@ -28,8 +28,20 @@ resource "null_resource" "kubeadm_control_plane" {
     command     = <<EOT
 set -euo pipefail
 
-sudo apt-get update
-sudo apt-get install -y curl open-iscsi nfs-common
+install_missing_packages() {
+  missing_packages=""
+  for package in "$@"; do
+    if ! dpkg-query -W -f='$${Status}' "$package" 2>/dev/null | grep -q "install ok installed"; then
+      missing_packages="$missing_packages $package"
+    fi
+  done
+  if [ -n "$missing_packages" ]; then
+    sudo apt-get update
+    sudo apt-get install -y --no-install-recommends $missing_packages
+  fi
+}
+
+install_missing_packages open-iscsi nfs-common
 sudo systemctl enable --now iscsid
 sudo systemctl enable kubelet || true
 
@@ -151,8 +163,20 @@ resource "null_resource" "kubeadm_worker" {
       <<EOT
 set -eu
 
-sudo apt-get update
-sudo apt-get install -y curl open-iscsi nfs-common
+install_missing_packages() {
+  missing_packages=""
+  for package in "$@"; do
+    if ! dpkg-query -W -f='$${Status}' "$package" 2>/dev/null | grep -q "install ok installed"; then
+      missing_packages="$missing_packages $package"
+    fi
+  done
+  if [ -n "$missing_packages" ]; then
+    sudo apt-get update
+    sudo apt-get install -y --no-install-recommends $missing_packages
+  fi
+}
+
+install_missing_packages open-iscsi nfs-common
 sudo systemctl enable --now iscsid
 sudo systemctl enable kubelet || true
 
@@ -209,7 +233,7 @@ for path in $pv_dirs; do
   sudo chmod 0775 "$path"
 done
 
-if [ -f /etc/kubernetes/kubelet.conf ] && ! curl -fsS --max-time 5 http://127.0.0.1:10248/healthz >/dev/null 2>&1; then
+if [ -f /etc/kubernetes/kubelet.conf ] && ! timeout 5 bash -c 'exec 3<>/dev/tcp/127.0.0.1/10248; printf "GET /healthz HTTP/1.0\r\n\r\n" >&3; grep -q ok <&3' >/dev/null 2>&1; then
   sudo kubeadm reset --force || true
   sudo systemctl stop kubelet 2>/dev/null || true
   sudo rm -rf /etc/kubernetes/ /var/lib/kubelet/ /var/lib/cni/ /etc/cni/net.d