Harden Ubuntu VM update script readiness checks

scripts/ubuntu-vm-security-update.sh

@@ -109,8 +109,30 @@ ensure_service_enabled_and_restarted() {
   run systemctl restart "$service"
 }
 
+wait_for_fail2ban_ready() {
+  local attempts=10
+  local delay_seconds=1
+  local i
+
+  if [[ "$DRY_RUN" == "true" ]]; then
+    log "DRY RUN: skipping fail2ban readiness check"
+    return 0
+  fi
+
+  for ((i = 1; i <= attempts; i++)); do
+    if fail2ban-client ping >/dev/null 2>&1; then
+      log "fail2ban is ready"
+      return 0
+    fi
+    sleep "$delay_seconds"
+  done
+
+  return 1
+}
+
 detect_ssh_port() {
   local detected_port=""
+  local sshd_output=""
 
   if [[ -n "$SSH_PORT_OVERRIDE" ]]; then
     echo "$SSH_PORT_OVERRIDE"
@@ -118,7 +140,10 @@ detect_ssh_port() {
   fi
 
   if command -v sshd >/dev/null 2>&1; then
-    detected_port="$(sshd -T 2>/dev/null | awk '$1 == "port" {print $2; exit}')"
+    if sshd_output="$(sshd -T 2>/dev/null)"; then
+      detected_port="$(printf '%s\n' "$sshd_output" | awk '$1 == "port" {print $2}')"
+      detected_port="$(printf '%s\n' "$detected_port" | head -n 1)"
+    fi
   fi
 
   if [[ -z "$detected_port" ]] && [[ -f /etc/ssh/sshd_config ]]; then
@@ -330,7 +355,8 @@ EOF
 ensure_service_enabled_and_restarted fail2ban
 
 if [[ "$DRY_RUN" == "false" ]] && have_systemd && command -v fail2ban-client >/dev/null 2>&1; then
-  fail2ban-client ping | tee -a "$LOG_FILE" || die "fail2ban-client ping failed"
+  wait_for_fail2ban_ready || die "fail2ban-client ping failed"
+  fail2ban-client ping | tee -a "$LOG_FILE"
 fi
 
 log "Checking package integrity database availability"