Assert that IP range is enough for the nodes (#8720)

* Assert that IP range is enough for the nodes 

Co-authored-by: Necatican Yıldırım <necaticanyildirim@gmail.com>

* Fixed whitespace

* Fixed errors

* Fixed errors

Co-authored-by: Necatican Yıldırım <necaticanyildirim@gmail.com>

roles/kubernetes/preinstall/tasks/0020-verify-settings.yml

@@ -183,6 +183,13 @@
     msg: "kube_pods_subnet cannot be the same network segment as kube_service_addresses"
   run_once: yes
 
+- name: "Check that IP range is enough for the nodes"
+  assert:
+    that:
+      - 2 ** (kube_network_node_prefix - kube_pods_subnet | ipaddr('prefix')) >= groups['k8s_cluster'] | length
+    msg: "Not enough IPs are available for the desired node count."
+  run_once: yes
+
 - name: Stop if unknown dns mode
   assert:
     that: dns_mode in ['coredns', 'coredns_dual', 'manual', 'none']