add ipv6 perm disable

notes.md

@@ -29,6 +29,10 @@ if ipv6 enabled
 ## /etc/sysctl.conf
 ```ini
 net.ipv6.conf.enable_ipv6 = 0
+
+net.ipv6.conf.all.disable_ipv6 = 1
+net.ipv6.conf.default.disable_ipv6 = 1
+
 ```
 
 <br>

preupgrade.yml

@@ -13,6 +13,18 @@
         - floppy
         - pata_acpi
 
+    - name: Disable IPv6 (will be left disabled post-IPU)
+      ansible.builtin.blockinfile:
+        path: /etc/sysctl.conf
+        append_newline: true
+        prepend_newline: true
+        block: |
+          net.ipv6.conf.all.disable_ipv6 = 1
+          net.ipv6.conf.default.disable_ipv6 = 1
+      notify: Sysctl_update
+      when:
+        - ipu_disable_ipv6 | default(false) | bool
+
     - name: Leapp Pre-Upgrade
       block:
         - name: Run Leapp pre-upgrade check
@@ -35,3 +47,10 @@
             msg: >
               Leapp pre-upgrade failed:\n
               {{ leapp_preupgrade['stdout_lines'] }}
+
+
+  handlers:
+    - name: Sysctl_update
+      ansible.builtin.command:
+        cmd: sysctl -p
+      changed_when: false