Fix "Can't check kernel version" warning message

On Ubuntu only by default.

CHANGELOG.md

@@ -1,3 +1,10 @@
+## v2.3.0
+
+### Enhancements
+* Add variable/template to fix **kern**'s probe related message on Ubuntu
+  (`Can't check kernel version!`)
+    * See : https://bugs.launchpad.net/ubuntu/+source/linux/+bug/759725/comments/35
+
 ## v2.2.0
 
 ### Enhancements

defaults/main.yml

@@ -79,6 +79,13 @@ xymon_cli__plug_kern_path: '/etc/xymon/clientlaunch.d/kern.cfg'
 xymon_cli__plug_kern_tpl: 'etc/xymon/clientlaunch.d/kern.cfg.j2'
 xymon_cli__plug_kern_interval: '5m'
 
+### Related to "Ubuntu - Can't check kernel version" warning message
+### See : https://bugs.launchpad.net/ubuntu/+source/linux/+bug/759725/comments/35
+xymon_cli__plug_kern_fix: '{{ True if (ansible_distribution == "Ubuntu")
+                                   else False }}'
+xymon_cli__plug_kern_fix_path: '/etc/kernel/postinst.d/statoverride'
+xymon_cli__plug_kern_fix_tpl: 'etc/kernel/postinst.d/statoverride.j2'
+
                                                                    # ]]]
 ## Plugin libs [[[
 xymon_cli__plug_libs_state: true

tasks/main.yml

@@ -97,6 +97,19 @@
          xymon_cli__plug_manage|bool)
   notify: restart xymon-client service
 
+# Manage kern plugin [[[1
+- name: PLUGIN kern workaround
+  ansible.builtin.template:
+    src: '{{ xymon_cli__plug_kern_fix_tpl }}'
+    dest: '{{ xymon_cli__plug_kern_fix_path }}'
+    owner: root
+    group: root
+    mode: 0754
+  when: (xymon_cli__manage|bool and
+         xymon_cli__plug_manage|bool and
+         xymon_cli__plug_kern_fix|bool)
+  notify: restart xymon-client service
+
 # Manage net plugin [[[1
 - name: PLUGIN net config template
   ansible.builtin.template:

templates/etc/kernel/postinst.d/statoverride.j2

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+{# Use | comment to manage multilines #}
+# {{ ansible_managed | comment }}
+# Ansible template : {{ template_path }}
+#
+# Allow to fix the warning :
+#   "Kernel image /boot/vmlinuz… unreadable. Can't check kernel version!"
+
+# https://bugs.launchpad.net/ubuntu/+source/linux/+bug/759725
+# See comment #34 - https://bugs.launchpad.net/ubuntu/+source/linux/+bug/759725/comments/34
+
+set -e
+version="$1"
+if [ -z "$version" ]; then
+	exit 0
+fi
+exec dpkg-statoverride --force-statoverride-add --update --add root root 0644 "/boot/vmlinuz-${version}"