some monit fixes. add fail2ban monit dist conf file and rootfs check. dont generate invalid password.

roles/monitoring/defaults/main.yml

 
 # must match values in roles/common
 monit_admin_username: "{{ main_user_name }}"
-monit_admin_password: "{{ lookup('password', secret + '/' + 'monit_admin_password length=16') }}"
+monit_admin_password: "{{ lookup('password', secret + '/' + 'monit_admin_password length=16 chars=hexdigits') }}"
 
 monit_page_public: 1
 monit_subdomain: status

roles/monitoring/templates/etc_monit_monitrc.j2

 #    if inode usage > 99% then stop
 #    group server
 #
+
+check filesystem rootfs with path /
+    if space usage > 80% for 5 times within 15 cycles then alert
+    if space usage > 99% then alert
+    if inode usage > 80% for 5 times within 15 cycles then alert
+    if inode usage > 99% then alert
+    group server
+
 #
 ## Check a file's timestamp. In this example, we test if a file is older
 ## than 15 minutes and assume something is wrong if its not updated. Also,
 ## It is possible to include additional configuration parts from other files or
 ## directories.
 #
-   include /etc/monit/conf.d/*
 
+include /etc/monit/conf.d/*
+include /etc/monit/monitrc.d/*