Description of problem:

The rabbitmq-limits validation fails on a freshly deployed overcloud. 
The reason seems to be that the call: https://github.com/openstack/tripleo-validations/blob/stable/train/roles/rabbitmq_limits/tasks/main.yml#L13 will return undefined on OSP16.1 while it returns a value in OSP13.

OSP13:

()[root@oc-ctl-0 /]# rabbitmqctl eval "erlang:system_info(version)."
"7.3.1.6"

()[root@oc-ctl-0 /]# rabbitmqctl eval 'proplists:get_value(max_fds,erlang:system_info(check_io)).'
65536
()[root@oc-ctl-0 /]# rabbitmqctl eval "erlang:system_info(check_io)."
[{name,erts_poll},
 {primary,epoll},
 {fallback,poll},
 {kernel_poll,epoll},
 {memory_size,64256},
 {total_poll_set_size,122},
 {fallback_poll_set_size,0},
 {lazy_updates,true},
 {pending_updates,0},
 {batch_updates,false},
 {concurrent_updates,true},
 {max_fds,65536},
 {active_fds,0}]


OSP16.1:

()[root@oc-ctl-0 /]# rabbitmqctl eval "erlang:system_info(version)."
"10.3.5.13"
()[root@oc-ctl-0 /]# rabbitmqctl eval 'proplists:get_value(max_fds, erlang:system_info(check_io)).'
undefined
()[root@oc-ctl-0 /]# rabbitmqctl eval "erlang:system_info(check_io)."
[[{name,erts_poll},
  {primary,poll},
  {kernel_poll,false},
  {memory_size,25240},
  {total_poll_set_size,1},
  {lazy_updates,true},
  {pending_updates,0},
  {batch_updates,false},
  {concurrent_updates,false},
  {fallback,true},
  {max_fds,65536},
  {active_fds,0},
  {poll_threads,0}],
 [{name,erts_poll},
  {primary,epoll},
  {kernel_poll,epoll},
  {memory_size,56},
  {total_poll_set_size,6},
  {lazy_updates,false},
  {pending_updates,0},
  {batch_updates,false},
  {concurrent_updates,true},
  {fallback,false},
  {max_fds,65536},
  {active_fds,0},
  {poll_threads,0}],
 [{name,erts_poll},
  {primary,epoll},
  {kernel_poll,epoll},
  {memory_size,57400},
  {total_poll_set_size,230},
  {lazy_updates,false},
  {pending_updates,0},
  {batch_updates,false},
  {concurrent_updates,true},
  {fallback,false},
  {max_fds,65536},
  {active_fds,0},
  {poll_threads,1}]]


Version-Release number of selected component (if applicable):

OSP16.1
How reproducible:


Steps to Reproduce:
1. Deploy overcloud
2. Run rabbitmq-limits validation: openstack tripleo validator run --validation rabbitmq-limits
3. Check the validation result

Actual results:

Validation fails

Expected results:

Validation should pass 

Additional info: