Patrole framework will always fail when running from remote machine, if policy file are not explicitly on remote machine.

Tempest has a capability to get operated from remote machine.
Being a tempest plugin, Patrole must have a feature to enable operate remotely.
In multi-node deployment, If we are running Patrole from controller node or if we are running Patrole from single node deployment then it will work perfectly.
As a part of RBAC process, Patrole uses policy file parsing.
But currently parsing feature is implemented in such a way that it will always try to make a default policy file path "/etc/<service>/policy.json".

case#1: custom policy file testing (where custom policy file was located at remote machine)-

In this case, On the remote machine, we have to put custom policy files at the location /etc/<service>/policy.json

case#2: Default policy testing -

As per current framework implementation, if we are running Patrole from remote machine (not part of OpenStack deployment), then still it will seek for policy file at the patch "/etc/<service>/policy.json" in case of default policy testing.
Becuase path is being constructed each time whether explicit 'path' is passed or not.