Understanding logs

Hi guys,
I would like to know how I can have more detailed logging about rancher.

When I type docker logs -f I hve a line spamming my logs every 30 seconds but I can’t find what it’s related to :

[details=logs]time=“2016-11-09T18:50:16+01:00” level=info msg="Stats auth failed: Error parsing stats token. Failing auth. Error: token is expired"
time=“2016-11-09T18:50:46+01:00” level=info msg="Stats auth failed: Error parsing stats token. Failing auth. Error: token is expired"
time=“2016-11-09T18:51:16+01:00” level=info msg="Stats auth failed: Error parsing stats token. Failing auth. Error: token is expired"
time=“2016-11-09T18:51:46+01:00” level=info msg="Stats auth failed: Error parsing stats token. Failing auth. Error: token is expired"
time=“2016-11-09T18:52:16+01:00” level=info msg="Stats auth failed: Error parsing stats token. Failing auth. Error: token is expired"
time=“2016-11-09T18:52:47+01:00” level=info msg="Stats auth failed: Error parsing stats token. Failing auth. Error: token is expired"
time=“2016-11-09T18:53:17+01:00” level=info msg="Stats auth failed: Error parsing stats token. Failing auth. Error: token is expired"
time=“2016-11-09T18:53:47+01:00” level=info msg=“Stats auth failed: Error parsing stats token. Failing auth. Error: token is expired”[/details]

Could you help please ?