Error: Unknown discovery type : 3

[bboreham]

Seen in Docker 1.12-rc2 logs when using Weave network (as an example of a remote driver; this issue does not appear to have anything to do with Weave):

Jun 25 20:57:53 host1 docker[15099]: time="2016-06-25T20:57:53.409535574Z" level=warning msg="Failed to set datapath keys in driver weavemesh: Unknown discovery type : 3"

This appears to be because agent.go calls DiscoverNew with type EncryptionKeysUpdate but the remote glue code errors on anything that is not NodeDiscovery.

[mrjana]

@bboreham Are you using docker swarm mode and trying to use a global scope plugin? If so, global scope plugins are not yet supported in 1.12 when running in swarm mode. The support may come in the future. But the current cluster mode formed with external k/v store will continue to support plugins.

[bboreham]

Yes, I did docker swarm init, but I was not using a global scope plugin. weavemesh, the driver referenced in the error message, is local scope.

I have a global scope plugin; it is listening, but I was not using it.

Is this "may be supported in the future" status documented somewhere?