Failed to find a usable hardware address from the network interfaces

Question

I'm getting the following warning when running Aleph (which uses Netty) as a websever inside a Docker container:

WARNING: Failed to find a usable hardware address from the network interfaces; using random bytes: 75:62:7f:9b:c6:52:63:4b

I'm starting the server using:

(defn -main [& args]
  (http/start-server app {:port 3000}))

And I've also tried:

(defn -main [& args]
  (http/start-server app {:socket-address (java.net.InetSocketAddress. "0.0.0.0" 3000)}))

but still I get the same warning.

The warning only happens inside a docker container. I can run the server in my host without the warning. I also won't get the warning if when I run the container I use docker run --net host webserver.

The really weird thing is, despite the warning everything looks to be running fine. The correct ports are bound and the server is running correctly. Does anyone have any idea why I get this warning?