node server.js warning

[happyreacer]

I have start a Docker container. When i start an type node server.js and have follow output:

dev environment detected
info - soket.io started
&yet -- signal master is running at: http://localhost:8888
warn - error raised: Error: listen EADDRINUSE :::8888

whats wrong?

[VarolOkan]

The port 8888 is already in use.