Run docker daemon in debug mode

Simple way:

dockerd

or with more verbosity:

dockerd --debug

Make it listen on network interface:

dockerd --debug --host=tcp://192.168.1.10:2375

Make it listen with TLS:

dockerd --debug --host=tcp://192.168.1.10:2376 \
--tls=true \
--tlscert=/var/docker/server.pem \
--tlskey=/var/docker/serverkey.pem

Make the same but with daemon configuration file:
Edit /etc/docker/daemon.json:

{
"debug": true,
"hosts": ["tcp://192.168.1.10:2376"]
"tls": true,
"tlscert": "/var/docker/server.pem",
"tlskey": "/var/docker/serverkey.pem"
}