How does docker open port 2375 to provide external access to docker? about docker HOT 3 CLOSED

I don't understand this question, how is it related to OpenWrt?

from docker.

This is not related to OpenWrt. Just modify the docker daemon config file (by default /etc/docker/daemon.json):

{
    "hosts":[
                "tcp://0.0.0.0:2375",
                "unix:///var/run/docker.sock"
    ]
}

or
start dockerd with an -H flag like
dockerd -H unix:///var/run/docker.sock -H tcp://0.0.0.0:2375

from docker.

It has been handled. There is no such configuration file in the early version, such as a beat version of docker. After updating, it is found that there is such a configuration

from docker.