how to publish a docker container port to one of the random available port in the host-CodePudding

I tried to do the following:

docker run --expose 8765 --publish-all -it nginx

But this also exposes 80 along with port 8765

[root@centos7]# docker port f4b608998815
80/tcp -> 0.0.0.0:49156
80/tcp -> :::49156
8765/tcp -> 0.0.0.0:49155
8765/tcp -> :::49155

How to publish port 8765 to one of the random available ports in the host without specifying where to?

CodePudding user response：

The nginx base image already declares EXPOSE 80 and there's no way to un-expose a port, so if you use the docker run -P or --publish-all option to publish every exposed port, it will always be published alongside your manually-exposed port.

You can use the lowercase docker run -p option with only a single port number to publish that port on an arbitrary host port instead:

docker run -p 8765 -d nginx

Since Docker containers internally won't have port conflicts with each other, you may want to just use the default HTTP port 80, matching the standard Nginx config. The --expose --publish-all combination is pretty much the only actual effect of docker run --expose, and you can get the same thing with --port; you pretty much never need the docker run --expose option.