Cannot access localhost:8123 when running in docker with network=host

[np03 (np)]

This helped me!!!

Homeassisant in docker unreachable using network mode host

Docker Desktop is a nice little package that wraps up a few docker components into one package, including Docker Engine, Docker Compose, a GUI, and a VM. Docker Engine is basically just the “docker” portion of the code without any additional bells and whistles. Its the core of Docker. Basically Docker Desktop runs a mini Virtual Machine that runs Docker Engine, which makes it nice for distributing to other Operating Systems, and it does some setup automatically. Docker Engine can only run on Li…

I uninstalled docker desktop and reinstalled only the docker engine in Ubuntu Linux.
The problem is with docker desktop it somehow closes the port.
I do not have firewall running in my ubuntu as well.
I needed to run my docker engine using sudo.

Note when you use port instead of network=host, the self discovery does not work as expected.