how can i change the server port in the host mode?

[terryxuwen]

--net=host

so i can't change the port by -p 4000:80

i edit the default and ttrss file in the image/etc/nginx/sites-available , change the listen port from 80 to 4000，commit a new image，and successfully docker start。but it does not work. i can‘t access ttrss by 80 or 4000 。’