Static web application in docker using nginx - localhost refused to connect

Docker file contains the following command

FROM nginx
COPY . /usr/share/nginx/html

To build my docker image i have used following command

docker build -t <tagName>/img .

To run the docker image

docker run -p 80:8080 <tagName>/img

But i am not able to lanch my static site in my browser . i am getting

This site can’t be reached
localhost refused to connect.