Running docker container not accessible from host (localhost:8081)

Question

Using Ubuntu.

Based on this guide:

https://www.freecodecamp.org/news/how-to-use-routing-in-vue-js-to-create-a-better-user-experience-98d225bbcdd9/

I have created a minimal vuejs project with below project structure:

https://github.com/dev-samples/samples/tree/master/vuejs-001

frontend-router/
  build/
  config/
  src/
  static/
  test/
  build.sh
  Dockerfile.dev
  package-lock.json
  package.json

Where:

Dockerfile.dev

FROM node:10
RUN apt install curl
RUN mkdir /app

# add `/app/node_modules/.bin` to $PATH
ENV PATH /app/node_modules/.bin:$PATH

# install and cache app dependencies
COPY package.json /app/package.json

# make the 'app' folder the current working directory before running npm install
WORKDIR /app

RUN npm install
CMD [ "npm", "run", "dev" ]

I am building the image and running the container from that image with:

docker build -t frontend-router-image -f Dockerfile.dev .
docker rm -f frontend-router-container

docker run -it -p 8081:8080 -v ${PWD}:/app/ -v /app/node_modules --name frontend-router-container frontend-router-image

which gives:

DONE  Compiled successfully in 1738ms                                                                                                                                                    3:49:45 PM

 I  Your application is running here: http://localhost:8080

Since I add -p 8081:8080 to docker run command I would expect that I can access the application from my host browser on:

http://localhost:8081/

but it just gives below error:

I works fine when I run it with vanilla npm from my host. But why can't I access the application when its run from inside a docker container?

Source code here:

https://github.com/dev-samples/samples/tree/master/vuejs-001

As suggested below I have tried:

$ docker ps
CONTAINER ID        IMAGE                   COMMAND                  CREATED             STATUS              PORTS                    NAMES
e011fb9e39e8        frontend-router-image   "docker-entrypoint.s…"   12 seconds ago      Up 9 seconds        0.0.0.0:8081->8080/tcp   frontend-router-container

$ docker run -it --rm --net container:frontend-router-container nicolaka/netshoot ss -lnt
State     Recv-Q    Send-Q       Local Address:Port        Peer Address:Port    
LISTEN    0         128              127.0.0.1:8080             0.0.0.0:*       

For comparison this project works fine:

https://github.com/dev-samples/samples/tree/master/vuejs-002

Meaning that when I run a container I can access the web application on my host browser on localhost:8081

Answer 1

Based on this:

https://github.com/webpack/webpack-dev-server/issues/547

and:

https://dev.to/azawakh/don-t-forget-to-give-host-0-0-0-0-to-the-startup-option-of-webpack-dev-server-using-docker-1483

https://pythonspeed.com/articles/docker-connection-refused/

It works if I change:

host: 'localhost', // can be overwritten by process.env.HOST

to:

host: '0.0.0.0', // can be overwritten by process.env.HOST

in the file: /frontend-router/config/index.js