node.js - Dockerfile: how to forward ports?

Question

I have a nodejs application. It runs in a container. I need to forward ports to the host machine. I ask for your help.

Dockerfile:

FROM node:14
WORKDIR /usr/src/app
COPY . .
RUN yarn
EXPOSE 4200

try:

docker run -p 127.0.0.1:4200:4200  -t -d --name vub vub
# or
docker run -p 4200:4200  -t -d --name vub vub

My application is running on port 4200. The operation of the application can be checked through

curl http://localhost:4200/

In the container, the application works correctly.

Why can't I see the application on the host machine(http://localhost:4200/)? How to fix it?

question from:https://stackoverflow.com/questions/65846526/dockerfile-how-to-forward-ports

Answer 1

You should make sure that there's a server running, with express or something responsible for the same functionalities. If all you're doing is printing a "hello world" on the terminal the container will exit.

Your question could be improved with the full source code.