How to expose port to external host in docker?

Question

I am trying to expose a port in docker container, and try to connect application from external host but i am unable to connect.

curl request:

curl http://localhost:4400
curl: (56) Recv failure: Connection reset by peer

run command:

docker run -p 4400:3002  dev/my-node-app

Dockerfile:

FROM ubuntu:20.04

RUN apt-get update; \
    apt-get install -y curl gnupg; \
    curl -sL https://deb.nodesource.com/setup_10.x | bash -; \
    apt-get install -y nodejs; \
    rm -rf /var/lib/apt/lists/*

WORKDIR /usr/src/app

COPY . .

EXPOSE 3002

ENTRYPOINT ["npm", "run", "server:dev"]

Also tried below Dockerfile

FROM node:12.19.0

# Create app directory
WORKDIR /usr/src/app

# Install app dependencies
# A wildcard is used to ensure both package.json AND package-lock.json are copied
# where available (npm@5+)
COPY package*.json ./

RUN npm install
# If you are building your code for production
# RUN npm ci --only=production

# Bundle app source
COPY . .

EXPOSE 3002
CMD ["npm", "run", "server:dev"]

But now getting error:

Module build failed: Error: /lib/x86_64-linux-gnu/libm.so.6: version `GLIBC_2.29' not found (required by /usr/src/app/node_modules/node-sass/vendor/linux-x64-64/binding.node)

I think i am running it correctly but somehow there is an error in my Dockerfile, if anyone help me I'd really be grateful.

Thanks

Answer 1

curl http://localhost:4400
curl: (56) Recv failure: Connection reset by peer

It indicates that port does not point to an application.

The application is pointing to 127.0.0.1, which should be pointing to 0.0.0.0 inside Docker.