How do I map a port on a container to the host?

Question

I'm trying to run a container described by the following Dockerfile:

FROM node:11.4.0

RUN npm install -g sh
RUN npm install -g json-server

WORKDIR /data
VOLUME /data
COPY db.json /data

CMD json-server --watch db.json --port 3001

and specifying the listening port by running:

 docker run -it -p 3001:3001 abelalejandro/json-server:final

The container seems to be running fine and json-server is telling me it is serving my requests on port 3001 yet I can't get any joy when browsing http://localhost:3001

Am I missing something on publishing/exposing ports?

Answer 1

It is binding to localhost instead of 0.0.0.0 (any host).

You can change that by setting:

CMD json-server --watch db.json --host 0.0.0.0 --port 3001

I'm assuming you are using https://github.com/typicode/json-server .