Docker File

Create this file with the name Dockerfile and put into your project root folder.

# specify the node base image with your desired version node:<version>
FROM node:8

WORKDIR /app

RUN chown -R node:node /usr/local/lib/node_modules
RUN chown -R node:node /usr/local/bin
USER node

RUN npm install node-red -g
RUN npm install node-red-node-mongodb -g
RUN npm i node-red/node-red-dashboard -g

# port 1880 for node-red-dashboard
EXPOSE 1880

CMD node-red

Important in the Docker File

You need to include the -g behind, as if you don't the package won't be installed.

RUN npm install node-red -g
RUN npm install node-red-node-mongodb -g
RUN npm i node-red/node-red-dashboard -g

However, there will be permission error if you just do that. So you need to change the owner and switch the user before that.

RUN chown -R node:node /usr/local/lib/node_modules
RUN chown -R node:node /usr/local/bin
USER node

The Joy

Then you can build using docker build -t nodejs .
After running the docker image using docker run -it -p 1880:1880 nodejs
You can now access the node-red in your browser.
Btw, you could map multiple ports from the container to host by using multiple -p option.