All credit goes to the original author: koind/docker-simple-webserver | Github Repo
It just made sense for us to include this in our repo as standalone files as opposed to including the original repo in ours as a submodule.
Instructions from readme in original repo as below.
$ docker build -t webserver .
$ docker run -d -p 8080:8080 webserver
FROM debian:9.3-slim
RUN rm /bin/sh && ln -s /bin/bash /bin/sh
RUN apt-get update \
&& apt-get install -y curl
ENV NVM_DIR /usr/local/nvm
ENV NODE_VERSION 8.9.4
RUN curl --silent -o- https://raw.githubusercontent.com/creationix/nvm/v0.31.2/install.sh | bash
RUN source ~/.bashrc && nvm install $NODE_VERSION && nvm alias default $NODE_VERSION && nvm use default
ENV NODE_PATH $NVM_DIR/v$NODE_VERSION/lib/node_modules
ENV PATH $NVM_DIR/versions/node/v$NODE_VERSION/bin:$PATH
RUN node -v
RUN npm -v
RUN npm install express
COPY . /var/www/html
WORKDIR /var/www/html
EXPOSE 8080
CMD node webserver.js