Dockerizing a web app using Nginx

Dockerfile

# https://docs.docker.com/engine/userguide/eng-image/multistage-build/
# The following example shows a way to bundle a node package & serve it using Nginx,
# while keeping the image size small & the image build time shorter, using
# the Multi-Stage Builds

########### Stage 0
# the node 8 alpine image is ~63MB, while the node image is around ~670MB
# the alpine image is resource efficient, smaller in bundle size 
# saves downloading time & precious bandwidth
FROM node:8.0.0-alpine

# (optional) required if you have packages directly 
# being installed from a github repo
RUN apk add --update git

# docker will again download the dependencies 
# during the `npm i` instead of using cache even 
# if there is no change in package.json
# copy ONLY the package.json
# to make sure cache only bursts if we update package.json
WORKDIR /usr/src/app
COPY package.json /usr/src/app/package.json
RUN npm i

# now copying the source is fine,
# just before the build step, 
# since the dependencies have been cached
COPY . /usr/src/app
RUN npm run build

########### Stage 1
FROM nginx:1.13.0

# instead of copying the build folder from the local system, 
# we copy it from the previous step 
COPY --from=0 /usr/src/app/build /usr/share/nginx/html

RUN rm /etc/nginx/nginx.conf
RUN rm /etc/nginx/conf.d/*

COPY config/nginx/nginx.conf /etc/nginx/nginx.conf
COPY config/nginx/conf.d/client.conf /etc/nginx/conf.d/client.conf

VOLUME /etc/nginx/conf.d/

EXPOSE 80