A simple Dockerfile.

Dockerfile

# ensure the exact baseimage is used (exemplified below)
FROM node:lts-alpine@sha256:b2da3316acdc2bec442190a1fe10dc094e7ba4121d029cb32075ff59bb27390a

# install dumb-init for invoking docker
RUN apk add dumb-init

# optimize for production
ENV NODE_ENV production

WORKDIR /usr/src/app

# 'node' process owns the files now, not 'root'
COPY --chown=node:node . .

# do not install dev dependencies
RUN yarn install --production=true

# make 'node' as the process owner, not 'root'
USER node

# prevent starting process as PID1 by using dumb-init
CMD ["dumb-init", "node", "server.js"]