Dockerfile

# Build stage 1
# Install dependencies and build the code.
FROM node:17-alpine AS appBuild
ENV INSTALL_PATH /usr/src/app
RUN mkdir -p $INSTALL_PATH
WORKDIR $INSTALL_PATH


# Everything needed to setup dependencies
COPY package*.json .
RUN npm ci

# COPY rest of code
# NOTE: .dockerignore file reduces the scope of what gets copied here
COPY . .

# NOTE: What data REMAINS after a step becomes a cached layer.
# So cleaning dev dependencies reduces total image size.
RUN npm run build && npm prune --production

# Uncomment to debug what is in the final image and what is taking up the space
# RUN ls -lah
# RUN du -h -d 1 .

FROM node:17-alpine AS production
ENV INSTALL_PATH /usr/src/app
RUN mkdir -p $INSTALL_PATH
COPY --from=appBuild $INSTALL_PATH/node_modules $INSTALL_PATH/node_modules
COPY --from=appBuild $INSTALL_PATH/dist $INSTALL_PATH/dist

WORKDIR $INSTALL_PATH

EXPOSE 80
# NOTE: DO NOT RUN ["npm", "start"] as the ENTRYPOINT
# It does not forward the SIGTERM and SIGINT events to Node
# Requires dependency source-map-support to produce source-mapped stack traces
ENTRYPOINT [ "node", "-r", "source-map-support/register", "dist/server.js", "--abort-on-uncaught-exception" ]