Dockerfile

# syntax=docker/dockerfile:1
#RATHER THAN CREATING ONCE DOCKERFILE FOR PROD AND ANOTHER FOR DEV,YOU CAN USE ONE-MULTI STAGE DOCKERFILE FOR BOTH

# Comments are provided throughout this file to help you get started.
# If you need more help, visit the Dockerfile reference guide at
# https://docs.docker.com/go/dockerfile-reference/

# Want to help us make this template better? Share your feedback here: https://forms.gle/ybq9Krt8jtBL3iCk7

ARG NODE_VERSION=20.10.0
#FROM .... as base: refer to this build stage in other build stages
FROM node:${NODE_VERSION}-alpine as base
WORKDIR /usr/src/app
EXPOSE 3000
# Use production node environment by default.


# Download dependencies as a separate step to take advantage of Docker's caching.
# Leverage a cache mount to /root/.npm to speed up subsequent builds.
# Leverage a bind mounts to package.json and package-lock.json to avoid having to copy them into
# into this layer.
FROM base as dev
RUN --mount=type=bind,source=package.json,target=package.json \
    --mount=type=bind,source=package-lock.json,target=package-lock.json \
    --mount=type=cache,target=/root/.npm \
    npm ci --include=dev

# Run the application as a non-root user.
USER node

# Copy the rest of the source files into the image.
COPY . .
CMD npm run dev


# Run the application.

FROM base as prod
RUN --mount=type=bind,source=package.json,target=package.json \
    --mount=type=bind,source=package-lock.json,target=package-lock.json \
    --mount=type=cache,target=/root/.npm \
    npm ci --omit=dev
USER node
COPY . .
CMD node src/index.js


FROM base as test
ENV NODE_ENV test
RUN --mount=type=bind,source=package.json,target=package.json \
    --mount=type=bind,source=package-lock.json,target=package-lock.json \
    --mount=type=cache,target=/root/.npm \
    npm ci --include=dev
USER node
COPY . .
RUN npm run test 
#Used RUN instead of CMD because:
    #CMD runs when container runs and RUN runs when image is being built and the build will fail if test fails.