Docker Template: Node.js

Summary

My unified docker template for Node.js apps. Supports:

Development Environment: --target dev
CI: --target test
Production Environment: --target release. Uses an intermediate build stage to prepare production builds. This helps to keep production image slim, containing only npm packages & code builds.
Installation of private npm packages from github repositories. Expects GITHUB_TOKEN as a docker build argument.

Dockerfile


# syntax=docker/dockerfile:1

# ---- Base ----
FROM node:16-alpine3.13 as base
ARG GITHUB_TOKEN
WORKDIR /app
COPY package.json ./
COPY yarn.lock ./

# ---- Dependencies ----
FROM base as dependencies
RUN apk add --no-cache openssh git
RUN if [[ "$GITHUB_TOKEN" != "" ]] ; then git config --global url."https://${GITHUB_TOKEN}@github.com/".insteadOf ssh://git@github.com ; fi
RUN mkdir -p -m 0600 ~/.ssh && ssh-keyscan github.com >> ~/.ssh/known_hosts
COPY . .

# ---- Development ----
FROM dependencies AS dev
ENV NODE_ENV=development
CMD yarn install && yarn start:dev

# ---- Test ----
FROM dependencies AS test
ENV NODE_ENV=test
RUN yarn install
ENTRYPOINT yarn test

# ---- Production Build ----
FROM dependencies as build
RUN yarn install
RUN NODE_ENV=production yarn build
RUN rm -rf node_modules && yarn install --production

# ---- Release ----
FROM base AS release
ENV NODE_ENV=production
COPY --from=build --chown=node:node  /app/dist ./dist
COPY --from=build --chown=node:node /app/node_modules ./node_modules
HEALTHCHECK CMD ls /proc/1/status || exit 1 
USER node
CMD ["yarn", "start"]

SSH using BuildKit

Docker also allows the Docker Engine to forward host SSH agent connections. This can be done as:


RUN --mount=type=ssh yarn install

  
  docker build --ssh default .

While this is the native docker solution to forward SSH agent, --ssh default argument cannot still be passed down using docker compose. This makes it cumbersome to use in projects with multiple services needing hot reloading.

I use it when I am working on a monorepo.

However, if I am working with multiple services using docker compose, I prefer adding GITHUB_TOKEN.