Build small docker image sizes
I was building a NextJS image with Docker and ended up with over 6gb file sizes.
Yikes
Bad
my initial, bloated Dockerfile looked like this
FROM node:18
WORKDIR /app
COPY . .
RUN yarn install
ENV NODE_ENV production
ENV PORT 3000
CMD ["yarn", "start"]
EXPOSE 3000
Better
use alpine versions
FROM node:18-alpine
WORKDIR /app
COPY . .
RUN yarn install
ENV NODE_ENV production
ENV PORT 3000
EXPOSE 3000
CMD ["yarn", "start"]
Multi Stage Build
multi stage builds can share files and reduce duplication during build process
FROM node:18-alpine as builder
WORKDIR /app
COPY yarn.lock .
COPY package.json .
RUN yarn
COPY . .
RUN yarn build
FROM node:18-alpine as runner
WORKDIR /app
COPY --from=builder /app/package.json .
COPY --from=builder /app/yarn.lock .
RUN yarn --production
COPY --from=builder /app/next.config.js .
COPY --from=builder /app/public ./public
COPY --from=builder /app/.next ./.next
EXPOSE 3000
CMD ["yarn", "start"]
BEST
Use a variable in your .env file
## Linux 64 bit
PRODUCTION_PLATFORM='linux/amd64'
## MacOS M1 Silicon
PRODUCTION_PLATFORM='linux/arm64/v8'
ARG PRODUCTION_PLATFORM
FROM --platform=$PRODUCTION_PLATFORM node:20-alpine AS base
FROM base as builder
WORKDIR /app
COPY yarn.lock .
COPY package.json .
RUN yarn install --frozen-lockfile
COPY . .
RUN yarn build
FROM base as runner
WORKDIR /app
COPY --from=builder /app/package.json .
COPY --from=builder /app/yarn.lock .
COPY --from=builder /app/next.config.js .
COPY --from=builder /app/public ./public
COPY --from=builder /app/node_modules ./node_modules
COPY --from=builder /app/.next ./.next
EXPOSE 3000
CMD ["yarn", "start"]
Standalone
In your next.config.mjs file, enable the standalone output for Next 14
export default {
// todo look into build optimization with `standalone` mode
output: "standalone",
...
Use a variable in your `.env` file
```env
## Linux 64 bit
PRODUCTION_PLATFORM='linux/amd64'
## MacOS M1 Silicon
PRODUCTION_PLATFORM='linux/arm64/v8'
ARG PRODUCTION_PLATFORM
FROM --platform=$PRODUCTION_PLATFORM node:20-alpine AS base
FROM base as builder
WORKDIR /app
COPY yarn.lock .
COPY package.json .
RUN yarn install --frozen-lockfile
COPY . .
RUN yarn build
FROM base as runner
WORKDIR /app
COPY --from=builder /app/package.json .
COPY --from=builder /app/yarn.lock .
COPY --from=builder /app/next.config.js .
COPY --from=builder /app/public ./public
COPY --from=builder /app/.next/standalone ./
COPY --from=builder /app/.next/static ./.next/static
EXPOSE 3000
CMD ["node", "server.js"]