How to Use Docker BuildKit for Faster Builds

Using Docker BuildKit for Faster Builds

BuildKit is Docker's next-generation build engine that provides significant performance improvements through parallel execution, better caching, and advanced features like build secrets and SSH forwarding.

Enable BuildKit

Set the environment variable or configure the Docker daemon on your Breeze:

# Per-command
DOCKER_BUILDKIT=1 docker build -t my-app .

# Permanent (daemon.json)
sudo tee /etc/docker/daemon.json <<EOF
{ "features": { "buildkit": true } }
EOF
sudo systemctl restart docker

Multi-Stage Caching

BuildKit caches each stage independently, skipping unchanged layers:

FROM node:20-alpine AS deps
WORKDIR /app
COPY package*.json ./
RUN npm ci --production

FROM node:20-alpine AS build
WORKDIR /app
COPY --from=deps /app/node_modules ./node_modules
COPY . .
RUN npm run build

FROM node:20-alpine
WORKDIR /app
COPY --from=build /app/dist ./dist
COPY --from=deps /app/node_modules ./node_modules
CMD ["node", "dist/server.js"]

Cache Mounts

Persist package manager caches across builds:

RUN --mount=type=cache,target=/root/.npm npm ci

Build Secrets

Safely pass secrets without embedding them in layers:

RUN --mount=type=secret,id=npmrc,target=/root/.npmrc npm ci

docker build --secret id=npmrc,src=$HOME/.npmrc -t my-app .

Parallel Builds

BuildKit automatically parallelizes independent stages, reducing total build time. Use docker buildx bake to build multiple images concurrently from a single configuration file.