Dockerfile Optimization — Reducing Image Size and Build Time

FROM node:20
WORKDIR /app
COPY . .
RUN npm install
RUN npm run build
EXPOSE 3000
CMD ["node", "dist/server.js"]

FROM node:20-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production
COPY . .
RUN npm run build

FROM node:20-alpine AS runner
WORKDIR /app

RUN addgroup -S appgroup && adduser -S appuser -G appgroup

COPY --from=builder /app/dist ./dist
COPY --from=builder /app/node_modules ./node_modules

USER appuser
EXPOSE 3000
CMD ["node", "dist/server.js"]

COPY package*.json ./
RUN npm ci

COPY src/ ./src/

node_modules
.git
.env
*.log
dist
coverage

RUN apt-get update && \
    apt-get install -y --no-install-recommends curl && \
    rm -rf /var/lib/apt/lists/*

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

DOCKER_BUILDKIT=1 docker build .

docker history myapp:latest

docker run --rm -it \
  -v /var/run/docker.sock:/var/run/docker.sock \
  wagoodman/dive myapp:latest