Docker 容器优化：从 1.2GB 到 80MB

问题

接手一个 Node.js 项目时，发现 Docker 镜像高达 1.2GB。CI/CD 流水线每次构建都要十几分钟。

分析

# 原始 Dockerfile
FROM node:18
WORKDIR /app
COPY . .
RUN npm install
RUN npm run build
CMD ["node", "dist/index.js"]

问题显而易见：包含了完整的构建工具链、devDependencies 和源代码。

优化

第一步：多阶段构建

FROM node:18-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build

FROM node:18-alpine
WORKDIR /app
COPY --from=builder /app/dist ./dist
COPY --from=builder /app/node_modules ./node_modules
CMD ["node", "dist/index.js"]

第二步：精简依赖

只复制生产依赖：

FROM node:18-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build
RUN npm prune --production

FROM node:18-alpine
WORKDIR /app
COPY --from=builder /app/dist ./dist
COPY --from=builder /app/node_modules ./node_modules
CMD ["node", "dist/index.js"]

第三步：distroless

终极优化——使用 distroless 基础镜像：

最终镜像：80MB。

小的镜像意味着更快的部署、更低的安全风险和更少的存储成本。