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Master Dockerfile Best Practices for Your Node.js App!
🧱 Layer caching matters: Placing COPY package*.json and RUN npm install before copying the rest avoids reinstalling dependencies every time your code changes.
🎯 Pin your base image: Using node:18 ensures stability. node:latest might break builds tomorrow.
🌎 ENV in containers ≠ safe secrets: ENV NODE_ENV=production is great — just don’t put real secrets here. Use Docker secrets or external config tools.
🔄 ENTRYPOINT + CMD: This combo gives flexibility. You lock in the runtime (node), but allow the script to be overridden (CMD [“server.js”]).
🔒 Minimize image bloat: For production, consider using multi-stage builds or node:18-alpine to reduce image size.

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Key Dockerfile optimization techniques for Node.js applications include strategic layer caching by copying package files before source code, pinning base image versions for stability, avoiding secrets in ENV variables, combining ENTRYPOINT and CMD for flexibility, and using multi-stage builds or Alpine images to minimize production image size.