howitworksDocker kaise kaam karta hai? Laptop pe chali, server pe crash ka asli fix
Docker app ko uske runtime aur dependencies ke saath ek image mein pack karta hai, taaki laptop aur server par same chale. Example: optional chaining (?.) Node 14 se support hota hai; Node 12 server par SyntaxError: Unexpected token '.' aata hai. Dockerfile ki har instruction ek layer banati hai; koi layer badle toh woh aur uske baad ki layers rebuild hoti hain, pehle wali cache se aati hain. Image tag hokar registry (Docker Hub) par push hoti hai aur server par pull + run. Container host kernel par chalta isolated process hai: namespaces (network, mount, PID) alag view dete hain, cgroups CPU/memory limit karte hain. Rollback ke liye purana tag chalao; latest sirf default tag hai, newest ki guarantee nahi, production mein exact tag ya digest use karo.
Links
Aaj ye karo
- Dockerfile likho: FROM node:22, WORKDIR /app, COPY package*.json ./, RUN npm ci, COPY . ., CMD ["node", "server.js"].
- Build karo: docker build -t myapp:1.0 . (sirf code badlo aur dobara build karo: pehli layers CACHED dikhengi).
- Push karo: docker push <username>/myapp:1.0 (pehle docker login).
- Server par: docker pull <username>/myapp:1.0 aur docker run -p 3000:3000 <username>/myapp:1.0.
- Limit lagao: docker run --cpus=1 --memory=512m ...
- Rollback: purana tag chalao, jaise docker run <username>/myapp:1.0. Production mein exact tag ya @sha256 digest pin karo.
docker build -t myapp:1.0 .docker push <username>/myapp:1.0docker pull <username>/myapp:1.0docker run -p 3000:3000 --cpus=1 --memory=512m <username>/myapp:1.0docker images --digestsSources
docs.docker.com (overview, build cache, storage drivers, image pull), docs.npmjs.com, Node 12 optional chaining error reports; 6 Nov 2026 ko check kiya.