deployment-docker

name	deployment-docker
description	Docker images, container setup, Docker Compose, multi-stage builds for Resource-Adda. Use when containerizing the app, setting up Docker Compose, building images, or deploying containers.

Deployment Docker

When to Use

• Building Docker images for backend/frontend
• Setting up multi-container local development
• Pushing images to container registry
• Optimizing image sizes

Procedure

Phase 1: Backend Dockerfile (Express on port 4000)

FROM node:20-alpine AS builder
WORKDIR /app
COPY package.json pnpm-lock.yaml ./
RUN corepack enable && pnpm install --frozen-lockfile
COPY . .

FROM node:20-alpine
WORKDIR /app
RUN corepack enable
COPY --from=builder /app/node_modules ./node_modules
COPY --from=builder /app/backend ./backend
COPY --from=builder /app/apps ./apps
COPY package.json ./
ENV NODE_ENV=production
EXPOSE 4000
CMD ["node", "backend/src/index.js"]

Important: Backend runs on port 4000, not 3000.

Phase 2: Frontend Dockerfile (Next.js on port 3000)

FROM node:20-alpine AS builder
WORKDIR /app
COPY package.json pnpm-lock.yaml ./
RUN corepack enable && pnpm install --frozen-lockfile
COPY . .
RUN cd frontend && pnpm build

FROM node:20-alpine
WORKDIR /app
COPY --from=builder /app/frontend/.next/standalone ./
COPY --from=builder /app/frontend/public ./public
EXPOSE 3000
CMD ["node", "server.js"]

Phase 3: Docker Compose

services:
  backend:
    build: { context: ., dockerfile: Dockerfile }
    ports: ["4000:4000"]
    environment:
      MONGODB_URI: mongodb://mongo:27017/Resource-Adda
      JWT_SECRET: ${JWT_SECRET}
    depends_on: [mongo]
  frontend:
    build: { context: ., dockerfile: Dockerfile.frontend }
    ports: ["3000:3000"]
    environment:
      NEXT_PUBLIC_API_BASE_URL: http://backend:4000
    depends_on: [backend]
  mongo:
    image: mongo:7
    ports: ["27017:27017"]
    volumes: ["mongo-data:/data/db"]
volumes:
  mongo-data:

Phase 4: .dockerignore

node_modules
.next
.git
.env
.env.local
coverage

Quick Reference

docker compose up --build         # Build and start all
docker compose logs -f backend    # View backend logs
docker compose down -v            # Stop and remove volumes
docker compose exec backend sh    # Shell into backend

Common Issues

Issue	Solution
Container crashes	Check logs: docker compose logs backend
DB connection refused	Ensure depends_on: [mongo]; wait for startup
Port conflict	Change ports in compose file
Image too large	Use Alpine base, multi-stage build, .dockerignore