Docker | Notion

Docker Core Concepts

Term	Description
Image	A read-only template created by `docker build`, containing everything needed to run an application.
Container	A runnable instance of an image, representing the actual running application process.
Volume	A mechanism for persisting and sharing data between containers and the host filesystem.
Dockerfile	A “recipe” that defines how to build your image, specifying base image, dependencies, build steps, and startup command.
.dockerignore	A file that lists patterns for files and directories to exclude from the build context.
docker-compose	A tool for defining and running multi-container Docker applications via a `docker-compose.yml` file.

Common Commands Quick Reference

# Build an image from the current directory’s Dockerfile
docker build -t my-next-app .

# Run a container (map host port 3000 to container port 3000)
docker run -p 3000:3000 my-next-app

# List all containers (running and stopped)
docker ps -a

# Start a stopped container
docker start <container-name-or-id>

# Stop a running container
docker stop <container-name-or-id>

# List all images on your system
docker images

# Remove a container
docker rm <container-id>

# Remove an image
docker rmi <image-id>

# Remove unused data (dangling images, stopped containers, unused networks)
docker system prune

Dockerfile

FROM node:22-alpine AS base

# Stage 1: Install dependencies
FROM base AS deps
WORKDIR /app

COPY package*.json ./
RUN npm install

# Stage 2: Build the application
FROM base AS builder
WORKDIR /app

COPY --from=deps /app/node_modules ./node_modules
COPY . .
RUN npm run build

# Stage 3: Run the application
FROM base AS runner
WORKDIR /app

ENV NODE_ENV=production
ENV PORT=3000
ENV HOSTNAME=0.0.0.0

COPY --from=builder /app/.next/standalone ./
COPY --from=builder /app/.next/static ./.next/static
COPY --from=builder /app/public ./public

EXPOSE 3000
CMD ["node", "server.js"]

.dockerignore

# Git
.git
.gitignore

# Dependencies
node_modules/

# Local env files
.env
.env.*.local

# Next.js
.next/
out/
dist/

# TypeScript
next-env.d.ts

# IDE
.vscode/
.idea/

# OS metadata
.DS_Store
Thumbs.db

# Logs
logs/
*.log

# Docker files
Dockerfile*
.dockerignore

# Documentation
README*.md
LICENSE
CONTRIBUTING.md