$devvkit learn --librarie docker-guide

Docker Guide

[containers][devops][deployment][cli]

Universal

Install

# macOS / Windows
# Download from https://docker.com/products/docker-desktop

# Linux
curl -fsSL https://get.docker.com | sh

Docker changed how we ship software. Instead of "it works on my machine," you get a reproducible environment defined in a Dockerfile.

A container shares the host kernel, starting in milliseconds and using far fewer resources than a VM.

Images

Pull an image· Download a pre-built image.

docker pull node:20-slim

List images· Show downloaded images.

docker images

Build an image· Build from a Dockerfile.

docker build -t my-app:latest .

Remove an image· Delete an image.

docker rmi node:20-slim

Containers

Run a container· Start a container from an image.

docker run -d -p 3000:3000 --name my-app my-app:latest

Run interactively· Start with a shell for debugging.

docker run -it node:20-slim /bin/bash

List containers· Show running containers.

docker ps

Stop a container· Gracefully stop.

docker stop my-app

View logs· Follow logs from a container.

docker logs -f my-app

Exec in container· Run command in running container.

docker exec -it my-app /bin/bash

Dockerfile

Dockerfile· Multi-stage build for Node.js.

FROM node:20-slim AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build

FROM node:20-slim
WORKDIR /app
COPY --from=builder /app/dist ./dist
EXPOSE 3000
CMD ["node", "dist/index.js"]

Docker Compose

Docker Compose· Define multi-container app.

version: "3.9"
services:
  app:
    build: .
    ports:
      - "3000:3000"
    depends_on:
      - db
  db:
    image: postgres:16-alpine

Compose up· Launch all services.

docker compose up -d

Cleanup

System prune· Remove all unused resources.

docker system prune -a --volumes