Core Concepts

Image: Lightweight, standalone, executable package containing code, runtime, system tools, and OS.
Container: Runnable instance of an image, representing a specific execution environment.
Volume: Persistent data storage mechanism, ensuring data durability and persistence even if containers are stopped or removed.
Network: Facilitates connectivity between Docker containers.

Basic Commands

docker build -t <image_name>: Build a Docker image.
docker images: View Docker images.
docker ps: View running containers.
docker ps -a: View all containers.
docker prune: Remove all idle containers.
docker rm <container_id>: Delete a container.
docker run -p <host_port>:<container_port> <image_name>: Run a container.
docker run -p <host_port>:<container_port> -v "$(pwd):/app" -v /app/node_modules <image_name>: Run a container with live code updates.

Dockerfile Example

FROM node:20-alpine

WORKDIR /app

COPY . .

CMD node hello.js

Docker Compose

Docker Compose simplifies multi-container Docker applications.
Define services in a YAML file (docker-compose.yaml).
Use docker compose up to start services defined in the docker-compose.yaml.
Use docker compose watch for development, syncing changes and rebuilding containers as necessary.

Docker Compose YAML Example

services:
  web:
    build:
      context: .
    ports:
      - 5173:5173
    volumes:
      - .:/app
      - /app/node_modules
    develop:
      watch:
        - path: ./frontend/package.json
          action: rebuild
        - path: ./frontend/package-lock.json
          action: rebuild
        - path: ./frontend
          target: /app
          action: sync

Docker Compose Watch Mode

Enables live development and testing.
Syncs changes, rebuilds, and restarts containers automatically.

docker compose watch