Docker - Containers¶

Introduction to Docker¶

Docker is a container platform that allows packaging applications and their dependencies in lightweight and portable containers. This facilitates development, deployment and scaling of applications.

🚀 Start with Docker in 10 minutes¶

New to Docker? Start here:

Official tutorial: Get started - Your first container in minutes
Play with Docker - Free online interactive environment
Docker Cheat Sheet - Essential commands

Fundamental concepts¶

Containers¶

Containers are isolated environments that contain everything needed to run an application.

Images¶

Images are read-only templates used to create containers.

Dockerfile¶

A Dockerfile is a script containing instructions to build an image.

# Example Dockerfile
FROM ubuntu:20.04
RUN apt-get update && apt-get install -y nginx
EXPOSE 80
CMD ["nginx", "-g", "daemon off;"]

Basic commands¶

Image management¶

# Build an image
docker build -t my-application .

# List images
docker images

# Remove an image
docker rmi my-application

Container management¶

# Run a container
docker run -d -p 8080:80 my-application

# List containers
docker ps

# Stop a container
docker stop <container_id>

# Remove a container
docker rm <container_id>

Docker Compose¶

Docker Compose allows defining and running multi-container applications.

# docker-compose.yml
version: '3.8'
services:
  web:
    build: .
    ports:
      - "8080:80"
  db:
    image: postgres:13
    environment:
      POSTGRES_DB: myapp
      POSTGRES_USER: user
      POSTGRES_PASSWORD: password

Use cases¶

Local development
Application deployment
Microservices
CI/CD pipelines

Next steps¶

In the following sections we will explore:

Image optimization
Docker networks
Volumes and persistence
Container security
Orchestration with Kubernetes