🐳 Docker & Containerization

🔄 A platform to develop, ship, and run applications in containers, making them portable and consistent across environments.
🔄 Containers: Running instances of Docker images. Think of them as lightweight, isolated environments.
🔄 Dockerfile: A script with instructions to build Docker images (e.g., from Ubuntu, install packages, copy code, etc.).
🔄 Docker Compose: A tool to define and manage multi-container apps using docker-compose.yml.
🔄 Networking: Docker provides isolated virtual networks; containers can communicate using service names.

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✅ Common Docker Commands

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

# Build image from Dockerfile
docker build -t myapp .

# List running containers
docker ps

# Start/stop containers
docker start <id> && docker stop <id>

# Remove container/image
docker rm <id> && docker rmi <image>

🐳 NextCloud powered by Docker

1. Install Server - I am using Hyper-V and Ubuntu Server LTS
   
2. Install updates
   
3. Install Docker and set running docker without sudo (avoiding using sudo with every docker command)
   sudo usermod -aG docker $USER
   The docker group is created automatically during the Docker installation.
   
4. Install Docker Compose sudo apt install -y docker-compose
   
5. mkdir nextcloud-docker
   
6. cd nextcloud-docker
   
7. Create a docker-compose.yml file:

version: '3'

services:
  db:
    image: mariadb:10.6
    restart: always
    command: --transaction-isolation=READ-COMMITTED --binlog-format=ROW
    volumes:
      - db:/var/lib/mysql
    environment:
      - MYSQL_ROOT_PASSWORD=secret
      - MYSQL_PASSWORD=nextcloudpass
      - MYSQL_DATABASE=nextcloud
      - MYSQL_USER=nextclouduser

  app:
    image: nextcloud
    ports:
      - 8080:80
    links:
      - db
    volumes:
      - nextcloud:/var/www/html
    restart: always
    environment:
      - MYSQL_PASSWORD=nextcloudpass
      - MYSQL_DATABASE=nextcloud
      - MYSQL_USER=nextclouduser
      - MYSQL_HOST=db

volumes:
  db:
  nextcloud:

8. docker-compose up -d
   
9. http://your-server-ip:8080