1. Installing Docker

🐧 Linux (Ubuntu/Debian)

# Update package index
sudo apt update

# Install prerequisites
sudo apt install apt-transport-https ca-certificates curl software-properties-common

# Add Docker GPG key
curl -fsSL <https://download.docker.com/linux/ubuntu/gpg> | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

# Add repository
echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] <https://download.docker.com/linux/ubuntu> $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

# Install Docker
sudo apt update
sudo apt install docker-ce docker-ce-cli containerd.io

# Verify
sudo docker --version

✅ Repository Confirmation: As per your knowledge base, https://download.docker.com/linux/ubuntu/ contains valid dists/ and gpg files.

🐧 Linux (RHEL/CentOS/Fedora)

# RHEL/CentOS 8+
sudo dnf install dnf-plugins-core
sudo dnf config-manager --add-repo <https://download.docker.com/linux/centos/docker-ce.repo>
sudo dnf install docker-ce docker-ce-cli containerd.io
sudo systemctl enable --now docker

🍏 macOS

1. Download Docker Desktop for Mac from docker.com
2. Install the .dmg file
3. Launch Docker Desktop from Applications
4. Verify: docker --version

🪟 Windows

1. Prerequisites: Windows 10/11 Pro/Enterprise (WSL2 enabled)
2. Download Docker Desktop for Windows from docker.com
3. Run installer as Administrator
4. Enable WSL2 backend during setup
5. Verify: docker --version

2. Basic Docker Commands