One-shot Docker setup script (Ubuntu)

#!/bin/bash

set -e

echo "Updating system..."
sudo apt update && sudo apt upgrade -y

echo "Installing prerequisites..."
sudo apt install -y apt-transport-https ca-certificates curl software-properties-common

echo "Adding Docker GPG key..."
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

echo "? Adding Docker repository..."
sudo add-apt-repository \
   "deb [arch=$(dpkg --print-architecture)] https://download.docker.com/linux/ubuntu \
   $(lsb_release -cs) stable"

echo "Updating package index..."
sudo apt update

echo "Installing Docker..."
sudo apt install -y docker-ce docker-ce-cli containerd.io

echo "Starting Docker service..."
sudo systemctl start docker
sudo systemctl enable docker

echo "Adding current user to docker group..."
sudo usermod -aG docker $USER

echo "Verifying Docker installation..."
docker --version

echo "Done!"
echo "IMPORTANT: Log out and log back in (or run 'newgrp docker') to use Docker without sudo."