#!/usr/bin/env bash
# Run this ONCE on a fresh Ubuntu host to install Docker + Compose v2 and
# add the current user to the `docker` group so subsequent commands don't
# need sudo.
#
# Requires sudo. Idempotent — safe to re-run.
#
# Usage:
#   ssh tudisco@host 'bash -s' < install-docker.sh
# or:
#   scp install-docker.sh tudisco@host:~/
#   ssh tudisco@host 'bash ~/install-docker.sh'

set -euo pipefail

echo "==> Updating apt"
sudo apt-get update -y

echo "==> Installing prerequisites"
sudo apt-get install -y --no-install-recommends \
    ca-certificates curl gnupg

echo "==> Adding Docker's official GPG key"
sudo install -m 0755 -d /etc/apt/keyrings
if [[ ! -f /etc/apt/keyrings/docker.gpg ]]; then
  curl -fsSL https://download.docker.com/linux/ubuntu/gpg \
    | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
  sudo chmod a+r /etc/apt/keyrings/docker.gpg
fi

echo "==> Adding Docker apt repo"
. /etc/os-release
echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] \
https://download.docker.com/linux/ubuntu ${VERSION_CODENAME} stable" \
  | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

echo "==> Installing Docker Engine + Compose plugin"
sudo apt-get update -y
sudo apt-get install -y \
    docker-ce docker-ce-cli containerd.io \
    docker-buildx-plugin docker-compose-plugin

echo "==> Adding $USER to docker group"
sudo usermod -aG docker "$USER"

echo "==> Enabling + starting Docker"
sudo systemctl enable --now docker

echo
echo "==> Versions:"
docker --version
docker compose version

echo
echo "✓ Docker installed."
echo "  IMPORTANT: log out and back in (or run 'newgrp docker') for the"
echo "  group change to take effect; otherwise 'docker' commands need sudo."