amazon-linux-docker

#!/usr/bin/env bash

# Install docker with docker-compose optionally on Amazon Linux 2
# Copyright 2021 asonnleitner

# -e : exit immediately if a command exits with a non-zero status
# -u : treat unset variables as an error when substituting
# -o pipefail : pipe commands to fd 3 in case a command in a pipe fails
set -euo pipefail

# Stdout logging utility function
# Usage:
# logger <level> <message> <message>
function logger() {
  local levels=("success" "trace" "debug" "info" "warn" "error" "fatal")
  local level="$1"
  local message
  local pretty_message

  # If the first argument is a valid log level, use it. and shift the rest of the arguments
  # Otherwise, use the default log level (info) and pass the first argument as the message
  if [[ "${levels[*]}" =~ ${level} ]]; then
    shift
  else
    level="info"
  fi

  message="$*"

  # If the message is empty, don't print anything
  if [[ -z "${message}" ]]; then
    return
  fi

  pretty_message="$(date +"%Y-%m-%d %H:%M:%S") [${level^^}]: ${message}"

  case "$level" in
  success)
    echo -e "\e[92m$pretty_message\e[0m"
    ;;
  trace)
    echo -e "\e[97m$pretty_message\e[0m"
    ;;
  debug)
    echo -e "\e[96m$pretty_message\e[0m"
    ;;
  info)
    echo -e "\e[34m$pretty_message\e[0m"
    ;;
  warn)
    echo -e "\e[93m$pretty_message\e[0m"
    ;;
  error)
    echo -e "\e[91m$pretty_message\e[0m"
    ;;
  fatal)
    echo -e "\e[91m$pretty_message\e[0m"
    exit 1
    ;;
  *) ;;
  esac
}

# Check if user is root $(id -u)
if [[ "$(id -u)" != "0" ]]; then
  logger "fatal" "This script must be run as root"
  exit 1
fi

# Check if running on Amazon Linux 2
function valid_distribution() {
  local amazon_linux_id="amzn"
  local amazon_linux_version="2"
  local error_message="This script is for Amazon Linux 2 only"

  if [ -f /etc/os-release ]; then
    . /etc/os-release
    if [[ "${ID}" = "${amazon_linux_id}" ]] && [[ "${VERSION_ID}" = "${amazon_linux_version}" ]]; then
      logger "trace" "Running on Amazon Linux 2"
      return
    else
      logger "fatal" "${error_message}"
    fi
  else
    logger "fatal" "${error_message}"
  fi
}

# Check if docker command is available
function docker_installed() {
  if [ -x "$(command -v docker)" ]; then
    logger "info" "Docker is already installed"
    exit 0
  else
    logger "trace" "Docker is not installed"
    return
  fi
}

# Install docker-compose
function install_docker_compose() {
  logger "info" "Installing docker-compose"
  curl -L "https://github.com/docker/compose/releases/latest/download/docker-compose-$(uname -s)-$(uname -m)" \
    -o /usr/local/bin/docker-compose

  # Make docker-compose executable
  chmod +x /usr/local/bin/docker-compose
}

function main() {
  # Check if running on Amazon Linux 2
  valid_distribution

  # Check if docker is installed
  docker_installed

  # Update system
  logger "info" "Updating system"
  yum update -y

  # Provide docker repository
  logger "info" "Providing docker repository"
  amazon-linux-extras install docker -y

  # Install docker
  logger "info" "Installing docker"
  yum install -y docker

  # Start docker
  logger "info" "Starting docker"
  systemctl enable docker --now

  # Add user to docker group
  logger "info" "Adding user to docker group"
  usermod -aG docker "${USER}"

  # Ask user if they want to install docker-compose
  read -rp "Do you want to install docker-compose? [y/n] " REPLY
  case "${REPLY}" in
  y | Y | yes | Yes | YES)
    install_docker_compose
    ;;
  *) ;;
  esac

  # Ask user if they want to reboot now
  read -rp "Do you want to reboot now? [y/n] " REPLY
  case "${REPLY}" in
  y | Y | yes | Yes | YES)
    reboot
    ;;
  *) ;;
  esac
}

#main "$@"
main