gruntwork-install

#!/bin/bash
#
# This script installs Gruntwork Script Modules. The main motivation in writing it is to make installing
# Gruntwork Script Modules feel as easy as installing a package using apt-get, brew, or yum.
#
# Note that if the user specifies neither --tag nor --branch, the latest tag is downloaded.
#

set -e

readonly MODULES_DIR="modules"
readonly MODULE_INSTALL_FILE_NAME="install.sh"

readonly DEFAULT_MODULES_DOWNLOAD_DIR="/tmp/gruntwork-script-modules"
readonly BIN_DIR="/usr/local/bin"

function print_usage {
  echo
  echo "Usage: gruntwork-install [OPTIONS]"
  echo
  echo "Download a Gruntwork Script Module and install it."
  echo
  echo "Required Arguments:"
  echo
  echo -e "  --repo\t\tThe repo to install from."
  echo -e "  --tag\t\t\tThe version of --repo to install. Follows the syntax described at https://github.com/gruntwork-io/fetch#tag-constraint-expressions."
  echo
  echo "Specify exactly one of:"
  echo
  echo -e "  --module-name\t\tThe name of a module to install. Can be any folder within the $MODULES_DIR directory of --repo."
  echo -e "  --binary-name\t\tThe name of a binary to install. Can be any file uploaded as a release asset in --repo."
  echo -e "  --binary-sha256-checksum\t\tThe SHA256 checksum of the binary specified by --binary-name. Should be exactly 64 characters."
  echo -e "  --binary-sha512-checksum\t\tThe SHA512 checksum of the binary specified by --binary-name. Should be exactly 128 characters."
  echo -e "  --binary-name\t\tThe name of a binary to install. Can be any file uploaded as a release asset in --repo."
  echo
  echo "Optional Arguments:"
  echo
  echo -e "  --module-param\tA key-value pair of the format key=value you wish to pass to the module as a parameter. May be used multiple times."
  echo -e "  --download-dir\tThe directory to which the module will be downloaded and from which it will be installed. Default: $DEFAULT_MODULES_DOWNLOAD_DIR"
  echo -e "  --branch\t\tDownload the latest commit from this branch in --repo. This is an alternative to --tag, used only for testing."
  echo -e "  --help\t\tShow this help text and exit."

  echo
  echo "Example:"
  echo
  echo "  gruntwork-install \\"
  echo "    --module-name 'vault-ssh-helper' \\"
  echo "    --repo 'https://github.com/gruntwork-io/script-modules' \\"
  echo "    --tag '~>0.0.3' \\"
  echo "    --module-param 'install-dir=/opt/vault-ssh-helper' \\"
  echo "    --module-param 'owner=ubuntu'"
  echo
}

function log {
  local readonly level="$1"
  local readonly message="$2"
  local readonly timestamp=$(date +"%Y-%m-%d %H:%M:%S")
  local readonly scriptname="$(basename "$0")"

  >&2 echo -e "${timestamp} [${level}] [$scriptname] ${message}"
}

function log_info {
  local readonly message="$1"
  log "INFO" "$message"
}

function log_warn {
  local readonly message="$1"
  log "WARN" "$message"
}

function log_error {
  local readonly message="$1"
  log "ERROR" "$message"
}

# Assert that a given binary is installed on this box
function assert_is_installed {
  local readonly name="$1"

  if [[ ! $(command -v ${name}) ]]; then
    log_error "The binary '$name' is required by this script but is not installed or in the system's PATH."
    exit 1
  fi
}

function assert_not_empty {
  local readonly arg_name="$1"
  local readonly arg_value="$2"

  if [[ -z "$arg_value" ]]; then
    log_error "The value for '$arg_name' cannot be empty"
    print_usage
    exit 1
  fi
}

function assert_env_var_not_empty {
  local readonly var_name="$1"
  local readonly var_value="${!var_name}"

  if [[ -z "$var_value" ]]; then
    log_error "Required environment variable $var_name not set."
    exit 1
  fi
}

# Download the files of the given Script Module using fetch (https://github.com/gruntwork-io/fetch)
function fetch_script_module {
  local readonly module_name="$1"
  local readonly tag="$2"
  local readonly branch="$3"
  local readonly download_dir="$4"
  local readonly repo="$5"

  # We want to make sure that all folders down to $download_path/$module_name exists, but that $download_path/$module_name itself is empty.
  mkdir -p "$download_dir/$module_name/"
  rm -Rf "$download_dir/$module_name/"

  # Note that fetch can safely handle blank arguments for --tag or --branch
  # If both --tag and --branch are specified, --branch will be used
  log_info "Downloading module $module_name from $repo"
  fetch --repo="$repo" --tag="$tag" --branch="$branch" --source-path="/modules/$module_name" "$download_dir/$module_name"
}

# Download a binary asset from a GitHub release using fetch (https://github.com/gruntwork-io/fetch)
function fetch_binary {
  local readonly binary_name="$1"
  local readonly tag="$2"
  local readonly download_dir="$3"
  local readonly repo="$4"
  local readonly sha256_checksum="$5"
  local readonly sha512_checksum="$6"

  local binary_name_full=""
  binary_name_full=$(determine_binary_name "$binary_name")

  local readonly full_download_path="$download_dir/$binary_name_full"
  local readonly full_dest_path="$BIN_DIR/$binary_name"

  # We want to make sure that all folders down to $download_path exist, but that $download_path/$binary_name_full does not
  mkdir -p "$download_dir"
  rm -f "$download_dir/$binary_name_full"

  if [[ ! -z "$sha256_checksum" ]]; then
    fetch --repo="$repo" --tag="$tag" --release-asset="$binary_name_full" "$download_dir" --release-asset-checksum-algo "sha256" --release-asset-checksum "$sha256_checksum"
   elif [[ ! -z "$sha512_checksum" ]]; then
    fetch --repo="$repo" --tag="$tag" --release-asset="$binary_name_full" "$download_dir" --release-asset-checksum-algo "sha512" --release-asset-checksum "$sha512_checksum"
  else
    fetch --repo="$repo" --tag="$tag" --release-asset="$binary_name_full" "$download_dir"
  fi

  log_info "Moving $full_download_path to $full_dest_path and setting execute permissions"
  sudo mv "$full_download_path" "$full_dest_path"
  sudo chmod u+x "$full_dest_path"
}

# Validate that at least one file was downloaded from the module; otherwise throw an error.
function validate_module {
  local readonly module_name="$1"
  local readonly download_dir="$2"
  local readonly tag="$3"
  local readonly branch="$4"
  local reaodnly repo="$5"

  if [[ ! -e "$download_dir/$module_name" ]]; then
    log_error "No files were downloaded. Are you sure \"$module_name\" is a valid Script Module in $repo (tag = $tag, branch = $branch)?"
    exit 1
  fi
}

# http://stackoverflow.com/a/2264537/483528
function to_lower_case {
  tr '[:upper:]' '[:lower:]'
}

function get_os_name {
  uname | to_lower_case
}

function get_os_arch {
  uname -m
}

function string_contains {
  local readonly str="$1"
  local readonly contains="$2"

  [[ "$str" == *"$contains"* ]]
}

function get_os_arch_gox_format {
  local readonly arch=$(get_os_arch)

  if $(string_contains "$arch" "64"); then
    echo "amd64"
  elif $(string_contains "$arch" "386"); then
    echo "386"
  elif $(string_contains "$arch" "arm"); then
    echo "arm"
  fi
}

# We release binaries with the name following the format <NAME>_<OS>_<ARCH> (e.g. foo_linux_amd64). Given the NAME of
# a binary, this function adds the proper OS and ARCH to it for the current OS.
function determine_binary_name {
  local readonly binary_name="$1"
  local readonly os_name=$(get_os_name)
  local readonly os_arch=$(get_os_arch_gox_format)
  echo "${binary_name}_${os_name}_${os_arch}"
}

# Take in a key-value pair of the format key=value and convert it to the format that Gruntwork bash scripts expect:
# --key value
function convert_module_params_format {
  local readonly key_value_pair="$1"
  local readonly key="${key_value_pair%%=*}"
  local readonly val="${key_value_pair#*=}"
  echo "--${key} \"${val}\""
}

function run_module {
  local readonly module_name="$1"
  local readonly download_dir="$2"
  shift 2
  local readonly module_params=($@)
  local readonly install_script_path="${download_dir}/${module_name}/${MODULE_INSTALL_FILE_NAME}"

  log_info "Executing $install_script_path ${module_params[@]}"
  chmod u+x "$install_script_path"
  eval "$install_script_path ${module_params[@]}"
}

function install_script_module {
  local tag=""
  local branch=""
  local module_name=""
  local binary_name=""
  local binary_sha256_checksum=""
  local binary_sha512_checksum=""
  local repo=""
  local download_dir="$DEFAULT_MODULES_DOWNLOAD_DIR"
  local module_params=()

  while [[ $# > 0 ]]; do
    local key="$1"

    case "$key" in
      --tag)
        tag="$2"
        shift
        ;;
      --branch)
        branch="$2"
        shift
        ;;
      --module-name)
        module_name="$2"
        shift
        ;;
      --binary-name)
        binary_name="$2"
        shift
        ;;
      --binary-sha256-checksum)
        binary_sha256_checksum="$2"
        shift
        ;;
      --binary-sha512-checksum)
        binary_sha512_checksum="$2"
        shift
        ;;
      --repo)
        repo="$2"
        shift
        ;;
      --module-param)
        local readonly param=$(convert_module_params_format "$2")
        module_params+=("$param")
        shift
        ;;
      --download-dir)
        download_dir="$2"
        shift
        ;;
      --help)
        print_usage
        exit
        ;;
      *)
        echo "ERROR: Unrecognized option: $key"
        print_usage
        exit 1
        ;;
    esac

    shift
  done

  assert_is_installed fetch
  assert_env_var_not_empty "GITHUB_OAUTH_TOKEN"
  assert_not_empty "--repo" "$repo"

  if [[ ( -z "$module_name" && -z "$binary_name" ) || ( ! -z "$module_name" && ! -z "$binary_name" ) ]]; then
    log_error "You must specify exactly one of --module-name or --binary-name."
    exit 1
  fi

  if [[ ! -z "$binary_name" && -z "$tag" ]]; then
    log_error "--binary-name can only be used if you specify a release via --tag."
    exit 1
  fi

  if [[ ! -z "$binary_sha256_checksum" && ! -z "$binary_sha512_checksum" ]]; then
    log_error "You must specify at most one of --binary-sha256-checksum and --binary-sha512-checksum"
    exit 1
  fi

  if [[ ! -z "$module_name" ]]; then
    log_info "Installing from $module_name..."
    fetch_script_module "$module_name" "$tag" "$branch" "$download_dir" "$repo"
    validate_module "$module_name" "$download_dir" "$tag" "$branch" "$repo"
    run_module "$module_name" "$download_dir" "${module_params[@]}"
  else
    log_info "Installing $binary_name..."
    fetch_binary "$binary_name" "$tag" "$download_dir" "$repo" "$binary_sha256_checksum" "$binary_sha512_checksum"
  fi

  log_info "Success!"
}

install_script_module "$@"