bootstrap a ruby project w/ bundler & rbenv

bootstrap.sh

#!/usr/bin/env bash
NOW=$(date +"%Y%m%d%H%M%S")
echo -n "[*] bootstrapping "
# Export CC to explicitly set the compiler used for cexts.
export CC=cc

function abspath {
  if [[ -d "$1" ]]; then
    pushd "$1" >/dev/null
    pwd
    popd >/dev/null
  elif [[ -e $1 ]]; then
    pushd "$(dirname "$1")" >/dev/null
    echo "$(pwd)/$(basename "$1")"
    popd >/dev/null
  else
    echo "$1" does not exist! >&2
    return 127
  fi
}

ABSPATH=$(abspath ".")
echo "${ABSPATH} (@${NOW}).. "

GEM_HOME=${ABSPATH}/vendor/gems/ruby/1.9.1
GEM_PATH=${ABSPATH}/vendor/gems/ruby/1.9.1
PATH=${ABSPATH}/bin:${ABSPATH}/vendor/gems/bin:${PATH}

# if rbenv?
USING_RBENV=$(rbenv version)
if [[ $? == 0 ]]; then
  echo "- Using rbenv: ${USING_RBENV}"
  RUBY_CMD_PREFIX='rbenv exec'

  # can run `which ruby` => grep for rbenv if rbenv exists `rbenv version` gives
  # output, no env setting if using default ruby in rbenv, otherwise
  # RBENV_VERSION is set
  if ! [[ -f .rbenv-vars ]]; then
    echo "- no .rbenv-vars, creating"
    cat <<- EOF >> .rbenv-vars
    GEM_HOME=${GEM_HOME}
    GEM_PATH=${GEM_PATH}
    PATH=${PATH}
EOF
  fi
fi

# clean out any old .bundles
if [[ -a ${ABSPATH}/.bundle ]]; then
  echo "- moving existing .bundle to .bundle.${NOW}"
  mv ${ABSPATH}/.bundle ${ABSPATH}/.bundle.${NOW}
  mkdir .bundle
fi

echo "- installing bundler"
${RUBY_CMD_PREFIX} gem install bundler

# Bundle install unless we're already up to date.
echo "- checking bundle"
if ! ${RUBY_CMD_PREFIX} bundle check > /dev/null 2>&1; then
  echo "- running bundle install"
  ${RUBY_CMD_PREFIX} bundle install --binstubs --path vendor/gems "$@"
else
  echo "- bundle ok"
fi