ansible with virtualenv bootstrap script

bootstrap-ansible.sh

#!/bin/bash

# exit on error, undeclared variables and pipe failures
set -e -u -o pipefail

# ansible is made for python 2.7+
# TODO: check version(s) and provide better errors if anything fails

# install virtualenv if it's not installed yet
which -s virtualenv || (sudo easy_install pip && sudo pip install virtualenv)

OLD_DIR=`pwd`
DIR=$(cd `dirname "$0"`; pwd)

cd "$DIR"
# create a lib folder
test -d lib || mkdir lib
# create virtualenv if it does not exist already
test -d lib/virtualenv || virtualenv lib/virtualenv
# activate virtualenv; activate uses undeclared variables, so use set +u
set +u;. lib/virtualenv/bin/activate;set -u
# make sure ansible is installed
{ pip show ansible | grep ansible &> /dev/null; } || pip install ansible

# print a message on how to use the virtualenv
cat <<MESSAGE
activate the virtualenv with
  . lib/virtualenv/bin/activate
MESSAGE
# and from where to use it if not already there
test "$DIR" != "$OLD_DIR" && echo after changing to the project directory "$DIR"

# change to previous directory to avoid surprises
cd "$OLD_DIR"