Activate virtualenv INSIDE the my current bash (no subprocess) - bash

Question

I want to have a generic BASH script witch activates my virtual
environment inside a given folder.
The script should be able to be called from from any folder I have a virtual environment in.
If there is no virtual environment it should create one and install the pip requirements.
I can not run the activation inside my original BASH only as a subprocess (see --rcfile). Just source-ing it is not working!
Thats my current script:
#!/bin/bash -e
# BASH script to run virtual environment
# Show errors
set -x
DIR_CURRENT="$PWD"
DIR_VIRTUAL_ENV="$PWD/venv"
FILE_PYTHON="/usr/bin/python2.7"
FILE_REQUIREMENTS="requirements.txt"
FILE_VIRTUAL_ACTIVATE_BASH="$DIR_VIRTUAL_ENV/bin/activate"
# CD to current folder
cd ${DIR_CURRENT}
echo DIR: $(pwd)
# Create the virtual environment if not existing
if [ ! -d ${DIR_VIRTUAL_ENV} ]; then
virtualenv -p ${FILE_PYTHON} ${DIR_VIRTUAL_ENV}
chmod a+x ${FILE_VIRTUAL_ACTIVATE_BASH}
source ${FILE_VIRTUAL_ACTIVATE_BASH}
pip install -r ${FILE_REQUIREMENTS}
fi
/bin/bash --rcfile "$FILE_VIRTUAL_ACTIVATE_BASH"
# Disable errors
set +x
I use Mac OSX 10.10.5 and Python 2.7.
Sadly existing 1, 2, 3 questions couldn't answer my problem.

Answer 1

First, what you are trying to do has already been nicely solved by a project called virtualenvwrapper.
About your question: Use a function instead of a script. Place this into your bashrc for example:
function enter_venv(){
# BASH script to run virtual environment
# Show errors
set -x
DIR_CURRENT="$PWD"
DIR_VIRTUAL_ENV="$PWD/venv"
FILE_PYTHON="/usr/bin/python2.7"
FILE_REQUIREMENTS="requirements.txt"
FILE_VIRTUAL_ACTIVATE_BASH="$DIR_VIRTUAL_ENV/bin/activate"
# CD to current folder
cd ${DIR_CURRENT}
echo DIR: $(pwd)
# Create the virtual environment if not existing
if [ ! -d ${DIR_VIRTUAL_ENV} ]; then
virtualenv -p ${FILE_PYTHON} ${DIR_VIRTUAL_ENV}
chmod a+x ${FILE_VIRTUAL_ACTIVATE_BASH}
source ${FILE_VIRTUAL_ACTIVATE_BASH}
pip install -r ${FILE_REQUIREMENTS}
fi
/bin/bash --rcfile "$FILE_VIRTUAL_ACTIVATE_BASH"
# Disable errors
set +x
}
The you can call it like this:
enter_venv