virtualenvwrapper postactivate and predeactivate scripts to export all a .env file's declarations (foreman style) into your bash environment on activate, then clean them up on deactivate. Also tells npm and rvm to install packages directly into the active virtualenv. Useful for Heroku-hosted project development.

postactivate-env-setup

#!/bin/bash
# This hook should be run after every virtualenv is activated.
# See `predeactivate-env-cleanup` to configure automatic clean-up.
#
# INSTALLATION
#   Save the latest version of this file into your virtualenvwrapper 
#   hook directory (e.g., ~/.virtualenvs):
#     $ echo "$(curl -fsSl https://gist.githubusercontent.com/kbambz/10002069/raw/postactivate-env-setup)" > $VIRTUALENVWRAPPER_HOOK_DIR/postactivate-env-setup
#
#   Then tell postactivate to invoke the script when it runs:
#     $ chmod +x $VIRTUALENVWRAPPER_HOOK_DIR/postactivate-env-setup
#     $ echo "[ -f \$VIRTUALENVWRAPPER_HOOK_DIR/postactivate-env-setup ] && source \$VIRTUALENVWRAPPER_HOOK_DIR/postactivate-env-setup" >> $VIRTUALENVWRAPPER_HOOK_DIR/postactivate
#
# @author Kate Bambino (kbambz)

echo ""
echo -e "\033[1;32mActivating virtualenv \033[0;35m$(basename $VIRTUAL_ENV)\033[0m"

# Check if a project is associated with this virtual environment
if [ -e "$VIRTUAL_ENV/$VIRTUALENVWRAPPER_PROJECT_FILENAME" ]; then
   VIRTUAL_ENV_PROJECT_PATH=`cat "$VIRTUAL_ENV/$VIRTUALENVWRAPPER_PROJECT_FILENAME"`
   echo -e "  \033[1;32m@ \033[0;35m$VIRTUAL_ENV_PROJECT_PATH\033[0m"
   echo ""

   # Read project .env file declarations into bash environment
   if [ -e "$VIRTUAL_ENV_PROJECT_PATH/.env" ]; then
       echo -e "\033[1;37mReading project's .env file declarations into bash environment...\033[0m"
       while read line; do
           [ -z "$line" ] && continue
           [ -z "${line%%#*}" ] && continue
           export ${line%%=*}="${line#*=}"
           echo "  > ${line%%=*}"
       done < "$VIRTUAL_ENV_PROJECT_PATH/.env"
   else
       echo -e "\033[1;33mWARNING:\033[0m Project root does not contain an .env file."
   fi
else
   echo -e "\033[1;33mWARNING:\033[0m There is no project directory associated with this virtualenv. To set one, cd into the project root and run \`setvirtualenvproject \$VIRTUAL_ENV \$(pwd) && workon \$(basename \$VIRTUAL_ENV)'"
fi
echo ""


# Make it so npm install -g <package> and rvm install <package>
# install directly into the active virtual environment

# Save existing values for cleanup in predeactivate
if [[ -n $GEM_HOME ]]; then
   export OLD_GEM_HOME=$GEM_HOME
fi
if [[ -n $GEM_PATH ]]; then
   export OLD_GEM_PATH=$GEM_PATH
fi
if [[ -n $npm_config_prefix ]]; then
   export OLD_npm_config_prefix=$npm_config_prefix
fi

export GEM_HOME="$VIRTUAL_ENV/lib/gems"
export GEM_PATH=""
PATH="$GEM_HOME/bin:$PATH"
export npm_config_prefix=$VIRTUAL_ENV
export PATH

predeactivate-env-cleanup

#!/bin/bash
# This hook should be run before every virtualenv is deactivated.
# It was designed to clean up any bash environment modifications
# made by postactivate hook `postactivate-env-setup`.
#
# INSTALLATION
#   Save the latest version of this file into your virtualenvwrapper 
#   hook directory (e.g., ~/.virtualenvs):
#     $ echo "$(curl -fsSl https://gist.githubusercontent.com/kbambz/10002069/raw/predeactivate-env-cleanup)" > $VIRTUALENVWRAPPER_HOOK_DIR/predeactivate-env-cleanup
#
#  Then tell predeactivate to invoke the script when it runs:
#     $ chmod +x $VIRTUALENVWRAPPER_HOOK_DIR/predeactivate-env-cleanup
#     $ echo "[ -f \$VIRTUALENVWRAPPER_HOOK_DIR/predeactivate-env-cleanup ] && source \$VIRTUALENVWRAPPER_HOOK_DIR/predeactivate-env-cleanup" >> $VIRTUALENVWRAPPER_HOOK_DIR/predeactivate
#
# @author Kate Bambino (kbambz)

# Check if a project is associated with this virtual environment
if [ -e "$VIRTUAL_ENV/$VIRTUALENVWRAPPER_PROJECT_FILENAME" ]; then
   VIRTUAL_ENV_PROJECT_PATH=`cat "$VIRTUAL_ENV/$VIRTUALENVWRAPPER_PROJECT_FILENAME"`

   if [ -e "$VIRTUAL_ENV_PROJECT_PATH/.env" ]; then
       echo -e "\033[1;37mCleaning up .env file associated bash assignments...\033[0m"

       # Clear .env file declarations from your bash environment
       while read line; do
           [ -z "$line" ] && continue
           [ -z "${line%%#*}" ] && continue
           if [[ -n ${line%%=*} ]]; then
               unset ${line%%=*}
               echo "  > ${line%%=*}"
           fi
       done < "$VIRTUAL_ENV_PROJECT_PATH/.env"
   fi
fi


# Make it so npm install -g <package> and rvm install <package>
# install to wherever they were set up to before this virtualenv
# was activated
if [[ -n $OLD_GEM_HOME ]]; then
   export GEM_HOME=$OLD_GEM_HOME
   unset OLD_GEM_HOME
else
   unset GEM_HOME
fi
if [[ -n $OLD_GEM_PATH ]]; then
   export GEM_PATH=$OLD_GEM_PATH
   unset OLD_GEM_PATH
else
   unset GEM_PATH
fi
if [[ -n $OLD_npm_config_prefix ]]; then
   export npm_config_prefix=$OLD_npm_config_prefix
   unset OLD_npm_config_prefix
else
   unset npm_config_prefix
fi

To fetch and install both scripts globally:

echo "$(curl -fsSl https://gist.githubusercontent.com/kbambz/10002069/raw/postactivate-env-setup)" > $VIRTUALENVWRAPPER_HOOK_DIR/postactivate-env-setup
echo "$(curl -fsSl https://gist.githubusercontent.com/kbambz/10002069/raw/predeactivate-env-cleanup)" > $VIRTUALENVWRAPPER_HOOK_DIR/predeactivate-env-cleanup
chmod +x $VIRTUALENVWRAPPER_HOOK_DIR/postactivate-env-setup
chmod +x $VIRTUALENVWRAPPER_HOOK_DIR/predeactivate-env-cleanup
echo "[ -f \$VIRTUALENVWRAPPER_HOOK_DIR/postactivate-env-setup ] && source \$VIRTUALENVWRAPPER_HOOK_DIR/postactivate-env-setup" >> $VIRTUALENVWRAPPER_HOOK_DIR/postactivate
echo "[ -f \$VIRTUALENVWRAPPER_HOOK_DIR/predeactivate-env-cleanup ] && source \$VIRTUALENVWRAPPER_HOOK_DIR/predeactivate-env-cleanup" >> $VIRTUALENVWRAPPER_HOOK_DIR/predeactivate

If you'd rather the scripts only run for specific projects/virtualenvs, install them into each virtualenv's bin directory instead. That is, from an activate virtualenv, do:

echo "$(curl -fsSl https://gist.githubusercontent.com/kbambz/10002069/raw/postactivate-env-setup)" > $VIRTUAL_ENV/$VIRTUALENVWRAPPER_ENV_BIN_DIR/postactivate-env-setup
echo "$(curl -fsSl https://gist.githubusercontent.com/kbambz/10002069/raw/predeactivate-env-cleanup)" > $VIRTUAL_ENV/$VIRTUALENVWRAPPER_ENV_BIN_DIR/predeactivate-env-cleanup
chmod +x $VIRTUAL_ENV/$VIRTUALENVWRAPPER_ENV_BIN_DIR/postactivate-env-setup
chmod +x $VIRTUAL_ENV/$VIRTUALENVWRAPPER_ENV_BIN_DIR/predeactivate-env-cleanup
grep -q "/postactivate-env-setup" "$VIRTUAL_ENV/$VIRTUALENVWRAPPER_ENV_BIN_DIR/postactivate" && echo "[ -f \$VIRTUAL_ENV/\$VIRTUALENVWRAPPER_ENV_BIN_DIR/postactivate-env-setup ] && source \$VIRTUAL_ENV/\$VIRTUALENVWRAPPER_ENV_BIN_DIR/postactivate-env-setup" >> $VIRTUAL_ENV/$VIRTUALENVWRAPPER_ENV_BIN_DIR/postactivate
grep -q "/predeactivate-env-cleanup" "$VIRTUAL_ENV/$VIRTUALENVWRAPPER_ENV_BIN_DIR/predeactivate" && echo "[ -f \$VIRTUAL_ENV/\$VIRTUALENVWRAPPER_ENV_BIN_DIR/predeactivate-env-cleanup ] && source \$VIRTUAL_ENV/\$VIRTUALENVWRAPPER_ENV_BIN_DIR/predeactivate-env-cleanup" >> $VIRTUAL_ENV/$VIRTUALENVWRAPPER_ENV_BIN_DIR/predeactivate

Navigate to a project's root directory and run workon <some-venv> to verify installation, noting you may need to deactivate your active virtualenv first.

If you ever want to disable the scripts, either remove postactivate-env-setup and predeactivate-env-cleanup from $VIRTUALENVWRAPPER_HOOK_DIR or comment out the lines referencing them from your postactivate and predeactivate scripts.