heroku-buildpack-python/bin/steps/geo-libs

#!/usr/bin/env bash

# This script serves as the GDAL build step of the
# [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python)
# compiler.
#
# A [buildpack](https://devcenter.heroku.com/articles/buildpacks) is an
# adapter between a Python application and Heroku's runtime.
#
# This script is invoked by [`bin/compile`](/).

# The location of the pre-compiled cryptography binary.
VENDORED_GDAL="https://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/gdal.tar.gz"
VENDORED_GEOS="https://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/geos.tar.gz"
VENDORED_PROJ="https://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/proj.tar.gz"

PKG_CONFIG_PATH="/app/.heroku/vendor/lib/pkgconfig:$PKG_CONFIG_PATH"

# Syntax sugar.
# shellcheck source=bin/utils
source "$BIN_DIR/utils"

# If GDAL exists within requirements, use vendored gdal.
if [[ "$BUILD_WITH_GEO_LIBRARIES" ]]; then

  if [ ! -f ".heroku/vendor/bin/proj" ]; then
    echo "-----> Bootstrapping gdal, geos, proj."
    mkdir -p .heroku/vendor
    # Download and extract cryptography into target vendor directory.
    curl "$VENDORED_GDAL" -s | tar zxv -C .heroku/vendor &> /dev/null
    curl "$VENDORED_GEOS" -s | tar zxv -C .heroku/vendor &> /dev/null
    curl "$VENDORED_PROJ" -s | tar zxv -C .heroku/vendor &> /dev/null
  fi

  GDAL=$(pwd)/vendor
  export GDAL
fi