config.py

import os, base64, tempfile

def set_environment():
    b64 = os.getenv("GCP_CREDS_B64")
    key_bytes = base64.b64decode(b64)
    with tempfile.NamedTemporaryFile(delete=False, suffix=".json") as tmp:
        tmp.write(key_bytes)
        tmp_path = tmp.name

    os.environ["GOOGLE_APPLICATION_CREDENTIALS"] = tmp_path