Detecting new instance creation at runtime on Google App Engine

gistfile1.py

current_instance_id = None

def is_loading_request_wsgi_middleware(app):
    import logging
    
    def is_loading_request_wsgi_middleware_wrapper(environ, start_response):
        global current_instance_id

        if current_instance_id != environ.get('INSTANCE_ID'):
            current_instance_id = environ.get('INSTANCE_ID')
            logging.info("new instance loaded %s", current_instance_id)

        return app(environ, start_response)

    return is_loading_request_wsgi_middleware_wrapper

 
def webapp_add_wsgi_middleware(app):
    app = is_loading_request_wsgi_middleware(app)
    return app