db.py 文件源码

def from_environment(cls) -> Optional['PostgresDemoDatabase']:
        host = os.environ.get("DEMO_POSTGRES_HOST")
        port = os.environ.get("DEMO_POSTGRES_PORT") or "5432"
        dbname = os.environ.get("DEMO_POSTGRES_DBNAME")
        user = os.environ.get("DEMO_POSTGRES_USER")
        password = os.environ.get("DEMO_POSTGRES_PASSWORD")

        if all([host, port, dbname, user, password]):
            try:
                logger.info("Initializing demo database connection using environment variables")
                return PostgresDemoDatabase(dbname=dbname, host=host, port=port, user=user, password=password)
            except psycopg2.Error:
                logger.exception("unable to connect to database, permalinks not enabled")
                return None
        else:
            logger.info("Relevant environment variables not found, so no demo database")
            return None