Yandex database

import os
import ydb
import ydb.iam
import logging
from time import sleep

# Set up logging for better debugging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

def get_credentials():
    """
    Retrieve credentials from environment variables or secret management system.
    This avoids hardcoding sensitive information.
    """
    try:
        credentials_path = os.getenv('YDB_CREDENTIALS_PATH')  # Store the path in an environment variable
        if not credentials_path:
            raise ValueError("YDB_CREDENTIALS_PATH environment variable not set.")
        return ydb.iam.ServiceAccountCredentials.from_file(credentials_path)
    except Exception as e:
        logger.error(f"Error retrieving credentials: {e}")
        raise

def execute_query(session):
    """
    Executes a simple query to check the connection and ensure the database is responsive.
    """
    try:
        result = session.transaction().execute(
            "SELECT 1 AS cnt;",
            commit_tx=True,
            settings=ydb.BaseRequestSettings().with_timeout(3).with_operation_timeout(2),
        )
        return result
    except ydb.Error as e:
        logger.error(f"YDB error executing query: {e}")
        raise

def retry_operation(func, session, retries=3, delay=2):
    """
    Retry logic for executing database operations in case of transient failures.
    """
    for attempt in range(retries):
        try:
            return func(session)
        except Exception as e:
            logger.warning(f"Attempt {attempt + 1} failed: {e}")
            if attempt < retries - 1:
                sleep(delay)  # Exponential backoff can be added here
            else:
                logger.error("Max retries reached. Operation failed.")
                raise

def initialize_driver():
    """
    Initializes the YDB driver with secure credentials and configuration.
    """
    try:
        driver = ydb.Driver(
            endpoint=os.getenv('YDB_ENDPOINT', 'grpcs://ydb.serverless.yandexcloud.net:2135'),
            database=os.getenv('YDB_DATABASE', '/ru-central1/b1g0uddo62cr7ku3vcrs/etn9qo0l4gl6admidgt1'),
            credentials=get_credentials()
        )
        return driver
    except Exception as e:
        logger.error(f"Error initializing YDB driver: {e}")
        raise

def main():
    """
    Main function to initialize YDB driver, query the database, and handle operations.
    """
    try:
        # Initialize driver and session pool
        driver = initialize_driver()

        with driver:
            driver.wait(fail_fast=True, timeout=5)

            # Use session pool with retry operation
            with ydb.SessionPool(driver) as pool:
                session = pool.acquire()
                if session:
                    result = retry_operation(execute_query, session)
                    assert result[0].rows[0].cnt == 1
                    logger.info("Query executed successfully.")
                else:
                    logger.error("Failed to acquire a session.")

    except Exception as e:
        logger.error(f"Error during execution: {e}")

if __name__ == "__main__":
    main()