堡垒机连接的服务器怎样断开

import paramiko
import time

def connect_bastion(host, port, username, password):
    client = paramiko.SSHClient()
    client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    client.connect(host, port, username, password)
    return client

def check_connection(client):
    try:
        transport = client.get_transport()
        if transport is not None and transport.is_active():
            return True
        else:
            return False
    except Exception as e:
        print(f"Connection check failed: {e}")
        return False

def main():
    bastion_host = 'bastion.example.com'
    bastion_port = 22
    username = 'admin'
    password = 'password'

    client = connect_bastion(bastion_host, bastion_port, username, password)

    while True:
        if not check_connection(client):
            print("Connection lost, reconnecting...")
            client.close()
            client = connect_bastion(bastion_host, bastion_port, username, password)
        time.sleep(10)

if __name__ == "__main__":
    main()