Use python paramiko to create a bastion host

Use python paramiko to create a bastion host
Bastion host-readme: (the database is mysql) 1. If the database does not exist, create a database, authorize the database user, create a table structure, and initialize some data. 2. If the database exists, go to Step 3. log on to the bastion host for verification. 4. If the bastion host user exists and the verification is successful, all the host groups of the bastion host user will be listed, and the number of hosts that can be used in the user's host group. 5. Select a host group to view the list of available hosts and users. 6. Select a user to enter a host or execute commands in batches. 7. If a bastion host user chooses to use a user to enter a single host, the user loads the local know_hosts file using paramiko for key verification and uses ssh to log on to the client host session to create a channel instance. Interact with the host, execute commands, and write data to the database in five or five records at the same time. 8. If you are a bastion host user, select to execute commands in batches. To create a multi-process pool, use paramiko to load the local know_hosts file, perform key verification, and connect to the client host using ssh. Execute the command, lock it, print the command result, and release the lock. Wait until all the processes in the process pool are executed, and prompt the user that all the processes have been executed.