Использование ProcessPoolExecutor

Интерфейс модуля concurrent.futures очень удобен тем, что переход с потоков на процессы делается заменой ThreadPoolExecutor на ProcessPoolExecutor, поэтому все примеры ниже полностью аналогичны примерам с потоками.

Метод map

Для того чтобы использовать процессы вместо потоков, достаточно сменить ThreadPoolExecutor на ProcessPoolExecutor:

from concurrent.futures import ProcessPoolExecutor
from pprint import pprint
from datetime import datetime
import time
from itertools import repeat
import logging

import yaml
from netmiko import ConnectHandler, NetMikoAuthenticationException


logging.getLogger('paramiko').setLevel(logging.WARNING)

logging.basicConfig(
    format = '%(threadName)s %(name)s %(levelname)s: %(message)s',
    level=logging.INFO)


def send_show(device_dict, command):
    start_msg = '===> {} Connection: {}'
    received_msg = '<=== {} Received:   {}'
    ip = device_dict['ip']
    logging.info(start_msg.format(datetime.now().time(), ip))
    if ip == '192.168.100.1': time.sleep(5)

    try:
        with ConnectHandler(**device_dict) as ssh:
            ssh.enable()
            result = ssh.send_command(command)
            logging.info(received_msg.format(datetime.now().time(), ip))
        return result
    except NetMikoAuthenticationException as err:
        logging.warning(err)


def send_command_to_devices(devices, command):
    data = {}
    with ProcessPoolExecutor(max_workers=2) as executor:
        result = executor.map(send_show, devices, repeat(command))
        for device, output in zip(devices, result):
            data[device['ip']] = output
    return data


if __name__ == '__main__':
    with open('devices.yaml') as f:
        devices = yaml.safe_load(f)
    pprint(send_command_to_devices(devices, 'sh clock'))

Результат выполнения:

$ python netmiko_processes_map.py
MainThread root INFO: ===> 08:35:50.931629 Connection: 192.168.100.2
MainThread root INFO: ===> 08:35:50.931295 Connection: 192.168.100.1
MainThread root INFO: <=== 08:35:56.353774 Received:   192.168.100.2
MainThread root INFO: ===> 08:35:56.469854 Connection: 192.168.100.3
MainThread root INFO: <=== 08:36:01.410230 Received:   192.168.100.1
MainThread root INFO: <=== 08:36:02.067678 Received:   192.168.100.3
{'192.168.100.1': '*08:36:01.242 UTC Fri Jul 26 2019',
 '192.168.100.2': '*08:35:56.185 UTC Fri Jul 26 2019',
 '192.168.100.3': '*08:36:01.900 UTC Fri Jul 26 2019'}

Метод submit

Файл netmiko_processes_submit_exception.py:

from concurrent.futures import ProcessPoolExecutor, as_completed
from pprint import pprint
from datetime import datetime
import time
from itertools import repeat
import logging

import yaml
from netmiko import ConnectHandler
from netmiko.ssh_exception import NetMikoAuthenticationException

logging.getLogger("paramiko").setLevel(logging.WARNING)

logging.basicConfig(
    format = '%(threadName)s %(name)s %(levelname)s: %(message)s',
    level=logging.INFO)

start_msg = '===> {} Connection: {}'
received_msg = '<=== {} Received: {}'


def send_show(device_dict, command):
    ip = device_dict['ip']
    logging.info(start_msg.format(datetime.now().time(), ip))
    if ip == '192.168.100.1': time.sleep(5)
    with ConnectHandler(**device_dict) as ssh:
        ssh.enable()
        result = ssh.send_command(command)
        logging.info(received_msg.format(datetime.now().time(), ip))
    return {ip: result}


def send_command_to_devices(devices, command):
    data = {}
    with ProcessPoolExecutor(max_workers=2) as executor:
        future_ssh = [
            executor.submit(send_show, device, command) for device in devices
        ]
        for f in as_completed(future_ssh):
            try:
                result = f.result()
            except NetMikoAuthenticationException as e:
                print(e)
            else:
                data.update(result)
    return data


if __name__ == '__main__':
    with open('devices.yaml') as f:
        devices = yaml.safe_load(f)
    pprint(send_command_to_devices(devices, 'sh clock'))

Результат выполнения:

$ python netmiko_processes_submit_exception.py
MainThread root INFO: ===> 08:38:08.780267 Connection: 192.168.100.1
MainThread root INFO: ===> 08:38:08.781355 Connection: 192.168.100.2
MainThread root INFO: <=== 08:38:14.420339 Received: 192.168.100.2
MainThread root INFO: ===> 08:38:14.529405 Connection: 192.168.100.3
MainThread root INFO: <=== 08:38:19.224554 Received: 192.168.100.1
MainThread root INFO: <=== 08:38:20.162920 Received: 192.168.100.3
{'192.168.100.1': '*08:38:19.058 UTC Fri Jul 26 2019',
 '192.168.100.2': '*08:38:14.250 UTC Fri Jul 26 2019',
 '192.168.100.3': '*08:38:19.995 UTC Fri Jul 26 2019'}