Multiprocessing demo for PyEZ

program-output

ncatania-mbp:Python ncatania$ python3 pyez-multiprocessing-demo.py

Number of processes (devices that will be processed simultaneously): 3

Connecting to 172.16.141.140...       <--- "vsrx1"
Connecting to 172.16.141.141...       <--- "vsrx2"
Connecting to 172.16.141.142...       <--- "vsrx3"
Connected to 172.16.141.140 OK!
Connected to 172.16.141.141 OK!
Connected to 172.16.141.142 OK!

*** Got Device Facts! ***
Hostname: vsrx1, Serial#: 6EXXXXXXXXXX
**********

Connecting to 172.16.141.143...       <--- "vsrx4"

*** Got Device Facts! ***
Hostname: vsrx3, Serial#: 6EXXXXXXXXXX
**********

*** Got Device Facts! ***
Hostname: vsrx2, Serial#: 6EXXXXXXXXXX
**********

Connecting to 172.16.141.144...       <--- "vsrx5"
Connecting to 172.16.141.145...       <--- "vsrx6"
Connected to 172.16.141.143 OK!
Connected to 172.16.141.144 OK!
Connected to 172.16.141.145 OK!

*** Got Device Facts! ***
Hostname: vsrx4, Serial#: 6EXXXXXXXXXX
**********

*** Got Device Facts! ***
Hostname: vsrx5, Serial#: 6EXXXXXXXXXX
**********

*** Got Device Facts! ***
Hostname: vsrx6, Serial#: 6EXXXXXXXXXX
**********

pyez-multiprocessing-demo.py

from multiprocessing import Pool
from jnpr.junos import Device
from jnpr.junos.exception import ConnectError


def connect(host):

    # CREDENTIALS - Change as required
    username = "lab"
    passwd = "lab123"
    sshkey = "/path/to/sshkey.pem"

    # Connect to the device - Remove passwd/sshkey parameters as required
    dev = Device(host=host, user=username, passwd=passwd, ssh_private_key_file=sshkey)

    try:
        print ("Connecting to {}...".format(host))
        dev.open()
    except ConnectError as err:
        print ("Cannot connect to device: {0}".format(err))
        return None
    except Exception as err:
        print ("Cannot connect to device: {0}".format(err))
        return None
    else:
        print ("Connected to {} OK!".format(host))

    ###
    # Do some stuff with the device
    ###

    # Eg: Prints hostname and serial number from device facts
    print ("*** Got Device Facts! ***\nHostname: {}, Serial#: {}\n**********\n".format(dev.facts['hostname'], dev.facts['serialnumber']))

    ###

    # Close connection to the device
    dev.close()


if __name__ == '__main__':
    
    # List of hosts to connect to
    hosts = ["172.16.141.140", "172.16.141.141", "172.16.141.142", "172.16.141.143", "172.16.141.144", "172.16.141.145"]

    processes = 3  # Number of processes to create for multiprocessing. BE CAREFUL WITH THIS!

    print("\nNumber of processes (devices that will be processed simultaneously): {}\n".format(processes))
    
    # pool.map will call the connect() function and pass a single element from hosts as the parameter.
    # This is repeated for the length of hosts.
    # If process limit is reached (eg: 3), then pool.map will wait until one of the 3 processes completes before calling connect() with the next hosts parameter.
    pool = Pool(processes=processes)
    pool.map(connect, hosts)
    pool.close()
    pool.join()