ssh RTT tester

sshtester.py

# (C) 2015 Merlijn van Deen (valhallasw)
# Licensed under the MIT license
#
# pip install paramiko
#
#
import paramiko, time

import argparse
import math

parser = argparse.ArgumentParser(description='Measure SSH RTTs')
parser.add_argument('--host', help='the host to connect to', default='tools-login.wmflabs.org')
parser.add_argument('--user', help='the username to use', default='valhallasw')
parser.add_argument('--mode', choices=['char', 'line'], help='Measurement mode: single character or line-based', default='char')
parser.add_argument('--sleep', help='time to sleep between sends', default=0, type=float)
parser.add_argument('--tries', help='amount of RTTs to measure', default=1000, type=int)
parser.add_argument('--file', help='File to store measured RTTs (ms)', default=None)
args = parser.parse_args()


client = paramiko.SSHClient()
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
client.connect(args.host, username='valhallasw')


stdin, stdout, stderr = client.exec_command('cat', bufsize=0)

if args.file:
    f = open(args.file, 'w')
else:
    f = None

for i in range(args.tries):
    time.sleep(args.sleep)
    if args.mode == 'line':
        stdin.write(str(time.time()) + "\n")
        sentat = stdout.readline()
        deltat = time.time() - float(sentat.strip())
    elif args.mode == 'char':
        stdin.write("a")
        sentat = time.time()
        assert(stdout.read(1) == "a")
        deltat = time.time() - sentat

    print (deltat)*1000, "ms"
    if f:
        f.write(str(deltat * 1000) + "\n")