Make graphs of Pings to an IP. For troubleshooting my adsl connection.

pynger.py

'''
Pynger:

App that pings a given IP address and saves the pings in the file.

Usage:
    pynger.py [ip]

    ip: the IP address to be pinged. If this is left empty it will default to
    the ADSL router I hit first.

    To stop the app, hit ctrl-c

    This will save the plot as a png and a text file with timestamps and pings
    in ms will be written to a file.

'''
import sys
import time
import datetime
import subprocess
from collections import namedtuple

import matplotlib.style
matplotlib.style.use('ggplot')
import matplotlib.pyplot as plt


class Pinger(object):
    '''
    Class that handles sending pings and returning the stats
    '''

    def __init__(self, ip):

        '''
        Initialise the pinger

        ip: ip address to which this pinger sends packets. <str>
        '''

        self.ip = ip
        self.pings = []

    def ping(self):

        '''
        Sends a ping to the IP.

        Adds the ping to self.pings.

        Returns the last ping as namedtuple.
        '''

        cmd = ['ping', '-c', '1', '-q', '-t', '1', self.ip]
        proc = subprocess.Popen(cmd, stdout=subprocess.PIPE,
                                stderr=subprocess.PIPE)
        pings, error = proc.communicate()

        if error:
            pings = -1.0
        else:
            pings = pings.split('\n')[-2].split('=')[-1]
            pings = pings.split('/')[0].strip()

        p = namedtuple('Ping', ['timestamp', 'latency'])
        p.timestamp = datetime.datetime.now()
        p.latency = float(pings)

        self.pings.append(p)

        return p

    def save_to_file(self):
        '''
        Save pings to text file in the format:
            timestamp ping

        where timestamp is in iso format and ping in ms. If the ping wasn't
        received it is saved as -1.

        file is named by ip address
        '''
        with open('{}.txt'.format(self.ip), 'a') as outputfile:
            # write a header if the file doesn't exist
            if not outputfile.tell():
                outputfile.write("# Pings to IP: {}\n".format(self.ip))
                outputfile.write("# DATE     TIME            PING (ms)\n")

            for p in self.pings:
                outputfile.write("{} {}\n".format(p.timestamp, p.latency))


class PingPlotter(object):

    '''
    Realtime plotter

    '''

    def __init__(self):

        '''
        Initialise the matplotlib plotter

        '''
        plt.ion()
        self.fig = plt.figure()
        self.ax1 = self.fig.add_subplot(111)
        self.line, = self.ax1.plot([], [], linewidth=2)

        plt.ylabel('Ping (ms)')
        plt.xlabel('Time')
        plt.subplots_adjust(left=0.1, bottom=0.1)

        plt.show()

    def update(self, pinger):

        '''
        Update the plots.

        pinger: instance of pinger class

        '''

        # get times and latencies as lists
        timestamps = [p.timestamp for p in pinger.pings]
        latency = [p.latency for p in pinger.pings]
        plt.title('Pings to {}'.format(pinger.ip))
        self.line.set_xdata(timestamps)
        self.line.set_ydata(latency)
        self.ax1.relim()
        self.ax1.autoscale_view()
        plt.gcf().autofmt_xdate()

        plt.draw()


if __name__ == "__main__":

    # Default to the MWEB IP if none given

    if len(sys.argv) < 2:
        pinger = Pinger('197.84.96.137')
    else:
        ip = sys.argv[1]
        pinger = Pinger(ip)

    plotter = PingPlotter()

    while True:
        try:
            pinger.ping()
            plotter.update(pinger)
            time.sleep(0.5)
        except KeyboardInterrupt:
            pinger.save_to_file()
            plt.savefig('{}-pings.png'.format(pinger.ip))
            sys.exit()