demo: new ping monitoring script and option to stop demo after some time

See "./demo --help" for more information.

/reviewed-on !8

README.rst

@@ -58,13 +58,14 @@ Requirements
 - Babel_ (with Nexedi patches)
 - geoip2: `python library`_ and `country lite database`_ (optional)
 - python-miniupnpc for UPnP support (optional)
-- for the demo: miniupnpd_, Graphviz, Screen_, Nemu_
+- for the demo: miniupnpd_, Graphviz, Screen_, Nemu_, MultiPing_
 
 See also `setup.py` for Python dependencies.
 
 .. _Babel: https://lab.nexedi.com/nexedi/babeld
 .. _Nemu: https://github.com/thetincho/nemu
 .. _miniupnpd: http://miniupnp.free.fr/
+.. _MultiPing: https://github.com/romana/multi-ping
 .. _Screen: http://savannah.gnu.org/projects/screen
 .. _python library: https://pypi.org/project/geoip2/
 .. _country lite database: https://dev.maxmind.com/geoip/geoip2/geolite2/

demo/demo

 #!/usr/bin/python2
-import math, nemu, os, re, signal, socket, subprocess, sys, time, weakref
+import argparse, math, nemu, os, re, signal
+import socket, subprocess, sys, time, weakref
 from collections import defaultdict
 IPTABLES = 'iptables'
 SCREEN = 'screen'
@@ -38,6 +39,22 @@ def _add_interface(node, iface):
     return Node__add_interface(node, iface)
 nemu.Node._add_interface = _add_interface
 
+parser = argparse.ArgumentParser()
+parser.add_argument('port', type = int,
+    help = 'port used to display tunnels')
+parser.add_argument('-d', '--duration', type = int,
+    help = 'time of the demo execution in seconds')
+parser.add_argument('-p', '--ping', action = 'store_true',
+    help = 'execute ping utility')
+args = parser.parse_args()
+
+def handler(signum, frame):
+    sys.exit()
+
+if args.duration:
+    signal.signal(signal.SIGALRM, handler)
+    signal.alarm(args.duration)
+
 execfile("fixnemu.py")
 
 # create nodes
@@ -225,6 +242,18 @@ if 1:
     re6stnet(machine8, 'm8')
     db.close()
 
+if args.ping:
+    for j, machine in enumerate(nodes):
+        ips = [
+            '2001:db8:42::1' if i == 0 else
+            '2001:db8:42:2::' if i == 2 else
+            # Only 1 address for machine2 because prefix_len = 80,+48 = 128
+            '2001:db8:42:%s::1' % i
+            for i in xrange(9)
+            if i != j]
+        name = 'm' + machine.short if machine.short != 'R' else 'registry'
+        machine.screen('python ping.py {} {}'.format(name, ' '.join(ips)))
+
 _ll = {}
 def node_by_ll(addr):
     try:
@@ -302,7 +331,7 @@ def route_svg(ipv4, z = 4, default = type('', (), {'short': None})):
         stdin=subprocess.PIPE, stdout=subprocess.PIPE,
         ).communicate('\n'.join(gv))[0]
 
-if len(sys.argv) > 1:
+if args.port:
     import SimpleHTTPServer, SocketServer
 
     class Handler(SimpleHTTPServer.SimpleHTTPRequestHandler):
@@ -392,6 +421,6 @@ if len(sys.argv) > 1:
     class TCPServer(SocketServer.TCPServer):
         allow_reuse_address = True
 
-    TCPServer(('', int(sys.argv[1])), Handler).serve_forever()
+    TCPServer(('', args.port), Handler).serve_forever()
 
 import pdb; pdb.set_trace()

demo/ping.py

+# -*- coding: utf-8 -*-
+'''
+Script launched on machines from the demo with the option -p/--ping
+It uses Multiping to ping several IPs passed as arguments.
+After Re6st is stable, this script logs when it does not get response from a
+machine in a csv file stored in the directory of the machine in this format:
+time, sequence number, number of non-responding machines, ip of these machines
+'''
+import argparse, errno, logging, os, socket, time
+from multiping import MultiPing
+from threading import Thread, Lock
+
+PING_INTERVAL = 0.1
+PING_TIMEOUT = 4
+csv_lock = Lock()
+
+class MultiPing(MultiPing):
+    # Patch of Multiping because it stays blocked to ipv4
+    # emission when we want to ping only ipv6 addresses.
+    # So we only keep the ipv6 part for the demo.
+    # Bug issued: https://github.com/romana/multi-ping/issues/22
+    def _read_all_from_socket(self, timeout):
+        pkts = []
+        if self._ipv6_address_present:
+            try:
+                self._sock6.settimeout(timeout)
+                while True:
+                    p = self._sock6.recv(128)
+                    pkts.append((bytearray(p), time.time()))
+                    self._sock6.settimeout(0)
+            except socket.timeout:
+                pass
+            except socket.error as e:
+                if e.errno == errno.EWOULDBLOCK:
+                    pass
+                else:
+                    raise
+        return pkts
+
+class Ping(Thread):
+
+    seq = None
+    seq_lock = Lock()
+
+    def run(self):
+        mp = MultiPing(addrs)
+        assert mp._last_used_id is None
+        cls = self.__class__
+        with cls.seq_lock:
+            mp._last_used_id = cls.seq
+            mp.send()
+            seq = cls.seq = mp._last_used_id
+        responses, no_responses = mp.receive(PING_TIMEOUT)
+        x = list(responses)
+        x += no_responses
+        assert sorted(x) == sorted(addrs), (addrs, responses, no_responses)
+        with csv_lock:
+            if no_responses:
+                my_csv.write('%r,%d,%d,%s\n' % (time.time(), seq,
+                            len(no_responses), ' '.join(no_responses)))
+                my_csv.flush()
+            else :
+                # Update modification/access time of csv
+                os.utime(csv_path, (time.time(), time.time()))
+
+        for add in no_responses:
+            print('No response from %s with seq no %d' % (add, seq))
+
+parser = argparse.ArgumentParser()
+parser.add_argument('n', help = 'my machine name (m1,m2...)')
+parser.add_argument('a', nargs = '+', help = 'the list of addresses to ping')
+args = parser.parse_args()
+my_name = args.n
+addrs = args.a
+
+print('Waiting for every machine to answer ping..')
+while True:
+    mp = MultiPing(addrs)
+    mp.send()
+    _, no_responses = mp.receive(0.5)
+    if not no_responses:
+        break
+    # Currently useless because MultiPing does not return earlier if it
+    # couldn't send any ping (e.g. no route to host). Let's hope it will
+    # improve.
+    time.sleep(PING_INTERVAL)
+print('Network is stable, starting to ping..')
+
+csv_path = '{}/ping_logs.csv'.format(my_name)
+my_csv = open(csv_path, 'w+')
+my_csv.write('%r,%s,%d\n' % (time.time(), 0, 0))
+my_csv.flush()
+
+while True:
+    Ping().start()
+    time.sleep(PING_INTERVAL)

demo/py

@@ -6,11 +6,12 @@ def __file__():
     from argparse import ArgumentParser
     _parse_args = ArgumentParser.parse_args
     ArgumentParser.parse_args = lambda self: _parse_args(self, sys.argv[2:])
+    # Always import to prevent re6st.node.cli from altering the first sys.path
+    from re6st import registry
 
     if 1:
         # Check renewal of certificate.
         from random import randrange
-        from re6st import registry
         registry.RENEW_PERIOD = 60
         _createCertificate = registry.RegistryServer.createCertificate
         def createCertificate(self, client_prefix, *args):