Add prometheus counters, logConnection test, monitoring test

exitstats.py

@@ -10,6 +10,8 @@
 import os
 from collections import namedtuple
 
+import prometheus_client as prom
+
 try:
   from Web100 import *
 except ImportError:
@@ -43,6 +45,14 @@
 "WAD_CwndAdjust"
 ]
 
+PROMETHEUS_SERVER_PORT = 9090
+connection_count = prom.Counter('connection_count',
+                                'Count of connections logged')
+plc_connection_count = prom.Counter('plc_connection_count',
+                                    'Count of connections to Planet Lab')
+main_loop_count = prom.Counter('main_loop_count',
+                               'Count of main loop iterations')
+
 active_vars=None
 def setkey(snap):
   """
@@ -166,8 +176,12 @@ def logConnection(c):
   if snap["RemAddress"] == "127.0.0.1":
     return
   if snap["RemAddress"].startswith("128.112.139"):
+    plc_connection_count.inc()
     return
 
+  # Count only the remote connections.
+  connection_count.inc()
+
   # pick/open a logfile as needed, based on the close poll time
   t = time.time()
   logf = getLogFile(t, snap["LocalAddress"])
@@ -190,9 +204,13 @@ def main(argv):
     print "Usage: %s [server_name]"%argv[0]
     return 0
 
+  # Start prometheus server to export metrics.
+  prom.start_http_server(PROMETHEUS_SERVER_PORT)
+
   agent = Web100Agent()
   closed = []
   while True:
+    main_loop_count.inc()
     conns = agent.all_connections()
     newclosed = []
     for c in conns:

exitstats_test.py

@@ -9,10 +9,49 @@
 import unittest
 import time
 from test.test_support import EnvironmentVarGuard
+import prometheus_client as prom
+import urllib2
 
 import exitstats
-
-class ExitstatsTest(unittest.TestCase):
+class FakeConnection():
+  '''Substitute for Web100 connection object for testing.'''
+  cid = 0
+  values = {}
+
+  def readall(self):
+    '''Returns dictionary of metrics'''
+    return self.values
+
+  def setall(self, v):
+    self.values = v
+
+  def copy(self):
+    result = FakeConnection()
+    result.cid = self.cid
+    result.values = self.values
+    return result
+
+  def __iter__(self):
+    return values.__iter__()
+
+class TestMonitoring(unittest.TestCase):
+  def setUp(self):
+    prom.start_http_server(exitstats.PROMETHEUS_SERVER_PORT)
+
+  def testConnectionCount(self):
+    c1 = FakeConnection()
+    c1.cid = 1234
+    c1.setall({"RemAddress": "5.4.3.2", "LocalAddress": "1.2.3.4", "other": "other"})
+    exitstats.setkey(c1.values)
+    exitstats.logConnection(c1)
+
+    # Read from the httpserver and assert the correct connection count.
+    print("http://localhost:%s"%(exitstats.PROMETHEUS_SERVER_PORT))
+    response = urllib2.urlopen(
+        "http://localhost:%s"%(exitstats.PROMETHEUS_SERVER_PORT)).read()
+    self.assertTrue("connection_count 1.0" in response)
+
+class TestExitstats(unittest.TestCase):
   def remove_file(self, logdir, logname):
     ''' Utility to remove a file and its directory'''
     try:

requirements.txt

@@ -0,0 +1,2 @@
+prometheus_client
+