Constrained Network test does not fail fast under fatal conditions.

media/tools/constrained_network_server/cns.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Constrained Network Server. Serves files with supplied network constraints.
 
 The CNS exposes a web based API allowing network constraints to be imposed on
 file serving.
 
 TODO(dalecurtis): Add some more docs here.
 
 """
 
+import logging
 import mimetypes
 import optparse
 import os
 import signal
 import sys
 import threading
 import time
 import traffic_control
 
 try:
   import cherrypy
 except ImportError:
   print ('CNS requires CherryPy v3 or higher to be installed. Please install\n'
          'and try again. On Linux: sudo apt-get install python-cherrypy3\n')
   sys.exit(1)
 
 # Add webm file types to mimetypes map since cherrypy's default type is text.
 mimetypes.types_map['.webm'] = 'video/webm'
 
+# Default logging is ERROR. Use --verbose to enable DEBUG logging.
+_DEFAULT_LOG_LEVEL = logging.ERROR
+
 # Default port to serve the CNS on.
 _DEFAULT_SERVING_PORT = 9000
 
 # Default port range for constrained use.
 _DEFAULT_CNS_PORT_RANGE = (50000, 51000)
 
 # Default number of seconds before a port can be torn down.
 _DEFAULT_PORT_EXPIRY_TIME_SECS = 5 * 60
 
 
@@ skipping 236 matching lines @@
   parser.add_option('--interface', default='eth0',
                     help=('Interface to setup constraints on. Use lo for a '
                           'local client. Default: %default'))
   parser.add_option('--threads', type='int',
                     default=cherrypy._cpserver.Server.thread_pool,
                     help=('Number of threads in the thread pool. Default: '
                           '%default'))
   parser.add_option('--www-root', default=os.getcwd(),
                     help=('Directory root to serve files from. Defaults to the '
                           'current directory: %default'))
+  parser.add_option('-v', '--verbose', action='store_true', dest='verbose',
+                    default=False, help='Turn on verbose output.')
 
   options = parser.parse_args()[0]
 
   # Convert port range into the desired tuple format.
   try:
     if isinstance(options.port_range, str):
       options.port_range = [int(port) for port in options.port_range.split(',')]
   except ValueError:
     parser.error('Invalid port range specified.')
 
   # Convert the path to an absolute to remove any . or ..
   options.www_root = os.path.abspath(options.www_root)
 
+  # Required so that cherrypy logs do not get propagated to root logger causing
+  # the logs to be printed twice.
+  cherrypy.log.error_log.propagate = False
+
+  _SetLogger(options.verbose)
+
   return options
 
 
+def _SetLogger(verbose):
+  # Logging is used for traffic_control debug statements.
+  log_level = _DEFAULT_LOG_LEVEL
+  if verbose:
+    log_level = logging.DEBUG
+  logging.basicConfig(level=log_level, format='%(message)s')

[DaleCurtis, 2012/01/06 23:19:42]

Need a more descriptive message here. One that is more similar to cherrypy.log.
Since multiple requests will be coming in at once, it will be impossible to
differentiate them w/o more detail.

[shadi, 2012/01/07 04:56:19]

cherrypy.log only shows date. I added thread number to the format, the date is
printed automatically.
On 2012/01/06 23:19:42, DaleCurtis wrote:

[DaleCurtis, 2012/01/09 19:21:19]

Ah, I'm thinking of cherrypy.request.log() I think. The logs I've seen show the
request IP and some other information in addition to the timestamp.

We should probably be using that instead to make sure logs can be read easily.

+
+
+def _CheckRootAccess():

[DaleCurtis, 2012/01/06 23:19:42]

This is not complete and should instead be in the traffic_control library.

Something like: CheckRequirements() throws an exception if a requirement is
missing.

By not complete I mean you need to check if 'sudo -n [tc|iptables]' passes w/o
input (as mentioned in the ticket).

[shadi, 2012/01/07 04:56:19]

Check http://codereview.chromium.org/9125022/
On 2012/01/06 23:19:42, DaleCurtis wrote:

+  if os.geteuid() != 0:
+    sys.exit('Need root access to run a constrained server.')
+
+
 def Main():
   """Configure and start the ConstrainedNetworkServer."""
   options = ParseArgs()
+  _CheckRootAccess()
 
   cherrypy.config.update(
       {'server.socket_host': '::', 'server.socket_port': options.port})
 
   if options.threads:
     cherrypy.config.update({'server.thread_pool': options.threads})
 
   # Setup port allocator here so we can call cleanup on failures/exit.
   pa = PortAllocator(options.port_range, expiry_time_secs=options.expiry_time)
 
   try:
     cherrypy.quickstart(ConstrainedNetworkServer(options, pa))
   finally:
     # Disable Ctrl-C handler to prevent interruption of cleanup.
     signal.signal(signal.SIGINT, lambda signal, frame: None)
     pa.Cleanup(options.interface, all_ports=True)
 
 
 if __name__ == '__main__':
   Main()