Make telnet console and web service try a range of ports for binding, instead of just one. Closes #226

docs/topics/settings.rst

@@ -962,9 +962,9 @@ will be enabled (provided its extension is also enabled).
 TELNETCONSOLE_PORT
 ------------------
 
-Default: ``6023``
+Default: ``[6023, 6073]``
 
-The port to use for the telnet console. If set to ``None`` or ``0``, a
+The port range to use for the telnet console. If set to ``None`` or ``0``, a
 dynamically assigned port is used. For more info see
 :ref:`topics-telnetconsole`.
 

docs/topics/webservice.rst

@@ -131,10 +131,10 @@ the log is sent to standard scrapy log.
 WEBSERVICE_PORT
 ---------------
 
-Default: ``6080``
+Default: ``[6080, 7030]``
 
-The port to use for the web service. If set to ``None`` or ``0``, a dynamically
-assigned port is used.
+The port range to use for the web service. If set to ``None`` or ``0``, a
+dynamically assigned port is used.
 
 WEBSERVICE_RESOURCES
 --------------------

scrapy/conf/default_settings.py

@@ -251,11 +251,11 @@ URLLENGTH_LIMIT = 2083
 USER_AGENT = '%s/%s' % (BOT_NAME, BOT_VERSION)
 
 TELNETCONSOLE_ENABLED = 1
-TELNETCONSOLE_PORT = 6023  # if None, uses a dynamic port
+TELNETCONSOLE_PORT = [6023, 6073]
 
 WEBSERVICE_ENABLED = True
 WEBSERVICE_LOGFILE = None
-WEBSERVICE_PORT = 6080
+WEBSERVICE_PORT = [6080, 7030]
 WEBSERVICE_RESOURCES = {}
 WEBSERVICE_RESOURCES_BASE = {
     'scrapy.contrib.webservice.crawler.CrawlerResource': 1,

scrapy/telnet.py

@@ -8,16 +8,17 @@ import pprint
 
 from twisted.conch import manhole, telnet
 from twisted.conch.insults import insults
-from twisted.internet import reactor, protocol
+from twisted.internet import protocol
 
 from scrapy.xlib.pydispatch import dispatcher
 from scrapy.exceptions import NotConfigured
 from scrapy.project import crawler
 from scrapy.stats import stats
-from scrapy import signals
+from scrapy import log, signals
 from scrapy.utils.signal import send_catch_log
 from scrapy.utils.trackref import print_live_refs
 from scrapy.utils.engine import print_engine_status
+from scrapy.utils.reactor import listen_tcp
 from scrapy.conf import settings
 
 try:
@@ -37,12 +38,14 @@ class TelnetConsole(protocol.ServerFactory):
         if not settings.getbool('TELNETCONSOLE_ENABLED'):
             raise NotConfigured
         self.noisy = False
-        self.portnum = settings.getint('TELNETCONSOLE_PORT')
+        self.portrange = map(int, settings.getlist('TELNETCONSOLE_PORT'))
         dispatcher.connect(self.start_listening, signals.engine_started)
         dispatcher.connect(self.stop_listening, signals.engine_stopped)
 
     def start_listening(self):
-        self.port = reactor.listenTCP(self.portnum, self)
+        self.port = listen_tcp(self.portrange, self)
+        log.msg("Telnet console listening on port %d" % self.port.getHost().port,
+            log.DEBUG)
 
     def stop_listening(self):
         self.port.stopListening()

scrapy/utils/reactor.py

@@ -0,0 +1,15 @@
+from twisted.internet import reactor, error
+
+def listen_tcp(portrange, factory):
+    """Like reactor.listenTCP but tries different ports in a range."""
+    assert len(portrange) in [1, 2], "invalid portrange: %s" % portrange
+    if not hasattr(portrange, '__iter__'):
+        return reactor.listenTCP(portrange, factory)
+    if len(portrange) == 1:
+        return reactor.listenTCP(portrange[0], factory)
+    for x in range(portrange[0], portrange[1]+1):
+        try:
+            return reactor.listenTCP(x, factory)
+        except error.CannotListenError:
+            if x == portrange[1]:
+                raise

scrapy/webservice.py

@@ -1,19 +1,19 @@
 """
 Scrapy web services extension
 
-See docs/topics/ws.rst
+See docs/topics/webservice.rst
 """
 
-from twisted.internet import reactor
 from twisted.web import server, error
 
 from scrapy.xlib.pydispatch import dispatcher
 from scrapy.exceptions import NotConfigured
-from scrapy import signals
+from scrapy import log, signals
 from scrapy.utils.jsonrpc import jsonrpc_server_call
 from scrapy.utils.serialize import ScrapyJSONEncoder, ScrapyJSONDecoder
 from scrapy.utils.misc import load_object
 from scrapy.utils.txweb import JsonResource as JsonResource_
+from scrapy.utils.reactor import listen_tcp
 from scrapy.utils.conf import build_component_list
 from scrapy.conf import settings
 
@@ -67,7 +67,7 @@ class WebService(server.Site):
         if not settings.getbool('WEBSERVICE_ENABLED'):
             raise NotConfigured
         logfile = settings['WEBSERVICE_LOGFILE']
-        self.portnum = settings.getint('WEBSERVICE_PORT')
+        self.portrange = map(int, settings.getlist('WEBSERVICE_PORT'))
         root = RootResource()
         reslist = build_component_list(settings['WEBSERVICE_RESOURCES_BASE'], \
             settings['WEBSERVICE_RESOURCES'])
@@ -80,7 +80,9 @@ class WebService(server.Site):
         dispatcher.connect(self.stop_listening, signals.engine_stopped)
 
     def start_listening(self):
-        self.port = reactor.listenTCP(self.portnum, self)
+        self.port = listen_tcp(self.portrange, self)
+        log.msg("Web service listening on port %d" % self.port.getHost().port,
+            log.DEBUG)
 
     def stop_listening(self):
         self.port.stopListening()