.. _topics-telnetconsole: ============== Telnet Console ============== .. module:: scrapy.telnet :synopsis: The Telnet Console Scrapy comes with a built-in telnet console for inspecting and controlling a Scrapy running process. The telnet console is just a regular python shell running inside the Scrapy process, so you can do literally anything from it. The telnet console is a :ref:`built-in Scrapy extension ` which comes enabled by default, but you can also disable it if you want. For more information about the extension itself see :ref:`topics-extensions-ref-telnetconsole`. .. highlight:: none How to access the telnet console ================================ The telnet console listens in the TCP port defined in the :setting:`TELNETCONSOLE_PORT` setting, which defaults to ``6023``. To access the console you need to type:: telnet localhost 6023 >>> You need the telnet program which comes installed by default in Windows, and most Linux distros. Available variables in the telnet console ========================================= The telnet console is like a regular Python shell running inside the Scrapy process, so you can do anything from it including importing new modules, etc. However, the telnet console comes with some default variables defined for convenience: +----------------+-------------------------------------------------------------------+ | Shortcut | Description | +================+===================================================================+ | ``crawler`` | the Scrapy Crawler object (``scrapy.crawler``) | +----------------+-------------------------------------------------------------------+ | ``engine`` | the Scrapy Engine object (``scrapy.core.engine``) | +----------------+-------------------------------------------------------------------+ | ``spider`` | the spider object (only if there is a single spider opened) | +----------------+-------------------------------------------------------------------+ | ``slot`` | the engine slot (only if there is a single spider opened) | +----------------+-------------------------------------------------------------------+ | ``extensions`` | the Extension Manager (``scrapy.project.crawler.extensions``) | +----------------+-------------------------------------------------------------------+ | ``stats`` | the Stats Collector (``scrapy.stats.stats``) | +----------------+-------------------------------------------------------------------+ | ``settings`` | the Scrapy settings object (``scrapy.conf.settings``) | +----------------+-------------------------------------------------------------------+ | ``est`` | print a report of the current engine status | +----------------+-------------------------------------------------------------------+ | ``prefs`` | for memory debugging (see :ref:`topics-leaks`) | +----------------+-------------------------------------------------------------------+ | ``p`` | a shortcut to the `pprint.pprint`_ function | +----------------+-------------------------------------------------------------------+ | ``hpy`` | for memory debugging (see :ref:`topics-leaks`) | +----------------+-------------------------------------------------------------------+ .. _pprint.pprint: http://docs.python.org/library/pprint.html#pprint.pprint Telnet console usage examples ============================= Here are some example tasks you can do with the telnet console: View engine status ------------------ You can use the ``est()`` method of the Scrapy engine to quickly show its state using the telnet console:: telnet localhost 6023 >>> est() Execution engine status time()-engine.start_time : 21.3188259602 engine.is_idle() : False engine.has_capacity() : True engine.scheduler.is_idle() : False len(engine.scheduler.pending_requests) : 1 engine.downloader.is_idle() : False len(engine.downloader.slots) : 1 engine.scraper.is_idle() : False len(engine.scraper.slots) : 1 Spider: engine.spider_is_idle(spider) : False engine.slots[spider].closing : False len(engine.scheduler.pending_requests[spider]) : 11504 len(engine.downloader.slots[spider].queue) : 9 len(engine.downloader.slots[spider].active) : 17 len(engine.downloader.slots[spider].transferring) : 8 engine.downloader.slots[spider].lastseen : 1311311093.61 len(engine.scraper.slots[spider].queue) : 0 len(engine.scraper.slots[spider].active) : 0 engine.scraper.slots[spider].active_size : 0 engine.scraper.slots[spider].itemproc_size : 0 engine.scraper.slots[spider].needs_backout() : False Pause, resume and stop the Scrapy engine ---------------------------------------- To pause:: telnet localhost 6023 >>> engine.pause() >>> To resume:: telnet localhost 6023 >>> engine.unpause() >>> To stop:: telnet localhost 6023 >>> engine.stop() Connection closed by foreign host. Telnet Console signals ====================== .. signal:: update_telnet_vars .. function:: update_telnet_vars(telnet_vars) Sent just before the telnet console is opened. You can hook up to this signal to add, remove or update the variables that will be available in the telnet local namespace. In order to do that, you need to update the ``telnet_vars`` dict in your handler. :param telnet_vars: the dict of telnet variables :type telnet_vars: dict Telnet settings =============== These are the settings that control the telnet console's behaviour: .. setting:: TELNETCONSOLE_PORT TELNETCONSOLE_PORT ------------------ Default: ``[6023, 6073]`` The port range to use for the etlnet console. If set to ``None`` or ``0``, a dynamically assigned port is used. .. setting:: TELNETCONSOLE_HOST TELNETCONSOLE_HOST ------------------ Default: ``'0.0.0.0'`` The interface the telnet console should listen on