Installation ============ To install Scrapyrt:: pip install scrapyrt Now you can run Scrapyrt from within Scrapy project by just typing:: scrapyrt in Scrapy project directory. This should start server on port 9080. You may change the port server will listen to using ``-p`` option (see `Command line arguments`_):: scrapyrt -p 9081 Scrapyrt will look for ``scrapy.cfg`` file to determine your project settings, and will raise error if it won't find one. Note that you need to have all your project requirements installed. If you would like to play with source code and possibly contribute to the project, you can install Scrapyrt in 'dev' mode:: python setup.py develop with this mode of installation changes you made to Scrapyrt source will be reflected when you run ``scrapyrt`` command. In production you can run Scrapyrt from docker image provided by Scrapinghub. You only need to do following things:: docker pull scrapinghub/scrapyrt This will download Scrapyrt Docker image for you. Next step you need to run this image. Remember about providing proper port and project directory. Project directory from host machine must be mounted in directory /scrapyrt/project on guest. Following command will launch Scrapyrt forwarding port 9080 from guest to host, in demonized mode, with project directory in directory /home/user/quotesbot:: docker run -p 9080:9080 -tid -v /home/user/quotesbot:/scrapyrt/project scrapinghub/scrapyrt If you'd like to test if your virtual container is running just run:: docker ps this command should return container_id, image etc. Testing with curl:: curl -v "http://localhost:9080/crawl.json?url=http://example.com&spider_name=toscrape-css" | jq should return expected response. Scrapyrt HTTP API ================= Scrapyrt supports endpoint ``/crawl.json`` that can be requested with two methods. GET --- Arguments ~~~~~~~~~ Currently it accepts following arguments: spider_name - type: string - required Name of the spider to be scheduled. If spider is not found api will return 404. url - type: string - required if ``spider_start`` is not enabled Target URL. It should be URL-encoded, so that its query string will not interfere with API parameters. By default, the API will crawl this URL and will not send any other requests. Most importantly, it will not execute the spider ``start()`` or ``start_requests()`` methods. As a result, URLs defined in the ``start_urls`` spider attribute will not be visited. To change this, enable ``spider_start``. callback - type: string - optional Must exist as method of scheduled spider, does not need to contain string "self". If not passed default Scrapy callback `parse`_ will be used. If there is no spider method with name specified by callback argument or callback is not callable API will return 400 HTTP error. Example request with callback: ``/crawl.json?url=https://quotes.toscrape.com/&spider_name=toscrape-css&callback=parse_page`` errback - type: string - optional Scrapy errback for request made from spider. It must exist as method of scheduled spider, otherwise API will return 400 HTTP error. String does not need to contain 'self'. Defaults to None, can be adjusted with `DEFAULT_ERRBACK_NAME`_ setting. Example request with errback: ``/crawl.json?url=https://quotes.toscrape.com/&spider_name=toscrape-css&errback=my_errback`` max_requests - type: integer - optional Maximum amount of requests spider can generate. E.g. if it is set to ``1`` spider will only schedule one single request, other requests generated by spider (for example in callback, following links in first response) will be ignored. If your spider generates many requests in callback and you don't want to wait forever for it to finish you should probably pass it. spider_start - type: boolean - optional Whether to run the ``start()`` or ``start_requests()`` methods of the spider (``True``) or not (``False``, default). These methods are executed by default when you run a spider without ScrapyRT, but they are **not** executed by default when using ScrapyRT. By default we assume that the spider is expected to crawl **only** the URL provided in the ``url`` parameter, and not make any requests to e.g. the ``start_urls`` defined in the spider class. crawl_args - type: urlencoded JSON string - optional Optional arguments for spider. This is same as you use when running spider from command line with -a argument, for example if you run spider like this: "scrapy crawl spider -a zipcode=14100" you can send crawl_args={"zipcode":"14100"} (urlencoded: crawl_args=%7B%22zipcode%22%3A%2014100%7D) and spider will get zipcode argument. If required parameters are missing api will return 400 Bad Request with hopefully helpful error message. Examples ~~~~~~~~ To run sample `toscrape-css spider`_ from `Scrapy educational quotesbot project`_ parsing page about famous quotes:: curl "http://localhost:9080/crawl.json?spider_name=toscrape-css&url=http://quotes.toscrape.com/" To run same spider only allowing one request and parsing url with callback ``parse_foo``:: curl "http://localhost:9080/crawl.json?spider_name=toscrape-css&url=http://quotes.toscrape.com/&callback=parse_foo&max_requests=1" POST ---- Request body must contain valid JSON with information about request to be scheduled with spider and spider name. All positional and keyword arguments for `Scrapy Request`_ should be placed in request JSON key. Sample JSON:: { "request": { "url": "http://www.target.com/p/-/A-13631176", "callback": "parse_product", "dont_filter": "True" }, "spider_name": "target.com_products" } Slighty more complicated JSON:: { "request": { "url": "http://www.target.com/p/-/A-13631176", "meta": { "category": "some category", "item": { "discovery_item_id": "999" } }, "callback": "parse_product", "dont_filter": "True", "cookies": { "foo": "bar" } }, "spider_name": "target.com_products" } Arguments ~~~~~~~~~ JSON in POST body must have following keys: spider_name - type: string - required Name of the spider to be scheduled. If spider is not found api will return 404. max_requests - type: integer - optional Maximal amount of requests spider can generate. request - type: JSON object - required Should be valid JSON containing arguments to Scrapy request object that will be created and scheduled with spider. **request** JSON object must contain following keys: url - type: string - required It can contain all keyword arguments supported by `Scrapy Request`_ class. If required parameters are missing api will return 400 Bad Request with hopefully helpful error message. Examples ~~~~~~~~ To schedule spider toscrape-css with sample url using POST handler:: curl localhost:9080/crawl.json \ -d '{"request":{"url":"http://quotes.toscrape.com/"}, "spider_name": "toscrape-css"}' to schedule same spider with some meta that will be passed to spider request:: curl localhost:9080/crawl.json \ -d '{"request":{"url":"http://quotes.toscrape.com/", "meta": {"alfa":"omega"}}, "spider_name": "toscrape-css"}' Response -------- ``/crawl.json`` returns JSON object. Depending on whether request was successful or not fields in json object can vary. Success response ~~~~~~~~~~~~~~~~ JSON response for success has following keys: status Success response always have status "ok". spider_name Spider name from request. stats `Scrapy stats`_ from finished job. items List of scraped items. items_dropped List of dropped items. errors (optional) Contains list of strings with crawl errors tracebacks. Available only if `DEBUG`_ settings is set to ``True``. Example:: $ curl "http://localhost:9080/crawl.json?spider_name=toscrape-css&url=http://quotes.toscrape.com/" { "status": "ok" "spider_name": "toscrape-css", "stats": { "start_time": "2019-12-06 13:01:31", "finish_time": "2019-12-06 13:01:35", "finish_reason": "finished", "downloader/response_status_count/200": 10, "downloader/response_count": 11, "downloader/response_bytes": 24812, "downloader/request_method_count/GET": 11, "downloader/request_count": 11, "downloader/request_bytes": 2870, "item_scraped_count": 100, "log_count/DEBUG": 111, "log_count/INFO": 9, "response_received_count": 11, "scheduler/dequeued": 10, "scheduler/dequeued/memory": 10, "scheduler/enqueued": 10, "scheduler/enqueued/memory": 10, }, "items": [ { "text": ..., "author": ..., "tags": ... }, ... ], "items_dropped": [], } Error response ~~~~~~~~~~~~~~ JSON error response has following keys: status Error response always have status "error". code Duplicates HTTP response code. message Error message with some explanation why request failed. Example:: $ curl "http://localhost:9080/crawl.json?spider_name=foo&url=http://quotes.toscrape.com/" { "status": "error" "code": 404, "message": "Spider not found: foo", } Tweaking spiders for realtime ============================= If you have some standard values you would like to add to all requests generated from realtime api and you don't want to pass them in each GET request sent to api you can add a method ``modify_realtime_request`` to your spider, this method should accept request and return modified request you would like to send. API will execute this method, modify request and issue modified request. For example:: class SpiderName(Spider): name = "some_spider" def parse(self, response): pass def modify_realtime_request(self, request): request.meta["dont_redirect"] = True return request One more example (don't forget to import random):: class SpiderName(Spider): name = "some_other_spider" def parse(self, response): pass def modify_realtime_request(self, request): UA = [ 'Mozilla/5.0 (Windows NT 5.1; rv:31.0) Gecko/20100101 Firefox/31.0', 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2062.94 Safari/537.36', ] request.headers["User-Agent"] = random.choice(UA) return request Command line arguments ====================== Use ``scrapyrt -h`` to get help on command line options:: $ scrapyrt -h usage: scrapyrt [-h] [-p PORT] [-i IP] [--project PROJECT] [-s name=value] [-S project.settings] HTTP API server for Scrapy project. optional arguments: -h, --help show this help message and exit -p PORT, --port PORT port number to listen on -i IP, --ip IP IP address the server will listen on --project PROJECT project name from scrapy.cfg -s name=value, --set name=value set/override setting (may be repeated) -S project.settings, --settings project.settings custom project settings module path Configuration ============= You can pass custom settings to Scrapyrt using ``-S`` option (see `Command line arguments`_):: scrapyrt -S config Scrapyrt imports passed module, so it should be in one of the directories on ``sys.path``. Another way to configure server is to use ``-s key=value`` option:: scrapyrt -s TIMEOUT_LIMIT=120 Settings passed using ``-s`` option have the highest priority, settings passed in ``-S`` configuration module have priority higher than default settings. Available settings ------------------ SERVICE_ROOT ~~~~~~~~~~~~ Root server resource which is used to initialize Scrapyrt application. You can pass custom resource here and start Scrapyrt with it. Default: ``scrapyrt.resources.RealtimeApi``. CRAWL_MANAGER ~~~~~~~~~~~~~ Crawl manager that is used to create and control crawl. You can override default crawl manager and pass path to custom class here. Default: ``scrapyrt.core.CrawlManager``. RESOURCES ~~~~~~~~~ Dictionary where keys are resource URLs and values are resource classes. Used to setup Scrapyrt application with proper resources. If you want to add some additional resources - this is the place to add them. Default:: RESOURCES = { 'crawl.json': 'scrapyrt.resources.CrawlResource', } LOG_DIR ~~~~~~~ Path to directory to store crawl logs from running spiders. Default: ``log`` directory. TIMEOUT_LIMIT ~~~~~~~~~~~~~ Use this setting to limit crawl time. Default: ``1000``. DEBUG ~~~~~ Run Scrapyrt in debug mode - in case of errors you will get Python tracebacks in response, for example:: { "status": "ok" "spider_name": "toscrape-css", "stats": { "start_time": "2019-12-06 13:11:30" "spider_exceptions/Exception": 1, "finish_time": "2019-12-06 13:11:31", "finish_reason": "finished", "downloader/response_status_count/200": 1, "downloader/response_count": 2, "downloader/response_bytes": 2701, "downloader/request_method_count/GET": 2, "downloader/request_count": 2, "downloader/request_bytes": 446, "log_count/DEBUG": 2, "log_count/ERROR": 1, "log_count/INFO": 9, "response_received_count": 2, "scheduler/dequeued": 1, "scheduler/dequeued/memory": 1, "scheduler/enqueued": 1, "scheduler/enqueued/memory": 1 }, "items": [], "items_dropped": [], "errors": [ "Traceback (most recent call last): [...] \nexceptions.Exception: \n" ], } Default: ``True``. PROJECT_SETTINGS ~~~~~~~~~~~~~~~~ Automatically picked up from scrapy.cfg during initialization. LOG_FILE ~~~~~~~~ Path to file to store logs from Scrapyrt with daily rotation. Default: ``None``. Writing log to file is disabled by default. LOG_ENCODING ~~~~~~~~~~~~ Encoding that's used to encode log messages. Default: ``utf-8``. DEFAULT_ERRBACK_NAME ~~~~~~~~~~~~~~~~~~~~ Default: ``None`` String with the name of the default errback_. Use this setting to set default errback for scrapy spider requests made from ScrapyRT. Errback must exist as method of spider and must be callable, otherwise 400 HTTP error will be raised. .. _errback: https://docs.scrapy.org/en/latest/topics/request-response.htm#using-errbacks-to-catch-exceptions-in-request-processing Spider settings --------------- Scrapyrt overrides some Scrapy project settings by default and most importantly it disables some `Scrapy extensions`_:: "EXTENSIONS": { 'scrapy.contrib.logstats.LogStats': None, 'scrapy.webservice.WebService': None, 'scrapy.telnet.TelnetConsole': None, 'scrapy.contrib.throttle.AutoThrottle': None } There's usually no need and thus no simple way to change those settings, but if you have reason to do so you need to override ``get_project_settings`` method of ``scrapyrt.core.CrawlManager``. Logging ======= ScrapyRT supports Scrapy logging with some limitations. For each crawl it creates handler that's attached to the root logger and collects log records for which it can determine what spider object current log is related to. The only way to pass object to the log record is ``extra`` argument (see explanation and another usage example `here `_):: logger.debug('Log message', extra={'spider': spider}) Spider object is passed by default in `Spider.logger`_ and `Spider.log`_ backwards compatibility wrapper so you don't have to pass it yourself if you're using them. All logs record that don't have reference to spider object or reference another spider object in the same process will be ignored. Spider logging setup in ScrapyRT happens only after spider object instantiation, so logging from ``Spider.__init__`` method as well as logging during middleware, pipeline or extension instantiation is not supported due to limitations of initialization order in Scrapy. Also ScrapyRT doesn't support `LOG_STDOUT`_ - if you're using ``print`` statements in a spider they will never be logged to any log file. Reason behind this is that there's no way to filter such log records and they will appear in all log files for crawls that are running simultaneously. This is considered harmful and is not supported. But if you still want to save all stdout to some file - you can create custom `SERVICE_ROOT`_ where you can setup logging stdout to file using approach described in `Python Logging HOWTO`_ or redirect stdout to a file using `bash redirection syntax`_, `supervisord logging`_ etc. .. _toscrape-css spider: https://github.com/scrapy/quotesbot/blob/master/quotesbot/spiders/toscrape-css.py .. _Scrapy educational quotesbot project: https://github.com/scrapy/quotesbot .. _Scrapy Request: http://doc.scrapy.org/en/latest/topics/request-response.html#scrapy.http.Request .. _Scrapy Crawler: http://doc.scrapy.org/en/latest/topics/api.html#scrapy.crawler.Crawler .. _parse: http://doc.scrapy.org/en/latest/topics/spiders.html#scrapy.spider.Spider.parse .. _Scrapy stats: http://doc.scrapy.org/en/latest/topics/stats.html .. _Scrapy extensions: http://doc.scrapy.org/en/latest/topics/extensions.html .. _Python logging: https://docs.python.org/2/library/logging.html .. _Spider.logger: http://doc.scrapy.org/en/1.0/topics/spiders.html#scrapy.spiders.Spider.logger .. _Spider.log: http://doc.scrapy.org/en/1.0/topics/spiders.html#scrapy.spiders.Spider.log .. _LOG_STDOUT: http://doc.scrapy.org/en/latest/topics/settings.html#log-stdout .. _Python Logging HOWTO: https://docs.python.org/2/howto/logging.html .. _bash redirection syntax: http://www.gnu.org/software/bash/manual/html_node/Redirections.html .. _supervisord logging: http://supervisord.org/logging.html#child-process-logs