Scrapy Spider which reads from Warc file

Question

I am looking for a Scrapy Spider that instead of getting URL's and crawls them, it gets as input a WARC file (preferably from S3) and send to the parse method the content.

I actually need to skip all the download phase, that means that from start_requests method i would like to return a Response that will then send to the parse method.

This is what i have so far:

class WarcSpider(Spider):

    name = "warc_spider"

    def start_requests(self):
        f = warc.WARCFile(fileobj=gzip.open("file.war.gz"))
        for record in f:
            if record.type == "response":
                payload = record.payload.read()
                headers, body = payload.split('\r\n\r\n', 1)
                url=record['WARC-Target-URI']
                yield Response(url=url, status=200, body=body, headers=headers)


    def parse(self, response):
        #code that creates item
        pass

Any ideas of what is the Scarpy way of doing that ?

Answer 1

What you want to do is something like this:

class DummyMdw(object):

    def process_request(self, request, spider):
        record = request.meta['record']
        payload = record.payload.read()
        headers, body = payload.split('\r\n\r\n', 1)
        url=record['WARC-Target-URI']
        return Response(url=url, status=200, body=body, headers=headers)


class WarcSpider(Spider):

    name = "warc_spider"

    custom_settings = {
            'DOWNLOADER_MIDDLEWARES': {'x.DummyMdw': 1}
            }

    def start_requests(self):
        f = warc.WARCFile(fileobj=gzip.open("file.war.gz"))
        for record in f:
            if record.type == "response":
                yield Request(url, callback=self.parse, meta={'record': record})


    def parse(self, response):
        #code that creates item
        pass