The simplest version#
Scrapy's built-in HttpProxyMiddleware reads request.meta[\"proxy\"] and handles credentials embedded in the URL. Set it in the spider and every request rotates on the gateway.
import scrapy
PROXY = "http://USER-cc-us:[email protected]:9000"
class PricesSpider(scrapy.Spider):
name = "prices"
start_urls = ["https://example.com/catalog"]
def start_requests(self):
for url in self.start_urls:
yield scrapy.Request(url, meta={"proxy": PROXY})
def parse(self, response):
for href in response.css("a.product::attr(href)").getall():
yield response.follow(href, callback=self.parse_product, meta={"proxy": PROXY})
def parse_product(self, response):
yield {"url": response.url, "price": response.css(".price::text").get()}A middleware for sticky sessions per item#
import hashlib
class ProxShiftMiddleware:
GATEWAY = "res.proxshift.com:9000"
def __init__(self, user, password, country):
self.user, self.password, self.country = user, password, country
@classmethod
def from_crawler(cls, crawler):
s = crawler.settings
return cls(s.get("PROXSHIFT_USER"), s.get("PROXSHIFT_PASS"), s.get("PROXSHIFT_COUNTRY", "us"))
def process_request(self, request, spider):
# Sticky when the request carries a session key (e.g. one per product flow), rotating otherwise
key = request.meta.get("session_key")
user = f"{self.user}-cc-{self.country}"
if key:
sid = hashlib.sha1(key.encode()).hexdigest()[:12]
user += f"-sid-{sid}-ttl-10m"
request.meta["proxy"] = f"http://{user}:{self.password}@{self.GATEWAY}"DOWNLOADER_MIDDLEWARES = {
"myproject.middlewares.ProxShiftMiddleware": 350, # before HttpProxyMiddleware (750)
}
PROXSHIFT_USER = "USER"
PROXSHIFT_PASS = "PASS"
PROXSHIFT_COUNTRY = "de"
CONCURRENT_REQUESTS = 32
CONCURRENT_REQUESTS_PER_DOMAIN = 8
AUTOTHROTTLE_ENABLED = True
AUTOTHROTTLE_TARGET_CONCURRENCY = 4.0
DOWNLOAD_TIMEOUT = 45
RETRY_ENABLED = True
RETRY_TIMES = 2
RETRY_HTTP_CODES = [403, 429, 500, 502, 503, 504, 522, 524]
COMPRESSION_ENABLED = TrueA retried request goes through the middleware again: without a session key it leaves from a new exit, which is exactly what you want after a 403 or 429. With a session key it stays on the same exit, which is what a multi-step flow needs.
Keeping the bill down#
- Scrapy does not load images or scripts; HTML and JSON only, so a page costs its HTML size.
- Enable compression (default) and avoid
Splashor browser rendering unless the data needs it. - Cache with
HTTPCACHE_ENABLED = Trueduring development so you do not pay to re-fetch the same pages while debugging selectors.
Per-domain politeness#
A pool is a way to be many polite visitors, not one impolite one. CONCURRENT_REQUESTS_PER_DOMAIN and AutoThrottle keep each target at a human-plausible rate per exit; the acceptable use policy forbids anything that looks like an attack.
Questions people ask#
Do I need scrapy-rotating-proxies?
Not with a gateway: rotation happens on the ProxShift side for every new connection. That package manages lists of static proxies; with res.proxshift.com there is one proxy to configure.
How do I use a different country per request?
Set request.meta["country"] in the spider and read it in the middleware to build the -cc- parameter; the example uses a single setting for brevity.