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Scrapy Item Pipeline that publishes to RabbitMQ
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import json | |
import pika | |
from scrapy.utils.serialize import ScrapyJSONEncoder | |
class RabbitMQItemPublisherPipeline(object): | |
def __init__(self, host, port, user, password, virtual_host, exchange, routing_key, queue): | |
self.host = host | |
self.port = port | |
self.user = user | |
self.password = password | |
self.virtual_host = virtual_host | |
credentials = pika.PlainCredentials(self.user, self.password) | |
parameters = pika.ConnectionParameters(self.host, | |
self.port, | |
self.virtual_host, | |
credentials) | |
# Connecting to RabbitMQ | |
self.connection = pika.BlockingConnection(parameters=parameters) | |
self.channel = self.connection.channel() | |
self.exchange = exchange | |
self.routing_key = routing_key | |
self.queue = queue | |
# Declaring RabbitMQ exchange | |
self.channel.exchange_declare(exchange=exchange, | |
exchange_type="direct", | |
durable=True) | |
# Decaling RabbitMQ queue | |
self.channel.queue_declare(queue=queue, | |
durable=True) | |
# Binding exchange + routing_key = queue | |
self.channel.queue_bind(exchange=exchange, | |
routing_key=routing_key, | |
queue=queue) | |
self.encoder = ScrapyJSONEncoder() | |
@classmethod | |
def from_crawler(cls, crawler): | |
# Creating a RabbitMQItemPublisherPipeline | |
return cls( | |
host=crawler.settings.get("RABBITMQ_HOST"), | |
port=crawler.settings.get("RABBITMQ_PORT"), | |
user=crawler.settings.get("RABBITMQ_USER"), | |
password=crawler.settings.get("RABBITMQ_PASSWORD"), | |
virtual_host=crawler.settings.get("RABBITMQ_VIRTUAL_HOST"), | |
exchange=crawler.settings.get("RABBITMQ_EXCHANGE"), | |
routing_key=crawler.settings.get("RABBITMQ_ROUTING_KEY"), | |
queue=crawler.settings.get("RABBITMQ_QUEUE"), | |
) | |
def close_spider(self, spider): | |
# Closing RabbitMQ channel and connection | |
self.channel.close() | |
self.connection.close() | |
def process_item(self, item, spider): | |
# Encoding item dict using Scrapy JSON Encoder | |
data = self.encoder.encode(item) | |
# Publishing item to exchange + routing_key = queue | |
self.channel.basic_publish( | |
exchange=self.exchange, | |
routing_key=self.routing_key, | |
body=data, | |
) | |
# Returning item to be processed | |
return item |
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