概述
RabbitMQ 是一个开源的消息代理和队列服务器，实现 [AMQP 0-9-1] 标准。本教程将指导你如何使用 Python 和 RabbitMQ 进行消息传递。
安装与配置
安装 RabbitMQ
1. Ubuntu:
```bash
sudo apt-get update
sudo apt-get install rabbitmq-server
```
2. Windows:
- 下载安装包并运行。
配置
- 启动管理插件以在浏览器中查看队列状态:
```bash
sudo rabbitmq-plugins enable rabbitmq_management
```
- 访问管理界面: `http://localhost:15672/` (默认用户名和密码都是 guest)。
发布/订阅模式
创建发布者
```python
import pika
connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
channel.exchange_declare(exchange='logs', exchange_type='fanout')
message = "Hello, world!"
channel.basic_publish(exchange='logs', routing_key='', body=message)
print(" [x] Sent %r" % message)
connection.close()
```
创建订阅者
```python
import pika
def callback(ch, method, properties, body):
print(" [x] Received %r" % body)
connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
channel.exchange_declare(exchange='logs', exchange_type='fanout')
result = channel.queue_declare(queue='', exclusive=True)
queue_name = result.method.queue
channel.queue_bind(exchange='logs', queue=queue_name)
print(' [*] Waiting for logs. To exit press CTRL+C')
channel.basic_consume(queue=queue_name, on_message_callback=callback, auto_ack=True)
channel.start_consuming()
```
工作队列
创建任务发布者
```python
import pika
connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
channel.queue_declare(queue='task_queue', durable=True)
message = "A new task"
channel.basic_publish(
exchange='',
routing_key='task_queue',
body=message,
properties=pika.BasicProperties(
delivery_mode=pika.spec.PERSISTENT_DELIVERY_MODE
))
print(" [x] Sent 'A new task'")
connection.close()
```
创建任务消费者
```python
import pika
import time
def callback(ch, method, properties, body):
print(" [x] Received %r" % body.decode())
time.sleep(body.count(b'.'))
print(" [x] Done")
ch.basic_ack(delivery_tag=method.delivery_tag)
connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
channel.queue_declare(queue='task_queue', durable=True)
print(' [*] Waiting for messages. To exit press CTRL+C')
channel.basic_qos(prefetch_count=1)
channel.basic_consume(queue='task_queue', on_message_callback=callback)
channel.start_consuming()
```
路由模式
创建路由发布者
```python
import pika
connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
channel.exchange_declare(exchange='direct_logs', exchange_type='direct')
severity = "info"
message = f"Info: Hello World!"
channel.basic_publish(
exchange='direct_logs',
routing_key=severity,
body=message)
print(" [x] Sent %r:%r" % (severity, message))
connection.close()
```
创建路由消费者
```python
import pika
def callback(ch, method, properties, body):
print(" [x] Received %r" % body)
connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
channel.exchange_declare(exchange='direct_logs', exchange_type='direct')
result = channel.queue_declare(queue='', exclusive=True)
queue_name = result.method.queue
severities = ['error', 'warning']
for severity in severities:
channel.queue_bind(
exchange='direct_logs',
queue=queue_name,
routing_key=severity)
channel.basic_consume(queue=queue_name, on_message_callback=callback, auto_ack=True)
print(' [*] Waiting for logs. To exit press CTRL+C')
channel.start_consuming()
```
主题模式
创建主题发布者
```python
import pika
connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
channel.exchange_declare(exchange='topic_logs', exchange_type='topic')
routing_key = "kern.critical"
message = "A critical kernel error"
channel.basic_publish(
exchange='topic_logs',
routing_key=routing_key,
body=message)
print(" [x] Sent %r:%r" % (routing_key, message))
connection.close()
```
创建主题消费者
```python
import pika
def callback(ch, method, properties, body):
print(" [x] Received %r" % body)
connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
channel.exchange_declare(exchange='topic_logs', exchange_type='topic')
result = channel.queue_declare(queue='', exclusive=True)
queue_name = result.method.queue
binding_keys = ['kern.*', '*.critical']
for binding_key in binding_keys:
channel.queue_bind(
exchange='topic_logs',
queue=queue_name,
routing_key=binding_key)
channel.basic_consume(queue=queue_name, on_message_callback=callback, auto_ack=True)
print(' [*] Waiting for logs. To exit press CTRL+C')
channel.start_consuming()
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