Python中如何使用thrift和zookeeper搭建一个简单的微服务demo

我来帮你用Python搭建一个基于Thrift和ZooKeeper的微服务demo。这个示例包含服务端和客户端，使用ZooKeeper作为服务注册中心。

首先安装依赖：

pip install thrift kazoo

1. 创建Thrift接口定义文件（calculator.thrift）

namespace py calculator

service CalculatorService {
    i32 add(1:i32 num1, 2:i32 num2),
    i32 subtract(1:i32 num1, 2:i32 num2)
}

2. 生成Python代码

thrift -gen py calculator.thrift

3. 服务端代码（server.py）

import json
from kazoo.client import KazooClient
from thrift.transport import TSocket
from thrift.transport import TTransport
from thrift.protocol import TBinaryProtocol
from thrift.server import TServer
from gen_py.calculator import CalculatorService

class CalculatorHandler:
    def add(self, num1, num2):
        return num1 + num2
    
    def subtract(self, num1, num2):
        return num1 - num2

def register_service(zk_hosts, service_name, host, port):
    """向ZooKeeper注册服务"""
    zk = KazooClient(hosts=zk_hosts)
    zk.start()
    
    # 创建服务节点路径
    service_path = f"/services/{service_name}"
    if not zk.exists(service_path):
        zk.create(service_path, makepath=True)
    
    # 创建临时节点存储服务地址
    node_data = json.dumps({"host": host, "port": port}).encode()
    node_path = f"{service_path}/node_"
    zk.create(node_path, node_data, ephemeral=True, sequence=True)
    
    print(f"服务注册成功: {node_path}")
    return zk

def main():
    handler = CalculatorHandler()
    processor = CalculatorService.Processor(handler)
    transport = TSocket.TServerSocket(host='127.0.0.1', port=9090)
    tfactory = TTransport.TBufferedTransportFactory()
    pfactory = TBinaryProtocol.TBinaryProtocolFactory()
    
    # 向ZooKeeper注册服务
    zk = register_service(
        zk_hosts='127.0.0.1:2181',
        service_name='calculator',
        host='127.0.0.1',
        port=9090
    )
    
    try:
        server = TServer.TSimpleServer(processor, transport, tfactory, pfactory)
        print("Calculator服务启动在端口 9090...")
        server.serve()
    finally:
        zk.stop()

if __name__ == '__main__':
    main()

4. 客户端代码（client.py）

import json
from kazoo.client import KazooClient
from thrift.transport import TSocket, TTransport
from thrift.protocol import TBinaryProtocol
from gen_py.calculator import CalculatorService

def discover_service(zk_hosts, service_name):
    """从ZooKeeper发现服务"""
    zk = KazooClient(hosts=zk_hosts)
    zk.start()
    
    service_path = f"/services/{service_name}"
    if not zk.exists(service_path):
        raise Exception(f"服务 {service_name} 不存在")
    
    # 获取所有服务节点
    children = zk.get_children(service_path)
    if not children:
        raise Exception(f"服务 {service_name} 没有可用实例")
    
    # 选择第一个可用节点（简单负载均衡）
    node_path = f"{service_path}/{children[0]}"
    data, _ = zk.get(node_path)
    service_info = json.loads(data.decode())
    
    zk.stop()
    return service_info['host'], service_info['port']

def main():
    # 发现服务
    host, port = discover_service('127.0.0.1:2181', 'calculator')
    
    # 创建Thrift客户端连接
    transport = TSocket.TSocket(host, port)
    transport = TTransport.TBufferedTransport(transport)
    protocol = TBinaryProtocol.TBinaryProtocol(transport)
    client = CalculatorService.Client(protocol)
    
    transport.open()
    
    try:
        # 调用服务
        result1 = client.add(10, 20)
        result2 = client.subtract(30, 15)
        print(f"10 + 20 = {result1}")
        print(f"30 - 15 = {result2}")
    finally:
        transport.close()

if __name__ == '__main__':
    main()

5. 运行步骤

1. 启动ZooKeeper服务
2. 运行服务端：python server.py
3. 运行客户端：python client.py

这个demo展示了微服务的核心概念：服务注册、服务发现和RPC调用。服务端启动时向ZooKeeper注册自己的地址，客户端通过查询ZooKeeper获取可用服务地址进行调用。

总结：Thrift负责RPC通信，ZooKeeper负责服务注册与发现。