ThinkPHP6实现高性能API网关开发实战：微服务架构核心组件

一、API网关核心功能设计

本案例实现以下核心功能：

动态路由转发：根据请求路径自动路由到不同微服务
请求聚合：单个API调用合并多个微服务请求
熔断降级：服务不可用时自动降级处理
限流控制：基于Redis的令牌桶限流算法
统一认证：JWT身份验证与权限控制

二、基础架构搭建

1. 项目初始化

composer create-project topthink/think tp6-gateway
cd tp6-gateway
composer require firebase/php-jwt

2. 目录结构设计

app/
├── controller/
│   └── Gateway.php   # 网关入口控制器
├── middleware/
│   ├── Auth.php      # 认证中间件
│   ├── RateLimit.php # 限流中间件
│   └── CircuitBreaker.php # 熔断中间件
├── service/
│   ├── Router.php    # 动态路由服务
│   ├── Aggregator.php # 请求聚合服务
│   └── HttpClient.php # HTTP客户端服务
config/
├── gateway.php       # 网关路由配置
└── services.php      # 微服务配置

三、核心服务实现

1. 动态路由服务

app/service/Router.php：

<?php
namespace appservice;

use thinkfacadeConfig;

class Router
{
    public static function dispatch($path)
    {
        $services = Config::get('services');
        $segments = explode('/', trim($path, '/'));
        
        foreach ($services as $prefix => $config) {
            if (strpos($path, "/$prefix/") === 0) {
                return [
                    'service' => $prefix,
                    'target' => $config['base_uri'] . 
                               substr($path, strlen($prefix) + 1)
                ];
            }
        }
        
        throw new Exception('Service not found');
    }
}

2. 请求聚合服务

app/service/Aggregator.php：

<?php
namespace appservice;

use thinkfacadeCache;

class Aggregator
{
    public static function aggregate(array $requests)
    {
        $client = new HttpClient();
        $results = [];
        
        foreach ($requests as $key => $request) {
            $cacheKey = 'agg:'.md5(json_encode($request));
            if ($data = Cache::get($cacheKey)) {
                $results[$key] = $data;
                continue;
            }
            
            $response = $client->request(
                $request['method'], 
                $request['url'],
                $request['data'] ?? []
            );
            
            Cache::set($cacheKey, $response, 60);
            $results[$key] = $response;
        }
        
        return $results;
    }
}

四、关键中间件实现

1. 熔断中间件

app/middleware/CircuitBreaker.php：

<?php
namespace appmiddleware;

use thinkfacadeCache;

class CircuitBreaker
{
    public function handle($request, Closure $next, $service)
    {
        $key = "circuit_breaker:$service";
        $state = Cache::get($key, 'closed');
        
        if ($state === 'open') {
            return $this->fallback($request, $service);
        }
        
        try {
            $response = $next($request);
            
            // 重置失败计数
            Cache::set("$key:failure_count", 0);
            return $response;
        } catch (Exception $e) {
            return $this->handleFailure($key, $request, $service);
        }
    }
    
    private function handleFailure($key, $request, $service)
    {
        $count = Cache::inc("$key:failure_count");
        
        if ($count >= 3) {
            Cache::set($key, 'open', 300); // 5分钟熔断
            Cache::set("$key:open_time", time());
        }
        
        return $this->fallback($request, $service);
    }
    
    private function fallback($request, $service)
    {
        // 返回预定义的降级响应
        return json([
            'code' => 503,
            'msg' => "服务暂时不可用",
            'data' => Config::get("fallback.$service", [])
        ]);
    }
}

五、网关入口控制器

app/controller/Gateway.php：

<?php
namespace appcontroller;

use thinkRequest;
use appserviceRouter;
use appserviceHttpClient;

class Gateway
{
    public function index(Request $request)
    {
        try {
            $route = Router::dispatch($request->pathinfo());
            
            $client = new HttpClient();
            $response = $client->request(
                $request->method(),
                $route['target'],
                $request->param()
            );
            
            return json($response);
        } catch (Exception $e) {
            return json([
                'code' => 404,
                'msg' => $e->getMessage()
            ], 404);
        }
    }
    
    public function aggregate(Request $request)
    {
        $requests = $request->param('requests');
        $results = Aggregator::aggregate($requests);
        
        return json([
            'code' => 200,
            'data' => $results
        ]);
    }
}