326 lines
9.7 KiB
JavaScript
326 lines
9.7 KiB
JavaScript
// 配置常量
|
||
const CONFIG = {
|
||
DEEPSEEK_API_URL: 'https://api.deepseek.com/chat/completions',
|
||
MAX_BODY_SIZE: 1024 * 1024, // 1MB
|
||
REQUEST_TIMEOUT: 30000, // 30秒
|
||
VALIDATE_REQUEST_BODY: false, // 是否验证请求体格式（设为 true 启用严格验证）
|
||
DEFAULT_MODEL: 'deepseek-chat', // 默认模型
|
||
SUPPORTED_MODELS: [
|
||
'deepseek-chat', // 通用对话模型 (DeepSeek-V3)
|
||
'deepseek-reasoner' // 推理模型 (DeepSeek-R1)
|
||
]
|
||
};
|
||
|
||
// CORS 响应头
|
||
const CORS_HEADERS = {
|
||
'Access-Control-Allow-Origin': '*',
|
||
'Access-Control-Allow-Methods': 'POST, GET, OPTIONS',
|
||
'Access-Control-Allow-Headers': 'Content-Type, Authorization',
|
||
'Access-Control-Max-Age': '86400',
|
||
};
|
||
|
||
// 安全响应头
|
||
const SECURITY_HEADERS = {
|
||
'X-Content-Type-Options': 'nosniff',
|
||
'X-Frame-Options': 'DENY',
|
||
'X-XSS-Protection': '1; mode=block',
|
||
'Referrer-Policy': 'strict-origin-when-cross-origin',
|
||
};
|
||
|
||
// 辅助函数：验证认证
|
||
function validateAuth(request, env) {
|
||
const expectedAuth = env.PROXY_KEY ? `Bearer ${env.PROXY_KEY}` : null;
|
||
const gotAuth = request.headers.get('authorization') || '';
|
||
return !expectedAuth || gotAuth === expectedAuth;
|
||
}
|
||
|
||
// 辅助函数：创建错误响应
|
||
function createErrorResponse(error, status = 500, details = null) {
|
||
const errorBody = {
|
||
error,
|
||
timestamp: new Date().toISOString(),
|
||
...(details && { details })
|
||
};
|
||
|
||
return new Response(JSON.stringify(errorBody), {
|
||
status,
|
||
headers: {
|
||
'Content-Type': 'application/json',
|
||
'Cache-Control': 'no-cache',
|
||
...CORS_HEADERS,
|
||
...SECURITY_HEADERS,
|
||
}
|
||
});
|
||
}
|
||
|
||
// 辅助函数：创建成功响应
|
||
function createResponse(body, status = 200, headers = {}) {
|
||
return new Response(body, {
|
||
status,
|
||
headers: {
|
||
...headers,
|
||
...CORS_HEADERS,
|
||
...SECURITY_HEADERS,
|
||
}
|
||
});
|
||
}
|
||
|
||
// 辅助函数：验证Content-Type
|
||
function validateContentType(request) {
|
||
const contentType = request.headers.get('content-type') || '';
|
||
if (!contentType.includes('application/json')) {
|
||
throw new Error('Invalid content type. Expected application/json');
|
||
}
|
||
}
|
||
|
||
// 辅助函数：验证请求体大小
|
||
function validateContentLength(request) {
|
||
const contentLength = parseInt(request.headers.get('content-length') || '0');
|
||
if (contentLength > CONFIG.MAX_BODY_SIZE) {
|
||
throw new Error(`Request body too large. Maximum size: ${CONFIG.MAX_BODY_SIZE} bytes`);
|
||
}
|
||
}
|
||
|
||
// 辅助函数：验证单个消息格式
|
||
function validateSingleMessage(message) {
|
||
if (!message.role || !message.content) {
|
||
throw new Error('Invalid request format. Each message must have role and content');
|
||
}
|
||
if (!['system', 'user', 'assistant', 'tool'].includes(message.role)) {
|
||
throw new Error('Invalid request format. Invalid message role');
|
||
}
|
||
}
|
||
|
||
// 辅助函数：验证消息数组
|
||
function validateMessages(messages) {
|
||
if (!messages || !Array.isArray(messages)) {
|
||
throw new Error('Invalid request format. Missing or invalid messages array');
|
||
}
|
||
|
||
if (messages.length === 0) {
|
||
throw new Error('Invalid request format. Messages array cannot be empty');
|
||
}
|
||
|
||
for (const message of messages) {
|
||
validateSingleMessage(message);
|
||
}
|
||
}
|
||
|
||
// 辅助函数：验证模型（警告但不阻止）
|
||
function validateModel(model) {
|
||
if (model && !CONFIG.SUPPORTED_MODELS.includes(model)) {
|
||
console.warn(`Unsupported model: ${model}, supported models: ${CONFIG.SUPPORTED_MODELS.join(', ')}`);
|
||
// 注意：这里只是警告，不阻止请求，让 DeepSeek API 自己处理
|
||
}
|
||
}
|
||
|
||
// 辅助函数：验证请求体内容
|
||
async function validateRequestBody(request) {
|
||
try {
|
||
const body = await request.clone().json();
|
||
validateMessages(body.messages);
|
||
validateModel(body.model);
|
||
} catch (e) {
|
||
if (e.message.includes('Invalid request format')) {
|
||
throw e;
|
||
}
|
||
throw new Error('Invalid JSON format');
|
||
}
|
||
}
|
||
|
||
// 辅助函数：验证请求
|
||
async function validateRequest(request) {
|
||
validateContentType(request);
|
||
validateContentLength(request);
|
||
|
||
if (CONFIG.VALIDATE_REQUEST_BODY) {
|
||
await validateRequestBody(request);
|
||
}
|
||
}
|
||
|
||
// 辅助函数：发送上游请求
|
||
async function sendUpstreamRequest(request, env) {
|
||
const controller = new AbortController();
|
||
const timeoutId = setTimeout(() => {
|
||
controller.abort();
|
||
}, CONFIG.REQUEST_TIMEOUT);
|
||
|
||
try {
|
||
const accept = request.headers.get('accept') || 'application/json';
|
||
const contentType = request.headers.get('content-type') || 'application/json';
|
||
|
||
// 处理请求体，确保有默认模型
|
||
let requestBody;
|
||
try {
|
||
const bodyText = await request.text();
|
||
const body = JSON.parse(bodyText);
|
||
|
||
// 如果没有指定模型，使用默认模型
|
||
if (!body.model) {
|
||
body.model = CONFIG.DEFAULT_MODEL;
|
||
console.log(`No model specified, using default: ${CONFIG.DEFAULT_MODEL}`);
|
||
}
|
||
|
||
requestBody = JSON.stringify(body);
|
||
} catch (err) {
|
||
// 如果解析失败，使用原始请求体（让上游API处理错误）
|
||
console.warn('Failed to parse request body for model injection:', err.message);
|
||
requestBody = await request.text();
|
||
}
|
||
|
||
const upstream = await fetch(CONFIG.DEEPSEEK_API_URL, {
|
||
method: 'POST',
|
||
signal: controller.signal,
|
||
headers: {
|
||
'Authorization': `Bearer ${env.DEEPSEEK_API_KEY}`,
|
||
'Content-Type': contentType,
|
||
'Accept': accept,
|
||
'User-Agent': 'AI-Proxy-Worker/1.0',
|
||
},
|
||
body: requestBody,
|
||
});
|
||
|
||
clearTimeout(timeoutId);
|
||
|
||
// 记录请求日志
|
||
console.log('DeepSeek API request:', {
|
||
status: upstream.status,
|
||
statusText: upstream.statusText,
|
||
timestamp: new Date().toISOString(),
|
||
});
|
||
|
||
return upstream;
|
||
} catch (err) {
|
||
clearTimeout(timeoutId);
|
||
|
||
if (err.name === 'AbortError') {
|
||
throw new Error('Request timeout');
|
||
}
|
||
throw err;
|
||
}
|
||
}
|
||
|
||
// 辅助函数：处理简单路由
|
||
function handleSimpleRoutes(request, url) {
|
||
// 处理 OPTIONS 请求（CORS 预检）
|
||
if (request.method === 'OPTIONS') {
|
||
return createResponse(null, 200, CORS_HEADERS);
|
||
}
|
||
|
||
// 健康检查
|
||
if (request.method === 'GET' && url.pathname === '/') {
|
||
return createResponse(JSON.stringify({
|
||
status: 'ok',
|
||
service: 'AI Proxy Worker',
|
||
timestamp: new Date().toISOString()
|
||
}), 200, { 'Content-Type': 'application/json' });
|
||
}
|
||
|
||
return null;
|
||
}
|
||
|
||
// 辅助函数：处理错误响应
|
||
function handleError(err, request, url, startTime) {
|
||
const duration = Date.now() - startTime;
|
||
|
||
console.error('Request failed:', {
|
||
error: err.message,
|
||
duration: `${duration}ms`,
|
||
method: request.method,
|
||
pathname: url.pathname,
|
||
timestamp: new Date().toISOString(),
|
||
});
|
||
|
||
// 根据错误类型返回不同的状态码
|
||
if (err.message.includes('Invalid content type')) {
|
||
return createErrorResponse('invalid_content_type', 400, err.message);
|
||
}
|
||
if (err.message.includes('Request body too large')) {
|
||
return createErrorResponse('payload_too_large', 413, err.message);
|
||
}
|
||
if (err.message.includes('Invalid request format') || err.message.includes('Invalid JSON')) {
|
||
return createErrorResponse('invalid_request', 400, err.message);
|
||
}
|
||
if (err.message.includes('Request timeout')) {
|
||
return createErrorResponse('timeout', 504, 'Request to DeepSeek API timed out');
|
||
}
|
||
|
||
// 通用错误
|
||
return createErrorResponse('internal_error', 500, 'An unexpected error occurred');
|
||
}
|
||
|
||
export default {
|
||
/**
|
||
* Cloudflare Workers entry point
|
||
* AI Proxy Worker - Universal AI API proxy with enhanced error handling and security
|
||
*
|
||
* Current Version (v1.0): DeepSeek API support
|
||
* - deepseek-chat: General conversation model
|
||
* - deepseek-reasoner: Complex reasoning model
|
||
*
|
||
* Future Versions: Multi-AI support planned (OpenAI, Claude, Gemini)
|
||
*/
|
||
async fetch(request, env) {
|
||
const url = new URL(request.url);
|
||
const startTime = Date.now();
|
||
|
||
try {
|
||
// 处理简单路由
|
||
const simpleResponse = handleSimpleRoutes(request, url);
|
||
if (simpleResponse) return simpleResponse;
|
||
|
||
// 只允许 POST /chat
|
||
if (request.method !== 'POST' || url.pathname !== '/chat') {
|
||
return createErrorResponse('not_found', 404, 'Endpoint not found');
|
||
}
|
||
|
||
// 验证认证
|
||
if (!validateAuth(request, env)) {
|
||
return createErrorResponse('unauthorized', 401, 'Invalid or missing authorization');
|
||
}
|
||
|
||
// 检查必需的环境变量
|
||
if (!env.DEEPSEEK_API_KEY) {
|
||
console.error('Missing DEEPSEEK_API_KEY environment variable');
|
||
return createErrorResponse('configuration_error', 500, 'Service configuration error');
|
||
}
|
||
|
||
// 验证请求
|
||
await validateRequest(request);
|
||
|
||
// 发送上游请求
|
||
const upstream = await sendUpstreamRequest(request, env);
|
||
|
||
// 处理上游错误
|
||
if (!upstream.ok) {
|
||
const errorText = await upstream.text();
|
||
console.error('DeepSeek API error:', {
|
||
status: upstream.status,
|
||
statusText: upstream.statusText,
|
||
body: errorText,
|
||
timestamp: new Date().toISOString(),
|
||
});
|
||
|
||
return createErrorResponse('api_error', upstream.status, {
|
||
upstream_status: upstream.status,
|
||
upstream_message: upstream.statusText
|
||
});
|
||
}
|
||
|
||
// 返回成功响应
|
||
const responseHeaders = {
|
||
'Content-Type': upstream.headers.get('Content-Type') || 'application/json',
|
||
'Cache-Control': 'no-store, no-transform',
|
||
};
|
||
|
||
const duration = Date.now() - startTime;
|
||
console.log(`Request completed successfully in ${duration}ms`);
|
||
|
||
return createResponse(upstream.body, upstream.status, responseHeaders);
|
||
|
||
} catch (err) {
|
||
return handleError(err, request, url, startTime);
|
||
}
|
||
},
|
||
};
|