110 lines
3.7 KiB
JavaScript
110 lines
3.7 KiB
JavaScript
const http = require('http');
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const url = require('url');
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const path = require('path');
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const fs = require('fs');
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const sharp = require('sharp');
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const PORT = process.env.PORT || 3000;
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const IMAGE_BASE_DIR = process.env.IMAGE_BASE_DIR || '/app/images';
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/**
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* 安全检查：防止路径遍历攻击（如 ../../etc/passwd）
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* @param {string} targetPath 目标文件路径
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* @param {string} baseDir 基础目录
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* @returns {boolean} 是否合法
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*/
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function isSafePath(targetPath, baseDir) {
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const resolvedTarget = path.resolve(targetPath).toLowerCase();
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const resolvedBase = path.resolve(baseDir).toLowerCase();
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return resolvedTarget.startsWith(resolvedBase);
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}
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/**
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* 发送错误响应
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* @param {http.ServerResponse} res 响应对象
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* @param {number} statusCode 状态码
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* @param {string} message 错误信息
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*/
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function sendError(res, statusCode, message) {
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res.writeHead(statusCode, { 'Content-Type': 'text/plain; charset=utf-8' });
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res.end(message);
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}
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const server = http.createServer(async (req, res) => {
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if (req.method !== 'GET') {
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return sendError(res, 405, '仅支持GET请求');
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}
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try {
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const parsedUrl = url.parse(req.url, true);
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const requestPath = parsedUrl.pathname;
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const query = parsedUrl.query;
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// 过滤根路径请求（避免直接访问服务根目录）
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if (requestPath === '/') {
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return sendError(res, 200, `
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图片处理服务已启动！
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使用示例：
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1. 访问原图片：http://localhost:${PORT}/a/b/c.png
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2. 调整质量：http://localhost:${PORT}/a/b/c.png?q=80
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图片基础目录：${IMAGE_BASE_DIR}
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`);
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}
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const requestedFilePath = requestPath.slice(1);
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const fullImagePath = path.join(IMAGE_BASE_DIR, requestedFilePath);
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// 安全检查：防止路径遍历
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if (!isSafePath(fullImagePath, IMAGE_BASE_DIR)) {
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return sendError(res, 403, '访问拒绝：非法路径（路径遍历攻击）');
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}
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if (!fs.existsSync(fullImagePath)) {
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return sendError(res, 404, `图片不存在：${requestedFilePath}`);
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}
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if (!query.q) {
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const fileStream = fs.createReadStream(fullImagePath);
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const ext = path.extname(fullImagePath).slice(1); // 如 png/jpg
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res.writeHead(200, { 'Content-Type': `image/${ext}` });
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// 流式传输文件（适合大文件）
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fileStream.pipe(res);
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fileStream.on('error', (err) => {
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sendError(res, 500, `读取文件失败：${err.message}`);
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});
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return;
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}
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const quality = parseInt(query.q);
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if (isNaN(quality)) {
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return sendError(res, 400, '质量参数q必须是数字（1-100）');
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}
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const finalQuality = Math.max(1, Math.min(100, quality));
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const imageBuffer = await sharp(fullImagePath).rotate().jpeg({ quality: finalQuality }).toBuffer();
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res.writeHead(200, {
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'Content-Type': 'image/jpeg',
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'Content-Length': imageBuffer.length
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});
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res.end(imageBuffer);
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} catch (error) {
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console.error('服务器异常：', error);
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sendError(res, 500, `服务器内部错误：${error.message}`);
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}
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});
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// ===================== 启动服务器 =====================
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server.listen(PORT, '0.0.0.0', () => {
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console.log(`服务地址：http://0.0.0.0:${PORT}`);
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});
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// 捕获全局未处理异常
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process.on('uncaughtException', (err) => {
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console.error('全局未捕获异常：', err);
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});
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process.on('unhandledRejection', (reason) => {
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console.error('全局未处理Promise拒绝：', reason);
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});
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