exports.uploadFileToServer = function(filepath) {
var headers = { //定义符合上传API的请求头
    'Content-Type': 'multipart/form-data;boundary=------------ei4Ij5Ef1ae0ae0Ij5Ij5Ij5Ij5GI3', 
    'Content-Length': '1049', 'Connection': 'Keep-Alive', 'Pragma', 'no-cache' };
var reqos = {
    host: 'xxx.com',
    port: 80,
    path: '/fileupload',
    method: 'POST',
    headers: headers
};

var req = http.request(reqos, function(res) {
    console.log('STATUS: ' + res.statusCode);
    console.log('HEADERS: ' + JSON.stringify(res.headers));
    res.setEncoding('utf8');
    res.on('data', function (chunk) { //得到返回结果
        console.log('BODY: ' + chunk);
    });
});

// 向 request 体里面写入数据，只能是 string 或者 buffer
//req.write(filepath);
//我们要上传一个文件，所以要用到读取流
//创建一个文件读取流
var readStream = fs.createReadStream(filepath);
readStream.on('open', function () {
    // 等待读取流打开，然后写入到 req 对象中
    readStream.pipe(req);
});
// 捕获错误
readStream.on('error', function(err) {
  req.end(err);
});
req.end();
}