Node.js 您如何写入 aws lambda 实例的文件系统

我try 写入aws lambda实例的文件系统失败.The docs say表示标准lambda实例在/tmp/时有512mb的可用空间.但是，在我的本地计算机上运行的以下代码在lambda实例上根本不起作用:

  var fs = require('fs');
  fs.writeFile("/tmp/test.txt", "testing", function(err) {
      if(err) {
          return console.log(err);
      }
      console.log("The file was saved!");
  });

匿名回调函数中的代码永远不会在lambda实例上被调用.有人成功过吗？非常感谢你的帮助.

这可能是一个相关的question.s3代码和我试图使用fs回调函数进行的操作之间是否可能存在某种冲突？下面的代码是当前正在运行的代码.

console.log('Loading function');

var aws = require('aws-sdk');
var s3 = new aws.S3({ apiVersion: '2006-03-01' });
var fs = require('fs');

exports.handler = function(event, context) {
    //console.log('Received event:', JSON.stringify(event, null, 2));

    // Get the object from the event and show its content type
    var bucket = event.Records[0].s3.bucket.name;
    var key = decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, ' '));
    var params = {
        Bucket: bucket,
        Key: key
    };
    s3.getObject(params, function(err, data) {
        if (err) {
            console.log(err);
            var message = "Error getting object " + key + " from bucket " + bucket +
            ". Make sure they exist and your bucket is in the same region as this function.";
            console.log(message);
            context.fail(message);
        } else {

            //console.log("DATA: " + data.Body.toString());
            fs.writeFile("/tmp/test.csv", "testing", function (err) {

                if(err) {
                    context.failed("writeToTmp Failed " + err);
                } else {
                    context.succeed("writeFile succeeded");
                }
            });
        }
    });
};