Question

我正在尝试编写一个lambda脚本，它可以从站点中提取图像并将其存储在S3中。我遇到的问题是将Body属性传递给S3.putObject方法的对象是什么类型。在文档here中，它说它应该是new Buffer('...') || 'STRING_VALUE' || streamObject，但我不确定如何将https响应转换为其中之一。这是我尝试过的：

var AWS = require('aws-sdk');
var https = require('https');
var Readable = require('stream').Readable;
var s3 = new AWS.S3();
var fs = require('fs');

var url = 'https://upload.wikimedia.org/wikipedia/commons/thumb/1/1d/AmazonWebservices_Logo.svg/500px-AmazonWebservices_Logo.svg.png';

exports.handler = function(event, context) {
  https.get(url, function(response) {
    var params = {
     Bucket: 'example',
     Key: 'aws-logo.png',
     Body: response  // fs.createReadStream(response); doesn't work, arg should be a path to a file...
                     // just putting response errors out with "Cannot determine length of [object Object]"
    };

    s3.putObject(params, function(err, data) {
      if (err) {
        console.error(err, err.stack);
      } else {
        console.log(data);
      }
    });
  });
};

Answer 1

如评论中所示，Lambda允许在/tmp中保存文件。但你真的不需要它......

response不包含文件内容，但包含http响应（包含其状态代码和标题）。

您可以尝试这样的事情：

var AWS = require('aws-sdk');
var https = require('https');
var s3 = new AWS.S3();

var url = 'https://upload.wikimedia.org/wikipedia/commons/thumb/1/1d/AmazonWebservices_Logo.svg/500px-AmazonWebservices_Logo.svg.png';

exports.handler = function(event, context) {
  https.get(url, function(res) {
    var body = '';
    res.on('data', function(chunk) {
      // Agregates chunks
      body += chunk;
    });
    res.on('end', function() {
      // Once you received all chunks, send to S3
      var params = {
        Bucket: 'example',
        Key: 'aws-logo.png',
        Body: body
      };
      s3.putObject(params, function(err, data) {
        if (err) {
          console.error(err, err.stack);
        } else {
          console.log(data);
        }
      });
    });
  });
};

Answer 2

试试这个包https://www.npmjs.com/package/request

var request = require('request');

exports.handler = function (event, context) {
   s3.putObject({
       Bucket: 'example',
       Key: 'aws-logo.png',
       Body: request.get(url, {followRedirect: false})
   }, function (err, data) {
       if (err)  console.error(err, err.stack);
       else console.log(data);
   })
}

aws lambda如何存储在S3中通过https检索的图像

2 个答案: