Question

我是 AWS 开发工具包的新手，我正在尝试检索 S3 中私有对象的预签名 URL。

我发现我的承诺正在以 undefined 的值解析。我怀疑我的 awsBucket 变量没有利用我的 awsConfig，但我不确定如何让两者进行交流。

我的目标是单击更新我的 src 的 img 的按钮以显示存储在 S3 中的图像。非常感谢任何帮助。

以下是我的代码，您可以在其中假设正确填充了秘密/访问密钥。

HTML：

<html>

  <head>
    <script type="text/javascript" src="lib/jquery/dist/jquery.min.js"></script>
    <script type="text/javascript" src="lib/bootstrap/dist/js/bootstrap.min.js"></script>
    <script type="text/javascript" src="js/tableau.extensions.1.latest.js"></script>
    <script type="text/javascript" src="js/index.js"></script>

    <!-- AWS SDK-->
    <script src="https://sdk.amazonaws.com/js/aws-sdk-2.910.0.min.js"></script>
    
    <link rel="stylesheet" type="text/css" href="lib/bootstrap/dist/css/bootstrap.min.css">

    <!-- Font awesome icons-->
    <script src="https://kit.fontawesome.com/d8651426bf.js" crossorigin="anonymous"></script>

    <title>Image from S3</title>

  </head>

  <body>

    <div class="" id="divMain">
      <p>
        <button id="refreshImageButton" class="btn btn-secondary">
            <i class="fa fa-repeat"></i>
        </button>
      </p>
      <img
        id="displayImage"
        src=""
        alt="Placeholder"
      >
    </div>

  </body>

</html>

JS：


var awsAccessKeyID = 'my-access-key';
var awsSecretAccessKey = 'my-secret-key';
var awsBucketName = 'bucket-name';
const URL_EXPIRATION_TIME = 60; // in seconds

var awsRegion = 'eu-west-2'; // Is this the right way to write the AWS Region?

$(document).ready(initialise());

// This function is called when the page first loads
function initialise() {

    console.log('Test')
    // Refresh image button
    $("#refreshImageButton").click(function() {

      let imagePath='1.jpg'
      refreshImage(imagePath);
    });
  }, function () { console.log('Error while Initializing: ' + err.toString()); });
}

// This function refreshes the image using an incoming path from the data
function refreshImage(imagePath){
  console.log(`Image path: ${imagePath}`)

  let preSignedURL = generatePreSignedGetUrl(imagePath, 'jpg')

  console.log(preSignedURL)
  $("#displayImage").attr("src",preSignedURL);

}

//  This function generated the pre signed URL that can access a private object in S3
function generatePreSignedGetUrl( fileName , fileType) {
  return new Promise(function(resolve, reject){
    let awsConfig = new AWS.Config();
    awsConfig.update({
      accessKeyId: awsAccessKeyID,
      secretAccessKey: awsSecretAccessKey,
    })

    let awsBucket = new AWS.S3();
    let awsBucket = new AWS.S3({
      params: { Bucket: awsBucketName},
      region: awsRegion,
    })

    awsBucket.getSignedUrl('getObject', {
      Key: fileName,
      ContentType: fileType,
      Expires: URL_EXPIRATION_TIME
    } , (err , url) => {
      resolve(url) // API Response Here
    });
  })
};

Answer 1

最后，我放弃了这种方法，转而使用 NodeJS 后端。这是我完整且有效的代码：


// Use modules
const config = require('./config');

const AWS = require('aws-sdk');
AWS.config.update({
  accessKeyId: config.awsAccessKeyID
  , secretAccessKey: config.awsSecretAccessKey
  , region: config.awsRegion
});

const s3 = new AWS.S3({signatureVersion: 'v4'});

// Create the parameters for calling listObjects
var bucketParams = {
  Bucket : 'BUCKETNAME',
};

// Call S3 to obtain a list of the objects in the bucket
// This is a good way to test the authentication is working
s3.listObjects(bucketParams, function(err, data) {
  if (err) {
    console.log("Error", err);
  } else {
    console.log("Success", data);
  }
});


var awsGeneratePresignedURLsBackend = function(app) {

  // Enable CORS
  app.use(function (req, res, next) {
      res.header("Access-Control-Allow-Origin", "*");
      res.header("Access-Control-Allow-Headers", "Origin, Accept, X-Requested-With, Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers");
      next();
  });

  // Connection Test
  app.get('/ConnectionTest', function (req, res) {
      res.send('Connected');
  });

  // Slack App Connection Test
  app.post('/generatePreSignedGetUrl', function (req, res) {
      console.log("")
      console.log("--------------------------")
      console.log(`endpoint: generatePreSignedGetUrl`)
      console.log(`type: POST`)
      console.log(`statusCode: ${res.statusCode}`)

      const myBucket = req.body.awsBucketName
      const myKey = req.body.fileName

      console.log(`Bucket: ${myBucket}`);
      console.log(`Key: ${myKey}`);

      const url = s3.getSignedUrl('getObject', {
        Bucket: myBucket,
        Key: myKey
      });

      res.send(url)
      console.log(`url: ${url}`)

      res.end()
  });
}

module.exports = awsGeneratePresignedURLsBackend;

JS AWS S3 SDK getSignedURL 不返回任何内容

1 个答案: