使用公共访问为文件上传生成预签名URL

Question

我有一个默认ACL设置为private的bucket。我想生成预签名的url，并将其分发给用户，以便他们可以上传文件，上传后文件需要公开访问。

我可以生成预签名的url并上传文件，但文件始终保持私有。如果我在创建签名url时将ACL设置为“public-read”，那么getSignedUrl（）正在生成签名url，但对该签名url的PUT请求会拒绝访问。

var params = {
    Bucket: "bucket name",
    Key: "file key name",
    Expires: 3600,
    ACL:"public-read",
    ContentType: "application/octet-stream"
};
s3.getSignedUrl("putObject", params);

bucket可以包含私有或公共可访问的文件，我想在创建签名url时设置隐私。我怎样才能做到这一点？

我正在使用amazon javascript sdk。

Answer 1

这里来自AWS-S3文档...

看来你必须用艰难的方式来做。

getSignedUrl(operation, params, callback) ⇒ String?
Note: You must ensure that you have static or previously resolved credentials if you
call this method synchronously (with no callback), otherwise it may not properly sign
the request. If you cannot guarantee this (you are using an asynchronous credential provider,
i.e., EC2 IAM roles), you should always call this method with an asynchronous callback.
Note: Not all operation parameters are supported when using pre-signed URLs. Certain parameters,
such as SSECustomerKey, ACL, Expires, ContentLength, or Tagging must be provided as headers when
sending a request.
If you are using pre-signed URLs to upload from a browser and need to use these fields,
see createPresignedPost()....

Answer 2

您可以使用createPresignedPost功能

s3.createPresignedPost({
    Bucket: someBucket,
    Expires: expireSeconds,
    Fields: {
      ACL:  'public-read',
      Key: fileName,
      'Content-Type': fileType,
    }
  });